Introduction

It is widely conceived when putting, the closer the ball is to the hole, the higher the conversion rate. The proximity a ball finishes to the hole and strokes gained putting are two common statistics measured within both professional and amateur golf. Strokes Gained Putting [1] quantifies a golfer’s putting performance relative to the field, considering the initial distance of each putt, see Table 1 [2]. Therefore, holing a 10ft putt scores higher than holing a 6ft putt. However, how many times do you hear a commentator say, “They have left themselves a tricky putt here?” When faced with certain putts during a round of golf, why do some putts feel easier than others, even though the putt may be longer?

I can find an 8ft putt that most players of a single figure handicap would be disappointed if they missed and yet I can find another 8ft putt that the chance of even the best players in the world holing is 10% at best – why is this? The proximity to hole is certainly a contributing factor for success rate, however, the following research study was designed to highlight that this is not the only consideration.

Table 1: Make %, 3 Putt % [2] and Strokes Gained data from ShotLink, recorded on the PGA Tour [3]
(Please note highlighted in red font: distances used in this study are between 8 – 13ft)

Methods

The Quintic Overhead Putt Tracker system [4] uses a high-resolution camera (2024 x 1200 pixels) recording at 100 frames per second (fps) positioned 2.70 metres above the playing surface. The overhead camera was placed in the centre of the Zen Green Stage [5]. The dimension of the stage used for the study was 16ft x 8ft with the artificial surface stimping at 10.5 on the ‘Level’ setting.

The following parameters were recorded for each putt: impact ball speed, start direction, point of true roll, apex, separation point, entry speed, entry angle, total distance travelled, time to hole, sliding phase %, rolling phase %, decay phase %.

Figure 1 : Example Putt captured with Quintic Overhead Putt Tracker

The six different putts chosen for the study were replicas of six famous putts in golfing history. The order of the six putts were randomised for each of the 35 subjects. Once the Zen Green stage had come to rest in the new putt gradients, video footage of the successful putt was played to the subject prior to performing that specific putt. The data capture was “embedded” into a competitive game format whereby the participants were asked to compare their performance against historically significant putts. This further encouraged the players to exhibit more representative performance behaviours. In addition, it also provided additional information regarding reading the putt, notably ball speed, slopes and direction the golf ball moved during the putt. The subject was then allowed a further 40 seconds to read and execute the putt. Each of the six putts were attempted by 35 golfers (handicap ranging from 24 to +3).

Table 2: Putt description and slope gradient of the Zen Green Stage for each of the six putts

Figure 2 is a representation of all 35 attempts for Putt 6. The straight-line distance for this putt was 13’ 3” with the Zen Green stage set to the following gradients, 1.5% Downhill and 4.5% Left to Right. The average distance travelled for the putt was 14’ 5” for the three holed putts (an 8.4% increase in the straight-line distance).

Figure 2: A visual representation of all 35 subjects attempt of ‘Putt 6’
John Rahm, 2021 US Open Torrey Pines 17th Green

Results

The first part of the study was to investigate the percentage make rate for the 6 different putts.
35 putts were made for each putt location.

Table 3: Putt description and slope gradient of the Zen Green Stage

The highest make percentage was Putt 1, 8ft with a subtle 1% Downhill and 1% Left to Right break. 13 out of the 35 putts were successful (37%). This is still significantly lower than the PGA Tour average 46.6% conversion rate.

Putt 2 Seve Ballesteros, 1984 Open Championship winning putt on the 18^th green of St Andrews had an 11% conversion rate (the PGA Tour average for 11ft is 32.4%). It is interesting to note that this was the only uphill putt of the 6 putts analysed.

The lowest conversion rates (9%) were Putts 3 & 6, both of 13ft feet in length and with considerable break.

However, Putt 5 (13ft in length) Phil Mickelson, 2004 Masters, Augusta National 18^th Green had a success rate of 26%, the second highest and over double that of Putts 2, 3, 4 and 6.

Figure 3 : Graphical representation of all 6 putts (35 subjects)

Table 4: Putt number with the average, Standard deviation, range for all 35 attempted putts

The lowest range in start direction was Putt 4, 9.23° (but only an 11% conversion rate). The largest range was Putt 6 28.98° (9% conversion rate)

Putts 2 and 4 were of 11ft in length. Putt 4 has a lowest range in start direction range along with a higher average impact ball speed (both putts had an 11% conversion rate).

Putts 3, 5 and 6 were all of 13ft in length. Putt 6 has the highest range in start direction and the highest average impact ball speed.

Figure 4 : Graphical representation of all successful holed putts for the six different start positions.

Table 5: Average, Standard deviation, range for all successful putts

The above table highlights the data from all successful putts for the six different putt locations

The putts that had the highest success rate also had the greatest range in impact ball speed. Putt 1 (8ft) 37% success rate had an impact ball speed range of 1.29 mph for the 13 successful putts.  Putt 5 (13ft) 26% success rate had an impact ball speed range of 1.96 mph for the 9 successful putts.  The remaining 4 putts had a success rate lower than 11%. It is interesting to note that ranges for the ball speeds for successful putts was 0.27 mph for Putt 2, 0.79 mph for Putt 3, 0.47 mph for Putt 4 and 0.62 mph for Putt 6.

Figure 5 : Image of a successful holed putt (Putt Location 5)

Straight Line Distance 12’ 10”, Total Distance Travelled until inside hole 13’ 0”,
Area under the curve 1.6 sq ft (Light green section), Apex Distance 3”
Time Taken 2.49 seconds (Start position to fully inside the Hole)

Figure 6 : Image of a successful holed putt (Putt Location 6)

Straight Line Distance 13’ 2”, Total Distance Travelled until inside hole 14’ 4”,
Area under the curve 18.84 sq ft (Light green section), Apex Distance 2’ 6”
Time Taken 3.76 seconds (Start position to fully inside the Hole)

Table 6: Average, Standard deviation, range for all successful putts:
% increase in distance travelled, area, apex distance from straight line and time taken

Table 6 highlights the data from all successful putts for the six different putt locations. The % distance increase, apex, area, and time taken for the successful putts are highlighted. Putt 2 and Putt 4 had the lowest area (sq ft), however both only had an 11% conversion rate. Putt 4 and Putt 5 both had similar time to hole (3.18 and 3.10 seconds respectively) but had very different conversion rates (11% and 26%).  Putt 6 had the greatest Apex distance (2’ 6”) but still had the same conversion rate as Putt 3 (Apex distance 6”). The % increase (Straight-line distance vs Actual Distance travelled) is a very small amount for 5 of the 6 putts, despite some of the putts having over 2% slope. Putt 6 had an 8.4% increase in distance.

Discussion

The putt with the highest % conversion rate was Putt 1 (8ft distance). This was the closest putt from all six putts recorded. It is interesting to note that only two putts missed left (high) of the hole, the remaining 57% missed low. Putt 1 was a very subtle 1% Left to Right and 1% downhill. Can the human feel the 1% slopes? 15 putts (43%) of Putt 2 were short – they never even made it past the hole. Again, asking the same question, can a human feel 1% slopes, this time uphill? Putt 6, prior to the experimental testing, would have been deemed the hardest putt of all six. With a 9% conversion rate, it could easily have been lower, given one person was extremely lucky to hole the putt with a ball entry speed of 2.2mph. At this entry speed, the effect cup size is significantly reduced, and if it had missed it was going to be a long way away! This putt took only 2.69 seconds, whereas another holed putt for Putt 6, which had an entry speed of 0.8mph, took 5.25 seconds to reach the hole.

The putts that had the highest success rate also had the greatest range in impact ball speed. Putt 1 (8ft) 37% success rate, had an impact ball speed range of 1.29 mph for the 13 successful putts. Putt 5 (13ft) 26% success rate had an impact ball speed range of 1.96 mph for the 9 successful putts. The remaining 4 putts had a success rate lower than 11%. The lowest ranges for the ball speed for successful putts was 0.27 mph for Putt 2, thus requiring a very consistent touch and control of the putter head speed, acceleration and ball impact location.

Figure 7: The effects of ± 50 percent errors in the initial trajectory (left) compared to the effects
of only ± 10 percent errors in the putt speed (right).  [6]

The ability to control ball speed can often be overlooked in coaching. The data reported in this study goes to further corroborate the results stated by Dewhurst (2015) “Speed is more important than target line” [6]. Ball speed is one of the four reasons as to why a putt might miss [7]. The ability to control the speed of the putter head with controlled face aim, along with green reading, are also primary determinants of putting consistency [8].

Putt locations from both clock face positions 2 o’clock and 10 o’clock have the lowest conversion rates, because you have a smaller margin for error with ball speed in these starting positions [9]. (Note: 12 o’clock straight downhill, 6 o’clock directly uphill).  Ball speed is not only influenced by clubhead speed at impact, but also length of backswing and clubhead acceleration during impact, time taken and the tempo of back vs through swing along with the % speed drop at impact. As the slope gets steeper the variance in how the ball slows down (Launch angle, vertical bounce, sliding/rolling/decay phases of the putt) creates inconsistency in final distance. The smaller uphill angles are more forgiving of speed variances than cross-hill or downhill angles.

Therefore, from a strategic perspective of playing the game of golf, it should be obvious where the ideal position to putt from is and from a performance perspective it is important to understand that having consistent ball speed control will have a big effect on distance control. Despite this, some natural variance in speed must be expected (golf is an outdoor sport), and when facing a steep fast downhill putt, it is dramatically harder to make than the equivalent uphill putt [10] [11].

Putt 5 had a 26% conversion rate, despite being 2^nd longest putt tested (13ft). Putt 1 (8ft) had the highest conversion rate of 37%. This study is a preliminary investigation into the notion that not all putts of the same length are equal. The proximity to hole is certainly a contributing factor for success rate, however, this research highlights that this is not always the case. Severity of slope, ability to read the slope, start direction, time the ball is in motion, area under the curve, ball speed, apex and ball entry speed are all factors that contribute to the ‘difficulty of the putt.’

This is an area for further research to understand all the various parameters that contribute to making a successful putt. Ball speed variation has been identified as a key variable for indicating success, but until we further investigate this topic by increasing the number of subjects and putt locations, we are left with proximity to the hole and strokes gained as the key factor for success in putting. This study provides a rationale to challenge the current metrics and statistical methods and opens up new opportunities to capture data that may identify how the player acquires greater awareness of their adaptative behaviours within a performance environment.

Figure 8: Image of a two successful holed putts (Putt Location 6)
14.92° difference in start direction, but only a 0.36mph difference in impact ball speed

Finally, take for example the John Rahm winning putt on the 18^th green at Torrey Pines, 2022 US Open (Putt 6). In Figure 8 above you can clearly see two different ways to achieve the same result, a holed putt. The putts have very different entry speeds, therefore consequently they have very different start directions. There is a lot more tolerance than people might think – attention can be focused on different areas of the task, as opposed to be thinking it is all about start line. Quintic Overhead Putt Tracker enables you to analyse the whole putt and break down the various phases of the putt. During this research study it became obvious to that golfers need to broaden their horizons, enhancing their perception and visualisation of the putting landscape. The golfer needs to be much more mindful about the environment they are facing. How do you correctly access the green contours, slope, grain, wind and ultimately visualise the ball’s path and entry speed into the hole?

The second putt takes almost twice as long to reach the hole, resulting in a ball entry speed of 0.8mph. As a result, the effective hole size is much larger than when a ball reaches the hole at 2.11mph. Quintic provides the numbers to help support the feeling and sensation of the player. The ability to constantly challenge the golfer by moving the Zen Green Stage to a new location, in combination with the Quintic data, adds texture and meaning to the whole learning experience.

The existing learning space is constrained. Practice putting greens are large and generally flat, the access to the golf course where the greatest opportunity to learn is often restricted. The combination of Quintic and the movable putting stage transforms the existing practice and learning space. It explores new opportunities to enhance the coach’s knowledge base and coaching practices, as well as the providing the essential interface between the practice and performance landscape. The ability to provide a greater array of realistic putt trajectories releases new opportunities to enrich practice environments. This enables the player to explore the task, gain meaningful feedback from essential data and broaden their appreciation of the key aspects that improve performance such as coupling perception and action e.g: 10 & 2 o’clock putt results on the clockface. How people practice ball impact speed and pace control is an area of further investigation. You can’t choose your start line until you know what speed the ball is going to enter the hole!

Acknowledgments
The author would like to acknowledge and thank the assistance and contribution of Mr Nick Middleton (Founder of Zen Golf) for his invaluable assistance and advice during this research project.

References

1. Broadie, M. (2014) Every shot counts. Penguin Publishing Group
2. Stagner, L. (2019) https://x.com/LouStagner/status/1200806231352528896
3. https://www.pgatour.com/stats/putting
4. 2024. “Putting Analysis Software Systems – Quintic Ball Roll.” https://www.quinticballroll.com/Quintic_Ball_Roll_Systems.html
5. Zen Green Stage (2024) https://zen.golf/
6. Dewhurst, P. (2015). The Science of the Perfect Swing. Oxford: Oxford University Press.
7. Cochran, A. J. & Stobbs, J. (2005). Search for the Perfect Swing. Chicago: Triumph Books.
8. Karlsen, J., Smith, G, Nilsson, J (2008). The stroke has only a minor influence on direction consistency in golf putting among elite players. Journal of Sports Science, February 1^st 2008; 26(3): 243-250
9. Hurrion, P. (2016) Speed Changes Everything – an investigation into the effect of launch characteristics on putting performance WORLD SCIENTIFIC CONGRESS OF GOLF, July 18-22 2016 : St Andrews, Scotland, UK.
10. Holmes, B. W. (1991). Putting: How a golf ball and hole interact. American Journal of Physics, 59, 129-136.
11. Wesson, J. (2008). The Science of Golf. Oxford: Oxford University Press.

We hear it all the time, don’t we… As a player prepares to roll a birdie putt from mid-to-long range (10 feet and out), the commentator reminds all of us at home that in order to have the best chance of making the putt it has to be rolling at a speed that would see the ball finish 18 inches beyond the hole should it miss.

Well, maybe this is not entirely true… I have been recently been conducting new research into this theory, in part due to the new developments of the Quintic Overhead Putt Tracker.   The software tracks the complete path of the golf ball throughout its journey, measuring parameters such as ball speed, aim location, start direction, apex, point of true roll, total distance and the all-important ball entry speed.

In order for a player to hole a successful putt they must understand the various factors which alter the deceleration rate of the ball. Based on the understanding that the ball-surface relationship is what provides the frictional properties, it is critical for a player to understand how the various types of playing surface may affect this ball-surface relationship. For example, a grainy green may have a higher coefficient of friction than a non-grainy green. Different types of grass (Bent, Fescue, Ryegrass, Bermuda, Zoysia, Poa Annua…) will also have various frictional properties, such as coarser fibres, leading to an alteration in ball behaviour.  The length at which a particular type of grass is cut and the density of the grass will also influence the ball-surface relationship. In addition, the slope, moisture levels and even wind strength and direction can alter the ball-surface relationship and should be considered by the golfer before committing to a line.

The optimum entry speed of a putt is often significantly slower than we are all led to believe, and largely dependent on the amount of break. The reasoning is simple: the faster a ball is travelling, the smaller the effective size of the hole becomes and so the more accurate you need to be to set the ball on the perfect line. Given that it is easier to control the speed of a rolling ball than the precise angle of the putter-face at the moment of impact, one such method of putting is to focus on ‘dying’ the ball into the hole, therefore reading maximum break. One of my long-time students, Padraig Harrington, has always been one to die the ball into the cup (for mid to long-range putting) and much of the time we have spent on the putting green revolves around adjusting the ‘reading’ of the putt to maximise the effective size of the hole as the ball approaches. As a result, the entry point of the hole moves around the clock face according to the severity of the slope. At drop-in speed the ball is obviously going to take more borrow than a ball entering the hole at 2 mph. Visualisation of the balls path and entering the hole from the higher side due to its dead weight speed is a skill that requires practice.

Choosing the correct speed is vital in order to work out your intended line. Where does the ball enter the hole? To help with the visualisation of the true break of the putt, I would always encourage a player to visualise a clock face – at which point does the golf ball enter the hole? A key point here is to not stop visualising at the front lip of the hole – continue through and even out of the back of the hole! This is one reason why I love to use ghost / phantom holes (plastic disks that replicate the size of a golf hole that you can move around the green surface) because you see the entirety of the putt, unlike a real hole, where, although you have the satisfaction of seeing the ball drop, you don’t get to view the end position of the ball.

In the example above (Captured from Quintic Overhead Putt Tracker www.quinticballroll.com), the ball is entering the hole at 7:00 (212°) and speed of 1.46 mph, but how far past would it have gone?

In the example 12 putt shown above, (Putt 17) the ball enters the ghost hole at 7:00 (207°) with a ball speed of 1.08 mph. Note the green line that depicts the ball’s trajectory and how it changes abruptly after passing through the ghost hole. It follows the slope of the putting surface as indicated by the small green arrows (3% Left to Right, 1% Uphill).  The ball finishes 7” away from the middle of the hole.

In a subsequent putt (same start putt location – Putt 18), the ball enters the hole at 6:30 (200°) with a speed of 1.29 mph (An increase of 0.21 mph). Note the subtle difference in the trajectory. The ball has finished 15” away from the middle of the hole, despite having a lower impact ball speed.

The above image has both putts displayed simultaneously. There is only 0.13mph difference in impact ball speed. It is interesting to note that Putt 18 (Orange trajectory) was hit with the lower impact ball speed, (5.78mph), but is actually going faster at the hole, as a difference of 1.46 degrees or 3” higher in the start line, means the ball is travelling up the slope for longer. The ball with the higher start line  (-22”) has an apex of 10” compared to the lower start line (-19”) of 7”. Ball speed influences the line required to make a successful putt. As both putts were holed, it is interesting to note how just 0.13mph impact ball speed and a 3” difference in start line can affect the ball’s path, ball entry speed and finish position.

On a 15-foot putt, a deviation of less than 0.5° in the angle of the putter-face is all that’s required for you to miss your line and the hole – you’d have to be a robot to believe you could consistently keep the face dead square to your starting line! What’s more, if you are someone who likes to roll the ball at pace (the “18 inches beyond the hole” approach), you are effectively shrinking the hole to less than a third of its actual size! You can read more on this previous research at the following webpage: https://www.paulhurrion.com/tuition/an-investigation-into-golf-ball-speed-at-hole-entry/

Therefore, it would suggest that the odds of success are considerably greater if you focus on rolling the ball at a speed that would see it travel perhaps just three or four inches beyond the hole (should you miss), provided you read the full extent of the break.

The above image is taken from Quintic Ball Roll v4.4. The putter face angle was measured at 0.59° open at impact. 15ft is the maximum distance the ball has the possibility of being holed at dead weight.

The science proves the argument. For example, if you are facing a 10-footer on a 3% uphill slope – for the ball to finish 30cm (12 inches) past the hole, the speed of the ball at the point of entry is 180% faster than the pace of the corresponding putt downhill.  At this entry speed the hole is effectively three quarters of its actual size, and that’s a lot to give away.

The diagram above highlights the effective size of the hole for the “30cm or 12” past the hole for both uphill (6 o’clock entry) and downhill (12 o’clock entry). The hole is a lot bigger when coming downhill as the ball is moving slowly! You effectively have 96% of the hole to play with on a putt that is travelling so much more slowly.  Interestingly, on a FLAT putt, to finish 30cm past the hole (Stimp 10) you only have 87% of the hole size available.

If you are 5 feet away and a little unsure of the break, then you might decide to take the risk and stroke the putt a little more firmly. But be aware that the harder you hit it, the smaller the effective hole becomes. The ball won’t drop in even if rolls over the perfect centre of the hole above 3.64 mph (1.63 m/sec), The Physics of Putting, A.R. Penner (February 2002) Canadian Journal of Physics 80(2): 83-96.  There may be a chance it hits the pin dead centre and drops in, but you would have to leave the flag in for that… and that’s a different debate entirely.

The image below is from R. Chiono, (www.roechigolf.it) and gives a fantastic visual description of the how different entry ball speeds behave as they reach the hole.  Above 2.90 mph or 1.3 m/sec the ball doesn’t have time to drop sufficiently under gravity. The equator of the golf ball hits the opposite side of the hole. At 3.64 mph (1.6 m/sec) the ball may still potentially have a chance, but a very slim with no flag present.

Ok, now for flip side of the argument, because I would argue statistically, we don’t hole more downhill putts? If anything, if you had to choose a spot on the clock face to hole an 8ft putt for a tournament win, most players would choose an uphill, slightly breaking (inside the cup) putt. Hopefully, the next part of the article may explain why they do this…

There are four phases to the ball’s speed during a putt: Launch, Sliding, Rolling and Decay.

Phase 1 – Launch: (Smallest Distance covered by the ball). Projectile equations of motion can be used when a ball is in flight. Quintic Ball Roll measures each individual frame, calculating both the Ball Launch angle and the Flight angle. Anything more than 1 degree difference would indicate surface interaction and the ball being trapped into the surface. During the ‘Launch Phase’ essentially there is little or no change in ball speed. In the example below you can see for the first 3” the ball speed is constant (4.65 mph). The ball is airborne (no contact with the surface to slow it down) as a result of a positive 3.00° launch angle. However, on landing, the ball speed typically takes a significant drop, before entering the sliding/skidding phase.

Phase 2 – Sliding / Skidding Phase: This phase is a combination of sliding and rolling. Remember the ball doesn’t suddenly go from 0% rotation to 100%. As the ball is increasing in angular rotation (forward spin) caused by the friction and interaction with the putting surface, its linear (horizontal) speed is decreasing. The point at which the rotational speed and linear speed are equal is the point when the skidding (slipping) stops. At this moment, the sliding frictional force disappears and the third phase begins: Rolling. The sliding frictional force is different to that of rolling friction. We know that a golf ball will decelerate at the quickest rate during the sliding / skidding phase.

Phase 3 – Rolling: This is the largest % of the ball’s journey. The Rolling resistive force is a constant force which is determined by the deformation of the surface, but independent of the velocity of the ball. An example of the deformation of the putting surface would be the grass height. Energy is lost due to the rolling friction (essentially the ball flattening the blades of grass).

Phase 4 – Decay Phase (Unpredictable Rolling): As the angular rotation of the golf ball begins to slow down, so does the linear velocity. There comes a point (depending on the surface, gradient) where the ball no longer has the momentum to continue and flatten the blades of grass. At this point, the ball has a sudden drop in speed. During the ‘Decay Phase’ the golf ball is very unpredictable – you can often see marked deviations in the ball’s path using the Quintic Overhead Putt Tracker. We have all played golf and had a putt tracking to the hole, only at the last second to deviate unexpectedly as the ball runs out of pace. It is interesting to note that the ball speed when this ‘Decay Phase’ begins is approximately 1mph across numerous types of putting surfaces.

Example Putts:

1) Dead Weight (Ball finishes on top of the ghost hole)

In the example above of a dead weight putt, the ball comes to rest directly on top of the ghost hole. The images highlight the position of the golf ball when the start of the ‘Decay Phase’ begins. The Ball Speed is 1.12mph at the start of this phase, but there is still 12” of the ball’s journey to go. The last 12” of the ball’s final journey is unpredictable and at the mercy of any green imperfections, especially evident on poor, bumpy, grainy greens…

2) Ball finishes 10” away from the ghost hole

The images highlight the position of the golf ball at the start of the ‘Decay Phase’. The ball is going to miss on the low side, but interestingly the Ball Speed at the start of the Decay Phase is 1.12 mph. There is still 12” of the ball’s journey to go. The ball finished 10” from the hole.

3) Ball finishes 34” away from the ghost hole

The images highlight the position of the golf ball at the start of the ‘Decay Phase’. The Ball Speed is 1.11mph at the start of this phase. However, in this example the ball has already passed the hole. The ball was still in the rolling phase as it passed the hole and ultimately finished 34” away from the hole.

4) Ball finishes 52” away from the ghost hole

The golf ball has not reached the start of the ‘Decay Phase’.   In the example above the ball speed at the hole is 1.94 mph. The ball disappears out of shot still at 1.27 mph. The final end position was 52” away from the hole. (This was measured manually as the ball disappeared out of the camera view)

5) Ball finishes 10” away from the ghost hole: In this example, the start of ‘Decay Phase’ occurs just as the ball is entering the hole. The golf ball is still in a predictable phase of its rolling and is maximising the size of the hole.

Is this the optimal ball speed to enter the hole for this particular putt?

6) Maximum possible slope. In the following example using an indoor Zen Green Stage (https://www.zengreenstage.com/) the angle of the stage is set to a 4.5° Right-to-Left planar slope. Any greater than this and the ball would not come to rest (this is known as the ‘angle of repose’, the steepest angle at which a sloping surface formed of loose material is stable). In practical terms, if you increased the slope of the platform to 5.0° it wouldn’t be possible to place the ball still on the surface – once you let go it would begin to roll away… The ‘Decay Phase’ in this example begins at 0.91 mph. Notice how the gradient shallows out on the ball speed graph at this point as the ball is slowly trickling down towards the hole. The ball still has an unpredictable path, even on an indoor artificial carpet, for the final 3’ 8” of its journey. Eventually, the ball comes to rest 13” past the hole. The ball was moving for a total of 8.31 seconds for a 12ft putt. Interestingly, 4.7 seconds of the putt’s journey occurred when in the decay phase (57% of the time taken).

Summary:

• Ball speed is a key component in order to putt successfully. Pelz, (2000) suggested that 80% of putts were missed due to poor speed control, highlighting the importance of understanding this relationship for any golfer.
• Rojas, 2004 stated the ball decelerates linearly until a threshold is reached, and the ball stops dead. Rojas & Simon, (2014), state that once kinetic friction disappears (when the ball begins rolling) there is a linear deceleration until the ball reaches a threshold, where it ceases to travel. However, research provided by the Overhead Putt Tracker would suggest the ball speed is not linear.
• Aiming to leave the ball ‘dying’ in the front edge vs 1 foot or even 2 feet past the hole has a marked effect on the required ball speed, start line and effective hole size, particularly when putting on a slope.
• Entry speed and direction needs to be specific to distance, slope & stimp and may also vary depending on a person’s preference and style of putting (dead weight, 12”, 18″ or even 36″ past the hole)
• Remember, once the ball drops below 1 mph it becomes very unstable and unpredictable. The speed drop off is significant. The ball no longer has the angular momentum and energy to stay on top of the surface. It is at the mercy of any imperfections in the putting surface.
• Future research is going to focus on different slopes, grass types, moisture, grain and length of grass to measure ball speed at the start of the decay phase.
• Moving to the real world and how to implement this into practice and coaching: What is 1 mph on the putt you are facing? Should you be aiming to achieve 1 mph just as the ball enters the hole rather than a set distance past the hole? 1 mph ensures the ball is still in true roll and maximises the hole size.
• However, at 1 mph on stimp 12 with a 3% downhill, the ball could easily run 4ft by the hole! Do you want to have a 4ft return putt? Especially if there is a degree of break on the return putt? Therefore, in order to finish 12” past the hole, the golf ball will be in the unpredictable ‘Decay Phase’ prior to reaching the hole. There is now a trade off! Predictable roll vs distance past the hole – the player must decide…
• 1 mph ball speed on my indoor surface (Level) in the putting studio travelled 0.65m (26”) Stimp 15.
• 1 mph ball speed on an outdoor putting green (Bent Grass, Level) travelled 0.3m (12”) Stimp 9.5.
• 1 mph ball speed on an outdoor putting green (Bent Grass, 3% Uphill) travelled 0.15m (6”) Stimp 9.5.
• Golfers should be encouraged to visualise the curve of the putt and how their speed will affect that curve. Optimise the effective size of the hole and entry point in order to give the best chance of holing the putt.
• Don’t always try to finish a set distance past the hole – work out what 1 mph ball speed will do to the distance travelled for the putt you are facing!

If you have any questions or would like to add your input to the article, please email info@paulhurrion.com  Thank you.

The anchoring rule states that while making a stroke, a player may not anchor the club (i) “directly” or (ii) indirectly through use of an “anchor point.” Since nothing is anchored to the butt of the putter grip, the arm lock putting style is completely legal and conforms to the Rules of Golf (R&A / USGA)

What is Arm Lock Putting?

• While it may look odd to some, using an arm lock putter can be extremely effective for players who are ‘handsy’ and may even have the ‘yips’ on the putting green. The arm lock putter reduces your ability to move your hands during the putting stroke? However does it…
• The idea of “change” to a golfer is often a no go area, especially in putting, as the are often traditional, a player likes repetition and routine.
• To change a putting style that you have been accustomed to since you took up the game would be unheard of for many golfers.
• And let’s admit – it does look a little strange!!!

Analysis

• 2D Quintic Biomechanics (100fps video analysis)
• 4 Cameras
• Quintic Putting Report
• Quintic Ball Roll v4.4 720fps
• 3 Putter used – details below
• I was the subject for the data collected – Putted all my life conventional style, the data from the Arm Lock putters was the results of a number of hours practice.

i) Standard Length 34” EvenRoll2 (Blade) 340gm HW P2 Grip 3°Loft  68.5° Lie
ii) Arm Lock EvnRoll2 39” Length Super Stroke Armlock Grip 1.0 8.5°Loft  68.5° Lie
iii) Arm Lock – Midlock Grip EvnRoll ER5 (Hatchback) 370gms HW  39” Length  4.5°Loft  68.5° Lie

Experiment 1 : i vs ii            Experiment 2 : ii vs iii

Biomechanical Analysis

• 2D Quintic Biomechanics (100fps video analysis) 4 Camera Synchronised. Infra red camera and lighting enables the automatic tracking of the 10-point template. Data is reported via the QuinticPutting Report

• 2D Quintic Biomechanics (100fps video analysis) IR Light – 10 Point Putting Template

• 2D Quintic Biomechanics (100fps) Quintic Putting Report – over 100 parameters measured

* Experiment 1: Quintic Ball Roll (i) Red = Standard Putter (ii) Blue = Armlock – SuperStroke Grip

Min, Max, Average, Std Deviation and Range

* Experiment 2 : (iii) Red = Armlock Midlock Grip (ii) Blue = Armlock – SuperStroke Grip

Key Findings : Reasons for using an Arm Lock Putter?

• The arm lock (AL) putting style has the putter remaining “locked” to the golfer’s lead forearm throughout the entire putting stroke. This reduced the movement (distance travelled) of the pivot point when using AL method.
• The AL putter minimizes your ability to move your hands during the putting stroke (i.e. decrease in putter head rotation) -44°/sec closer rate with a standard putter and grip to -31 to -24°/sec with standard AL and a further reduction to -22°/sec with the EvnRoll Midlock grip… a 50% reduction in face rotation.

• With the putter held against the lead forearm, it creates a bracing effect that keeps the putter head from rotating during impact and through the stroke. The range of putter head rotation decreased with AL style grips. More repeatable! The ability of your trail hand to apply pressure to the butt-end of the grip to ensure the grip maintains contact with your lead forearm can only help explain the reduction in face rotation.
• The putting stroke is controlled through the shoulders / torso while keeping your head still. Reduced movement of the sternum and head during the putting stroke, resulted in a more consistent ball speed with the AL style putters.
• Head Displacement Address to Impact

• When your arm lock putter is secured against your forearm, the proper loft (significantly higher static loft than when in standard posture) can be achieved and repeated under pressure. Data from Quintic Ball Roll showed an improvement in consistency for ball launch angle when using the AL putting method.

• The player will always keep their hands ahead of the putter head through the stroke naturally. This will help create an upward attack angle (ensuring correct ball position) allowing the ball to roll smoothly off the club face with better topspin and consistency. The data supports a more consistent forward roll from the AL style putters (lower range). This is due to a more consistent pivot point and ball launch angle.

With a 50% reduction in face rotation, this is very significant for holing putts inside 20ft when under pressure…

Introduction

When using a putting robot for testing and research and development, nearly all numbers produced by Quintic Ball Roll, including face angle, face rotation, path, attack angle and low point, record very consistent results with a small range and standard deviation. One of the features of Quintic is to colour code this range to highlight consistency. Within Quintic, ranges recorded using a putting robot are coloured blue. The following table (Table 1) highlights the ranges for the various parameters recorded by Quintic Ball Roll. For a Blue Face angle range, a minimum of six putts are required within a range of <0.5 degrees.

Table 1. Quintic Ball Roll – Range Colour Coding

The one parameter, however, that generally has a larger range despite using the robot, is the ball launch angle. This was also noted by Richardson et al 2017 when looking at the effect of dimple error on the horizontal launch angle and side spin of the golf ball during putting. A possible explanation for this is shaft vibration and oscillation caused by the putting robot during transition. Research into the shaft movement while in a putting robot and high speed camera (5000HZ), has shown that the pull back motion of the machine causes vibration and oscillation in the shaft. (Figures 1 and 2)

In the example below (figure 1), reflective markers were attached at regular intervals points along the putter shaft, and their velocities were measured through the transition from the backswing to the downswing during the stroke.

Figure 1. Images displaying the experimental setup: putter in the robot (A),
the seven point reference model used during Automatic Tracking (B),
and digitised trace for seven markers of the shaft and toe (C).

Figure 2. The above graph highlights the velocity of the seven markers
during the putter’s transition and downswing (Blue Vertical line = Impact)

The analysis showed a range in the velocity of the toe end of the putter shaft, most likely caused by the oscillation of the shaft. This change in velocity at the bottom (putter head) compared to the top (grip) would also cause a change in dynamic loft of the face. Ball position and the acceleration profile of the putter could potentially cause the loft to be different nearly every time the putter face makes contact with the ball. Based on the following observations of the shaft oscillating during the downswing, the purpose of this study was to test the consistency of the ball’s launch angle using three different positions of the shaft.

Method

The Quintic Ball Roll system uses a high-speed camera (1080 fps) to measure a variety of parameters. This study was focused on two of these parameters, ball speed and launch angle. A 35″ centre shafted putter (Head weight 355gm) was set into the putting robot (figure 3). The shaft was positioned vertically and the ball position was 1.5cm in front of the resting position of the putter head to create a small positive attack angle. The putter had 3 degrees of static loft (to ensure no surface interaction). The grip was removed for repeatability of the three different attachment points within the putting robot. The three different locations for clamping the shaft to the robot can be seen in figure 4: The top/handle (1), the centre of the shaft (2), and at the point where the hosel enters the putter head (3). The clubhead was released at three different speeds, on a straight back and straight through path in order to create ball speeds of 3, 6 and 10 mph. The same putter and ball was used throughout the study.

Figure 3: Quintic Ball Roll v4.4 Research Edition (1080 fps)

Figure 4: Putting robot in use.

Thirty putts were recorded for each speed and shaft location. The protocol was conducted on an indoor artificial putting surface (Stimp 12). Ball speed and launch angle were recorded for the 3 different speeds and locations using the Quintic Ball Roll System (1080fps).

Results

Tests with putter connected at the grip/top (location 1)
The first step of the study was to test the launch angle with the full length of the shaft clamped to the putting robot – this was 5″ from the butt end of the shaft, replicating the location of the player’s hands on the putter grip.

Tests with putter clamped half way down the shaft (location 2)
At this point the putter was connected at the halfway point of the shaft and the same tests were repeated.

Tests with putter clamped at the bottom of the shaft (location 3)
This series of tests were run with the putter clamped directly at the hosel (as low as possible), meaning in theory, no putter shaft was involved.

Summary

• Increasing ball speed has the effect of making the ranges narrower/smaller and the launch angle is more consistent.
• The lower down the shaft is clamped to the putting robot, the smaller the range in launch angle. The reduced range is more than likely a result of less shaft vibration / oscillation during the downswing.
• Shaft and ball speed are shown to have an effect on launch angle consistency.

Practical applications

At 3mph (low ball speed), the range of launch angle was the highest irrespective of where the shaft was clamped.

At 6mph ball speed, the ranges in launch angle are lower than at 3mph, while at 10mph ball speed, the ranges are the lowest. Is this potentially due to the increased compression of the golf ball at the higher speeds?

The range and standard deviation were more consistent across all three ball speeds when clamped as low as possible to the putter head, when compared to the top of the shaft. Shaft vibration and oscillation is certainly influencing the consistency of launch angle. This is important for the player and coach to be aware of, so they can ensure tempo and transition are as smooth as possible.

• A reduced range in the ‘Shaft Angle’, resulted in a reduced range in the ‘Launch Angle’, which in turn caused the time to ‘Zero Skid’ to be more consistent.
• Subsequently, the more consistent a golf ball reacts on first contact with the surface the greater consistency for the ball speed at ‘true roll’.
• The distance to ‘true roll’ is an important factor for determining pace control. How a ball slows down, will determine where the ball takes the break!

Lots of testing and research is carried out using the putting robot, as it is the gold standard for most research involving any form of repetitive putting motion. However, if a test involving the putting robot is focusing on launch angle or something affected by launch angle (forward spin, zero skid, etc.) then results potentially may be influenced by the shaft and location of the clamping of the putter to the robot. Based on the fact that we now know shaft effect is taking place, if a test is to be more accurate then certain parameters can be changed, such as the point at which the head is clamped in the robot, which should reduce the range of the launch angle, and make any research carried out on the robot more reliable and repeatable.

Further research

From this study we have learned that the vibration of the shaft can affect the consistency of the launch angle of the golf ball, but we also learned that ball speed has a big effect too. A future study would be to test different putter styles, with a variety of different speeds, to see if the trend remains the same, and see why faster ball speeds seem to create more consistent launch angles.

References

Richardson, A.K., Mitchell, A.C. and Hughes, G., (2017). The effect of dimple error on the horizontal launch angle and side spin of the golf ball during putting. Journal of sports sciences, 35 (3), pp.224-230.

Quintic (2020). Quintic Consultancy Limited, Unit 8, The Courtyard, Roman Way, Coleshill, Birmingham, B46 1HQ (UK) (www.quinticballroll.com)

Purpose

Many of today’s putters are still based on the original ‘Ping Anser’, designed originally by Karsten Solheim, a Norwegian-born engineer who worked on jet fighters and missile guidance systems after World War II. In March 1967, Solheim was granted a patent for what would become perhaps the most iconic putter design the game has ever known.

Figure 1: Karsten Solheim’s original drawings of the Ping Anser putter.

Solheim’s patent expired in 1984, leading to a number of copycat designs from different manufacturers that continue to this day. The Ping Anser-style putter is utilised by tour professionals the world over, along with millions of everyday golfers. The following study investigates the difference on the ball impact parameters when comparing ten ‘Ping Anser’ style putters, each from a different manufacturer. All ten putters used for the study are available today for purchase from any major golf retailer. Using a repeatable putting stroke on a robot, how does the different materials, overall weight, centre of gravity location, insert technology, moment of interia, head weight, swing weight and shaft affect the golf ball and club head during impact? Even though the basic design is the same to the ‘lay person,’ how differently do the putters perform?

Figure 2: George Archer became the first golfer to win a major using the above Ping Anser putter when he was victorious at the 1969 Masters.

Methods

The Quintic Ball Roll v4.4 Research system (Quintic, 2019) uses a high-speed camera (1080 fps) to measure factors such as ball speed, club speed, side spin and face angle at impact, without any attachments to the club. The ten different putters were set to 2 degrees static loft (using a digital ‘Mitchell’ Loft and Lie Machine) and the shaft was clamped vertically in the robot. Twenty putts were recorded per putter condition with an impact ball speed of 6 mph ± 0.1. All putters had the grip removed (metal shaft clamped into the robot). Each ball was aligned with the manufacturer’s mark for the centre of the putter face for the horizontal axis (heel / toe) and in the middle for the vertical axis (top / bottom). The same ball was used for all tests. All putts were analysed using a straight back and straight through putting stroke. The robot was released using an electromagnetic release at the top of the backswing to control swing length and therefore impact speed. Any oscillations of the club head caused by the shaft were damped prior to release of the putter.

Figure 3: Quintic Ball Roll v4.4 Research Edition (1080 fps)

Figure 4: Putting robot in use.

Results

Summary / Findings:

• Robot testing shows a very small range in the clubhead parameters, for example Face Angle, Face Rotation, Path, Shaft Angle, Lie Angle, Attack Angle and Low Point. As you would expect the robot delivers each of the ten clubs in a very consistent manner.
• 6 of the 10 putters twisted open >0.1° as a result of impact.
• 4 of the 10 putters had minimal face twist <0.1° as a result of impact.
• Putter J had the largest face twist 0.28° opening as a result of impact despite being struck in the manufacturers centre line.
• The Putter’s ‘Face to Path Angle’ was effectively zero throughout the putting stroke given the putter was clamped into the robot. The resulting side spin ranged from +5 to -25 (30rpm) is due to ‘gear effect’ and the clubhead twist at impact.
• Impact Ratio (Ball Speed divided by Clubhead Speed) had a range of 0.18 (1.73 – 1.55)
• Therefore, in order to achieve a 6mph ball speed the clubhead speed ranged from 3.44mph to 3.89mph (A range of 0.45mph Clubhead Speed).
• Forward / Backspin had a range of 89rpm (-47rpm Back spin to +42rpm Forward spin)
• 6 of the 10 putters imparted backspin. The highest value is for Putter I with -47rpm.
• 4 of the 10 putters created forward spin. The highest value is for Putter G with +42rpm
• The point of forward rotation ranged from 0 to 4.72 inches.
• Despite all ten putters having 2 degree static loft and the same shaft angle (robot clamped vertically), the ball Launch Angle ranged from 0.47° to 3.12° (2.65°)
• As a result of inconsistent launch and spin, the distance to True Roll / Zero Skid ranged from 20 to 36 inches
• All ten ‘Ping Answer’ style putters had the same club parameters at impact (swing path, speed and acceleration profile) but the different putters produced significantly different ball impact parameters.

Practical applications

The best example of the above results are seen when a professional golfer changes manufacturer contracts. In many cases, the golfer loves and is used to playing with Manufacturer’s A model of putter. Despite Manufacturer B making an exact copy (dimensions, weight, colour, alignment guides, grip), the putter from Manufacturer B never performs the same. It is normally only a matter of time before the player reverts to the original model from Manufacturer A!

This is unsurprising, given the results of this study. The specifications of the putter, such as Total Weight, Swing Weight, Head Weight, Shaft as well as putter style will have an effect of the performance of the golf ball. This is due to the fact that ball speed, impact ratio, launch angle and spin can significantly change due to the different putter and shaft specifications. These parameters all affect the point of true roll, which then in turn effects ball speed and in particular how the ball breaks over the same 2 percent slope. Despite the player hitting identical putts (ball speed) the lines are different and they can’t explain why! The putter may look and feel the same but the golf ball reacts differently. The ball no longer matches what they are accustomed to seeing. The performance of the golf ball (which, at the end of the day, is what matters) can change significantly despite the same putter impact parameters.

When fitting a putter, the length, lie, loft and style may be the same, but unless you are measuring the ball speed, launch and spin, are you really fitting a putter correctly? I would always encourage a player to have their current ‘gamer’ measured using all the parameters within Quintic Ball Roll (both club and ball). Before any new putter is chosen, you must compare the two sets of numbers. You may well have you improved centre contact and putter face alignment, but by changing impact ratio, roll or launch angle for example you will alter the point of true roll.

You can’t predict what is going to happen at impact.
Quintic measures the golf ball.
Ball Speed, Launch and Spin are key!

Figure 5: Quintic Ball Roll v4.4 Research Edition – Composite Image (1080 fps)

Reference

Quintic (2019). Quintic Consultancy Limited, Unit 8, The Courtyard, Roman Way, Coleshill, Birmingham, B46 1HQ (UK) (www.quinticballroll.com)

Purpose

Many modern putters are marketed with movable weights, selling the idea of changing stroke parameters with minimal effort, for improving performance on the greens. Movable weights have been a huge success for driver manufacturers over the past few years. The putting stroke is much slower, so do movable weights have the same effect that they are perceived to be having with a putter? The following study investigates the effects on the club and ball impact parameters when moving weights (0-25 grams) around in the putter head in four different locations. How does moving weight around in the putter head affect the golf ball and club head during impact? There is very little research on moveable putter head weights. What are the practical applications for a putter with movable weights?

Methods

The Quintic Ball Roll v4.4 Research system (Quintic, 2019) uses a high speed camera (1080 fps) to measure factors such as ball speed, club speed, side spin and face angle at impact. The same putter head was used for each test. The putter had a factory weight of 366 grams, and a weight of 316 grams with the standard factory weights removed. The putter had four weight slots, front heel, front toe, back heel and back toe. See Figure 1.

Figure 1: Overhead view of the original factory set up of the weights and
the slots in the putter head.

The mass of the weight options ranged from 5 grams to 25 grams in 5 gram increments. The weights were moved around in all manors of specific permutations, with six generalised conditions; Relative heel weight, toe weight, frontal weighting, rear weighting, extreme weighting and the original factory weight condition.

A total of 72 different weight permutations were analysed using the putting robot. For each specific weight permutations, ten putts were recorded on the putting robot, each with an average ball speed of 6mph ± 0.2. The impact location was constant for each putt: middle (heel / toe) and middle (top / bottom). The average for all ten putts was then calculated per condition. The testing was conducted on an indoor artificial putting surface (Stimp 11). The initial testing was performed with a straight back and through putting stroke, followed by a 2 degree in-to-in putting stroke.

Figure 2: Putting robot in use.

Results

The first result was from the default manufacturer’s set up. This was then used as the control/comparison with the seventy two different weight permutations analysed. The following results were performed with a straight back and through putting stroke.

Figure 3: The original factory set up of the weights and the slots in the putter head (10_10_15_15).
Total Head Weight = 316g + 50g = 366g

Figure 4: Quintic Ball Roll summary (n=30) for default manufacturer’s factory set up (10_10_15_15).

Total Head Weight

Throughout all the tests the total head weight, regardless of the individual weight locations is reported below and then ranked in ascending order.

Table 1: Showing the increase in Impact Ratio (IR) as the head weight increases
from the 316g (no weight condition (0_0_0_0).

Increasing the total head weight in the putter head increases the impact ratio, (≤30g 1.68 vs >60g 1.73) The Impact Ratio (IR) is the ball speed divided by club speed. IR relates to the amount of energy transferred from the putter head to the golf ball during contact. The higher the impact ratio, the higher the energy transfer. Increasing the head weight increases the energy transferred to the golf ball. The highest IR was recorded with the 90g weight combination (IR 1.75) (90g represents a 28.48% increase in head weight). The lowest IR was recorded with the 0g weight combination (IR 1.67).

Frontal weighting

These results were drawn from adding six even sets of weights to the front of the head (Slots 1 & 2) in 10g increments from 0g to 50g. The six conditions analysed were as follows:

Figure 5: Frontal Weighting (Pairs Front) (0_0_15_15).

Table 2: Shaft angle, Launch angle, Attack angle, Forward rotation
and Side spin, as frontal weight increases in putter head location.

Changing the weighting on the front of the putter only had, the following noticeable differences. Firstly, as the weight increased towards the front, the attack angle increased from -0.40° to 0.38°. As the attack angle increases, so does the shaft angle 0.08° to 0.24° and launch angle of ball from 2.02° to 2.67°. As a result of an increased launch angle, the distance until the start of forwards rotation also increased from 2.28 inches to 3.45 inches. The average hook spin on the ball also increased as the weight moved towards the front of the putter, although the hook spin remained relatively low. Despite the changes in shaft, launch and attack angle of the putter it was interesting to note that the backspin (rpm) of the golf ball remained consistent throughout all six weighting conditions (-40rpm ± 4).

Rear weighting

These results were drawn from adding even sets of weights to the rear of the head (Slots 3 & 4) in 10gr increments from 10g to 50g. The six conditions analysed were as follows:

Figure 6: Rear Weighting (Pairs Back) (15_15_0_0).

Table 3: Shaft angle, Launch angle, Attack angle, Forward rotation
and Side spin, as rear weight increases in putter head location.

Weighting at the rear of the club made minimal differences to the shaft, launch and attack angles. The balls performance, notably the point of forward rotation and backspin showed little differences. Furthermore, hook spin remained almost identical for the six weighting conditions.

Heel weighting

These results were compiled of many different weighting configuration tests in the heel and then split into above and below 25g combined weighting in the heel. (Slots 1 & 3). Slots 2 (10g) and 4 (15g) were as per the factory setting throughout the heel weighting tests.

Table 4: Side spin (rpm) and the effect of heel weighting.

When weighting the heel the only results that differed from the factory data (along with total weight data that is already reported) was the increase in the hook spin created on the golf ball. As more weight is added to the heel the hook spin increased (≤25g -7.09rpm vs >25g -12.92rpm). This is potentially due to the face twist created during impact and a change in the centre of mass of the putter. The default factory set up had on average -12rpm of hook spin.

Figure 8: Quintic Ball Roll graphical representation of ball spin (Forward/Back, Side, Rifle)
and total spin rpm and spin axis (Tilt, Rotation)

Toe weighting

These results were compiled of many different weighting tests in the toe and then split into above and below 25g combined weighting in the toe. (Slots 2 & 4). Slots 1 (10g) and 3 (15g) were as per the factory setting throughout the toe weighting tests.

Table 5: Side spin (rpm) and the effect of toe weighting.

When weighting the toe, the only results that differed from the factory data and the total weight data, was the sidespin. Sidespin was similar as an average, however, when weight was increased, the amount of hook spin decreased (≤25g -11.11 rpm vs > 25g -8.97). This is most likely due to the face twist after impact due to there being more mass on the one side of the head and a change in location of the centre of mass of the putter. 45g of weight in the toe resulted in +1 rpm of cut spin. The default factory set up had on average -12rpm of hook spin.

Figure 10: Quintic Ball Roll graphical representation of ball spin (Forward/Back, Side, Rifle)
and total spin rpm and spin axis (Tilt, Rotation)

Extreme weighting

In this part of the test, a single maximum 25g weight was put into each slot alone and tested in the same manner. This test was aimed at establishing each weight slot’s effect individually. The 25g weight increased the total head weight to 316g + 25g = 341g (7.91% head weight increase)

Figure 11: Extreme Weighting (25g in each of the four slots)

Table 6: Table showing the effect of placing 1 x 25g weight in each of the four slots.

When extreme weighting the 4 slots on the putter head, there was only one clear difference between each slot compared to each other and the factory setting. The differences between each slot were virtually nil; however, there was a significant difference in side spin between when the weight was in a heel slots (1 & 3) compared to when in the toe slots (2 & 4). When in the heel slots, the average hook spin was -14rpm (Slot 1) and -13rpm (Slot 3), however when in the toe it reduced to -5 rpm (Slot 2) and -2 rpm (Slot 4). In some individual putts, the spin impacted on the ball was a slight cut spin +ve value for Slot 4.

Effect of Putter Path – ‘Straight Back and Through’ vs ‘3 degree in-to-in Arc’

Figure 12: The original factory set up of the weights and the slots in the putter head (10_10_15_15).
Total Weight = 316g + 50g = 366g

Table 7: Table showing the effect of Path for the Factory Setting (10_10_15_15)
(30 putts per condition)

The effect of 2° ‘in-to-in’ putter path had no difference on the factory setting weight condition (n = 30 putts)

Figure 13: Quintic Ball Roll : Robot Path Summary graph of the two path conditions for the Factory Setting.
Straight back and through (Red) and the 2 degree in-to-in arc (Blue)

Swing Weight

Swing weight, in essence, is the relationship between the weight in the bottom two thirds of the club and the top third of the club. From the perspective of the player, it simply means how the club feels through the swing and impact (heavy or light, etc.).

The swing weight of all the 72 weight combinations from smallest to largest were measured using a swing weight scale, and then ranked alongside total weight addition.

Table 8: Table showing the change in swing weight based on the
amount of weight added to the head of the putter

The original head weight with no weights in is 316 grams, with a 28.48% increase (90g) the swing weight changes from C7 to F4 (37 different swing weights!). This is a large difference; moving weights in the club head to potentially solve a stroke issue will subsequently change the swing weight, feel of the putter and the launch characteristics of the golf ball.

Face balance test

Changing the weights in the putter also affected the face balance/toe hang. Maximum weight (50g) was added to the heel and toe and compared to the factory settings to see the differences.

Factory

(Small Toe hang ≈ 4°) (10_10_15_15)

Figure 14: Graphics showing face balance of the putter in factory weight setting.

Toe

(Relatively large toe hang 18°) (0_25_0_25)

Figure 15: Graphics showing face balance of the putter, with the maximum weight in the toe.

Heel

(Slight toe up, -3° toe up / 3° heel down) (25_0_25_0)

Figure 16: Graphics showing face balance of the putter with the maximum weight in the heel.

Between maximum toe and maximum heel weighting of the putter head, there was a range of 21° in the face hang, hanging more toe down when the toe was weighted and more toe up when the heel was weighted.

Summary / Findings:

• Increasing total weight in the putter head will increase the impact ratio
• Weight in the front of a putter will increase the shaft, launch and attack angle, as well as increasing the point of forward rotation and side spin.
• Rear weighting has minimal effect on ball’s performance or putter impact
• Weighting the heel of the putter causes an increase in hook spin
• Weighting the toe causes a decrease in hook spin
• Weight in the heel causes slight toe up / face balance
• Weight in toe causes significant increase in the amount of ‘toe hang’
• The 2° ‘in-to-in’ putter path had no effect on the factory setting weight condition (n = 30 putts)

Practical applications

Before now, the actual effect of movable weights in a putter head were relatively unknown. This study highlights the effect of moving weights in to different locations of the putter and the result changes measured in the balls launch parameters. In real-life terms, this could be used for several things, for example putter fitting. When someone is fitted for a putter using Quintic Ball Roll, or any other putter measuring device, if a particular person has trouble with high hook spin, then results from this study would suggest that a weighted toe will decrease the hook spin created, all without the player feeling they are changing their stroke or technique. In addition to this, we now know that changing weights effects the amount of toe hang, the swing weight of the putter and potentially even the launch angle of the ball. The overall head weight of a putter is important for the individual. Too light or too heavy and it becomes difficult to square the face consistently at impact.

This information potentially can be applied when somebody is having issues with their stroke, enabling them to feel a difference in their stoke, without having to have a lesson or even change their putter.

Future research

This research was carried out on a mallet putter with four weight slots. It would be interesting to carry out a very similar study with similar parameters but on a bladed putter with movable weights as research has shown that bladed putters react differently to mallet putters.

Reference

Quintic (2019). Quintic Consultancy Limited, Unit 8, The Courtyard, Roman Way, Coleshill, Birmingham, B46 1HQ (UK) (www.quinticballroll.com)

2018 WORLD SCIENTIFIC CONGRESS OF GOLF
July 11-13, 2018   Abbotsford, BC Canada
Host: University of The Fraser Valley

Purpose                                                       

A putt hit with the perfect line but with the wrong speed might still miss the hole due to how the ball slows down and reacts with the terrain of the putting green. The following study investigated the significance of impact location for nine leading club designs (See ‘Putter Specifications’) including three blade style, three mallet style and three marketed as having a high moment of inertia (MOI). How does a different impact location on the putter face affectball speed and does the style of putter have any influence? Ball speed has a significant effect on putting results and should be considered an important factor when putting at any level (Pelz, 2000). Despite this, the ability to control ball speed can often be overlooked in coaching. Ball speed is one of the four reasons as to why a putt might miss (Cochran & Stobbs, 2005).

Figure 1: The effects of ± 50 percent errors in the initial trajectory (left) compared to the effects of only ± 10 percent errors in the putt speed (right). Dewhurst (The Science of the Perfect Swing, 2015, Oxford University Press). “Speed is more important than target line” (Dewhurst, 2015).

The ability to control the speed of the putter head with controlled face aim, along with green reading, are all a primary determinant of putting consistency (Karlsen et al.2008). However, little or no focus is aimed towards the effect of ball speed as a result of the design of the putter or even the club face material. The purpose of the study was to better understand the role of impact location and club design on the ability to control ball speed and ultimately control distance.

Methods

The Quintic Ball Roll system (Quintic 2016) uses a high speed camera (360 fps) to measure a variety of factors including clubhead speed, ball speed, face angle, face rotation and putter twist as a result of impact. Nine different putter designs were used for the study (three blade, three mallet and three high MOI design putters). Nine impact locations were analysed per putter (see Figure 2 below).

Figure 2: 9 Impact Locations

Locations 2, 5, and 8 were determined by the manufacturer’s markings indicating the centre alignment guide on the putter.  The toe and heel points are two centimetres either side of the midline. Points 4, 5 and 6 are in the middle of the face (top / bottom). The top and bottom rows were equally spaced out, depending on putter face depth or the insert depth (see Figure 3).

Figure 3: A visual representation of the impact location (top / middle / bottom)

Ten putts were recorded and analysed for each impact location reproduced by the putting robot (Figure 4). The clubhead was released from the same location for each putter on a straight back and straight through path. The protocol was conducted on an indoor artificial putting surface (Stimp 11). Clubhead and ball speed, face angle at impact and putter twist were recorded for the nine impact locations per putter design, using the Quintic Ball Roll system.

Figure 4: Average club head speed = 3.65mph ± 0.04 for each putt reproduced by the putting robot. The clubhead was released from the same location for each putter.

Results

The first part of the study was to investigate the impact ratio for a centre strike (impact location 5 – Centre, Centre) for all nine putters. The results can be seen in Table 1. Impact Ratio (Ball Speed / Clubhead Speed) ranged from 1.62 to 1.72.

Impact Location 5:The Impact Ratio (IR) is the ball speed divided by club speed. IR relates to the amount of energy transferred from the putter head to the golf ball during contact. The higher the impact ratio, the higher the energy transfer (the ‘hotter’ the putter face). The IR ranged from 1.62 to 1.72 for location 5 (impact centre / centre) for the nine putters. Thisvariation in ball speed, caused by a variation in IR, will cause the ball to travel different distances and therefore slow down at different rates, particularly relevant to the golfer on sloping putts.

A ball speed range of 0.47 mph was reported between the nine different putters for centre impact, despite the clubhead speed at impact having a range of 0.13 mph (3.59 to 3.72 mph. These differences are caused by the variance in material, head weight and design of the putter). The high MOI putters had on average a higher head weight of 365gms ±6. The blade style putters had the lowest head weight of 351gms ±2 (see ‘Putter Specifications’)

9 Impact Locations:  Centre, centre (Location 5) was always the highest IR for all nine putters. PING Vault Oslohad the highest IR of 1.72, with the lowest value being 1.46 (Low, Heel) for the TaylorMade Spider Red.

Table 2: PING Vault Oslo – Mallet   Impact Ratio (IR) and % drop for the 9 Impact locations
0% = Centre, Centre impact location 5.   % reduction in IR depending on Impact location (1-9).

Table 3 : TaylorMade Spider Red – MOI   Impact Ratio (IR) and % drop for the 9 Impact locations.
0% = Centre, Centre impact location 5.  % reduction in IR depending on Impact location (1-9).

If both putters had an average clubhead impact speed of 3.65mph, this would equate to a 0.95mph difference in ball speed (3.65mph  x 1.72 (IR) = 6.28mph PING Vault Oslo : 3.65mph x 1.46 (IR) = 5.33mph Taylor Made Spider Red). How does this equate to ball roll out distance on the actual putting green?

Table 4 below highlights the initial ball speed in both feet per second and miles per hour for a flat (no wind or grain) putting green stimping at 8, 9, 10, 11 and 12 respectively. Rows 8 ft/sec (5.45 mph) and 9 ft/sec (6.14 mph) are highlighted in red, as they represent the closest ball speed readings for the Taylor Made Spider Red (5.33mph) and PING Vault Oslo (6.28 mph).

Table 4: Ball Speed (ft/sec) (mph) total roll out distance (feet) on a flat green, no grain or wind) for the respective Stimp readings. Data provided courtesy of Aim Point.

• Stimp reading of 8, there is a difference in ball roll out distance (16.1 – 13.2) = 2.9ft
• Stimp reading of 9, there is a difference in ball roll out distance (18.1 – 14.9) = 3.2ft
• Stimp reading of 10, there is a difference in ball roll out distance (20.1 – 16.5) = 3.6ft
• Stimp reading of 11, there is a difference in ball roll out distance (22.1 – 18.2) = 3.9ft
• Stimp reading of 12, there is a difference in ball roll out distance (24.1 – 19.9) = 4.2ft

A 4.2ft difference in roll out ball distance (Stimp 12) of a putt travelling 24.1ft highlights the importance of IR (and putter specific designs) along with the impact location on the actual face. These differences in roll out distance will only increase as the putt is hit harder…

Discussion

There is a perceived notion that blade putters have the least amount of drop in ball speed with miss hits, but a greater horizontal dispersion. In contrast, high MOI putters are designed to reduce the horizontal dispersion, but as a consequence there is a lower ball speed from miss hits. The results from this study show that every putter is different. The MOI putters recorded the highest percentage drop in ball speedfor miss hits in location 4 and 6 (across the centre line, toe to heel). Evnroll ER2 – Blade had the lowest drop (2%) across the midline (impact location points 4, 5 and 6).

As a general observation, impact location points 2,5,8 (high / low) and 4,5,6 (across the face) have the least drop in energy transfer (impact ratio) across all nine putters. Low on the putter face (impact location points 7,8,9) have the largest drop, with low heel (impact location 9) having on average a drop of 10%.One particular blade putter (Bettinardi BB1F – Blade) had a 14% drop for impact location 9.  Evnroll ER7 – MOIhad the lowest drop (8%) between impact location 5 and 9 (Low Heel). 

Practical Application

Golfers need to be able to consistently control ball speed in order to achieve a consistent end distance. Impact ball speed is directly affected by the impact club head speed. However, head weight, face technology and impact location collectively all have an influence on the IR. Inconsistencies in impact location will cause an inconsistency in the impact ball speed. A consistent strike point is required for a consistent impact ratio regardless of head weight or face technology.

“If you can’t hit it consistently out of the middle, how do you expect to start the ball on your intended line, with the correct pace”
Danny Willett   (Masters 2016 Champion) 

“Most three putts aren’t caused by bad green reading, but by bad judgement of speed”
Ben Crenshaw (Masters 1984, 1995 Champion)

During this study we saw a potential difference of 3.6ft ball roll out distance (16-20 ft putts on 10 stimp greens) with a clubhead speed of only 3.65mph, based solely on impact location and putter design.

A high IR will cause any variations in impact club head speed to be magnified, however, the speed the ball reacts from the putter face is often a personal preference and one the player often becomes accustomed to. If a new face insert is introduced, or even model style this may well result in a new IR. As a result this will affect the resultant ball speed and will require adjustment fromthe player on the putting green. Every putter is different and not every high MOI putter necessarily performs better than a blade putter on an off centre hit. This ultimately requires a player to measure any potential new putter and compare its characteristics to their current putter.

• The IR is the ball speed divided by club speed.
• IR relates to the amount of energy transferred from the putter head to the golf ball during contact.
• Impact clubhead speed has the greatest effect on impact ball speed, but IR will also influence this.
• Normally the consistency of the IR is more important than the average.
• However, a high IR will cause greater variations in the impact ball speed.
• IR is affected by the head weight, face technology (inserts, grooves, milling) and impact location.
• Not every high MOI putter necessarily performs better than a blade for off centre hits.

An area for further research is that relating to clubhead twist and the effect this has not only of IR but also the horizontal start direction. During the study, it was noticeable that the different impact locations and models react differently in terms of IR, hence different ball speeds, but also increased variations in horizontal start direction. This is an area of further investigation, involving over head cameras to quantify the exact start direction. In addition to horizontal start direction, the influence on vertical ball launch caused by high and low strikes on the clubface is also an area of further investigation.

References

• Cochran, A. J. & Stobbs, J. (2005). Search for the Perfect Swing. Chicago: Triumph Books.
• Pelz, D. (2000). Dave Pelz’s Putting Bible: The Complete Guide to Mastering the Green. New York:
• Karlsen, J., Smith, G, Nilsson, J (2008). The stroke has only a minor influence on direction consistency in golf putting among elite players. Journal of Sports Science, February 1^st2008; 26(3): 243-250
• Quintic (2016). Quintic Consultancy Limited, 160 Lichfield Road, Sutton Coldfield, B74 2TZ (UK) (quinticballroll.com)
• Dewhurst, P. (2015). The Science of the Perfect Swing. Oxford: Oxford University Press.
• Donaldson, J. (2013, March). Green Reading: Need for correct speed. Aimpoint Golf.(https://aimpointgolf.com/)

Putter Specifications:

^{Table (I) : Odyssey O Works #1 Wide – Blade   Impact Ratio (IR) and % drop for the 9 Impact locations
0% = Centre, Centre impact location 5.  % reduction in IR depending on Impact location (1-9).}

Head type: blade / Loft: 3° /  Lie: 70° / Hosel: S-neck / Offset: ¾ shaft / Toe hang: 47° / Head weight: 350g
Advertised features: Microhinge technology provides incredible gains in topspin and roll at impact regardless of the stroke. The stainless steel Microhinge plate is co-moulded into our Thermoplastic Elastomer Feel Layer, providing great feel and getting the ball into a better roll at impact. The new mallets with toe hang are all designed for players who like to feel the face of their putter rotate more in their stroke.

Table (II) : Bettinardi BB1F – Blade   Impact Ratio (IR) and % drop for the 9 Impact locations
^{0% = Centre, Centre impact location 5.  % reduction in IR depending on Impact location (1-9).}

Head type: “Anser 2” / Loft: 3° / Lie: 70° Hosel type: long plumbers neck / Offset: ½ shaft / Toe hang: Strong / Head weight: 350g
Advertised features: The BB1, our classic blade-style putter, has received unique cosmetic and performance upgrades for 2018 which includes a neck that has been moved slightly forward towards the sweet spot which promotes less toe hang. The traditional Honeycomb face has been replaced in favour of our aggressive fly mill milling technique, which produces a softer feel at impact. A new Stealth Black finish is complimented with an electric yellow paint scheme, reducing glare and improving aim optics.

Table (III) : Evnroll ER2– Blade   Impact Ratio (IR) and % drop for the 9 Impact locations
^{0% = Centre, Centre impact location 5.  % reduction in IR depending on Impact location (1-9).}

Head type: blade / Loft: 3° / Lie: 70° / Hosel type: Single bend / Offset: ½ shaft / Toe hang: Slight / Head weight: 355g
Advertised features: This precise face milling imparts progressively to provide more energy transfer on off-centre putts.This improves distance control to prevent you coming up short on off centre putts. This milling pattern also gears the ball back to the centre, so you hit the sweet spot of the putter for greater consistency.

Table (IV) : Odyssey O Works R Line – Mallet   Impact Ratio (IR) and % drop for the 9 Impact locations
^{0% = Centre, Centre impact location 5.  % reduction in IR depending on Impact location (1-9).}

Head type: mallet / Loft: 3° / Lie: 70°/ Hosel type: Long Hozel / Offset: ½ shaft / Toe hang: Face balanced / Head weight: 350g Advertised features: Our Microhinge Insert Technology provides incredible gains in topspin and roll at impact regardless of your stroke. The stainless steel Microhinge plate is co-moulded into our Thermoplastic Elastomer Feel Layer, providing great feel and the new geometry of the hinges and urethane together help to get the ball into a better roll at impact.

Table (V) : Taylor Made TP Berwick – Mallet   Impact Ratio (IR) and % drop for the 9 Impact locations
^{0% = Centre, Centre impact location 5.  % reduction in IR depending on Impact location (1-9).}

Head type: mallet / Loft: 3° / Lie: 70° / Hosel type: plumbers neck / Offset: ½ offset / Toe hang: face balanced / Head weight: 350g Advertised features: The Berwick putter is perfect for golfers who prefer a face-balanced, mallet style putter with a sleek profile. Created in a precise, rounded shape, this putter includes a single sightline on the back cavity. Complete with a double bend shaft and full shaft offset, this putter provides a straight back, straight through putter stroke. The putter has a new and improved pure insert roll for a better roll, and has adjustable sole weights to set the up the putter for your perfect playable swing weight. To help you stay on track and sink more puts the putter has two sightlines and has Tour validated putter grip to give you maximum feel and touch.

Table (VI) : PING Vault Oslo – Mallet   Impact Ratio (IR) and % drop for the 9 Impact locations
^{0% = Centre, Centre impact location 5.  % reduction in IR depending on Impact location (1-9).}

Head type: mallet / Loft: 3° / Lie: 70° / Hosel type: single bend / Offset: no offset / Toe hang: face balanced / Head weight: 365g Advertised features: a smaller mallet with geometric features to frame the ball at address, including a low level sightline. The Vault Oslo features a new True Roll (TR) face technology. This technology uses face grooves that are machined to varying depths to help speed up off-center hits and provide more consistency in your putts. A stainless steel bottom weighting boosts MOI and lowers CG to improve your putting performance.

Table (VII) : Evnroll ER7 – MOI   Impact Ratio (IR) and % drop for the 9 Impact locations
^{0% = Centre, Centre impact location 5.  % reduction in IR depending on Impact location (1-9).}

Head type: mallet / Loft: 3°/ Lie: 70° / Hosel type: single bend / Offset: ½ offset / Toe hang: Slight / Head weight: 370g
Advertised features: This precise face milling imparts progressively to provide more energy transfer on off-centre putts. This improves distance control to prevent you coming up short on off centre putts. This milling pattern also gears the ball back to the centre, so you hit the sweet spot of the putter for greater consistency.

Table (VIII) : TaylorMade Spider Red – MOI   Impact Ratio (IR) and % drop for the 9 Impact locations
^{0% = Centre, Centre impact location 5.  % reduction in IR depending on Impact location (1-9).}

Head type: mallet / Loft: 3° / Lie: 70° / Hosel type: long plumbers neck / Offset: ½ shaft / Toe hang: Moderate (38°) / Head weight: 355g Advertised features: High MOI for increased forgiveness and stability. Smooth crown, no sightline, and short slant neck hozel for Spider Tour Red and Spider Tour Black. Long sightline, double bend shaft and face balanced head for Spider Tour Platinum. Spider Tour Red has a Pure Roll Surlyn insert for softer sound and feel. Spider Tour Black has a Pure Roll 80/20 insert for firmer sound and feel. Vibration-dampening foam for consistent sound and feel.

Table (IX) : Ping Sigma G Wolverine T– MOI   Impact Ratio (IR) and % drop for the 9 Impact locations
^{0% = Centre, Centre impact location 5.  % reduction in IR depending on Impact location (1-9).}

Head type: mallet / Loft: 3° / Lie: 70° / Hosel type: double bend / Offset: ½ shaft / Toe hang: face balanced / Head weight: 370g Advertised features: A high-energy Pebax elastomer insert behind the anodized 6061 aluminium face provides a soft feel without slowing ball speed, ensuring full-face forgiveness and consistent distance control. True Roll Face Technology supplements putting touch for improved consistency and fewer three-putts.

Introduction:

Mohammed Hafeez  (MH) was reported for a suspected action after the third ODI against Sri Lanka in Abu Dhabi in October 2017 and underwent his ICC Independent Assessment in Loughborough (November 2017).  The results highlight on average an 18.5˚ elbow extension ‘over the wicket’ (OTW) and 15.2˚ elbow extension ‘around the wicket’ (ATW).  Three of the 24 deliveries analysed reported elbow extension below the permitted 15˚ extension. The highest record value was 22˚ elbow extension. In order to return to International Cricket, the key objective is to enable MH to bowl within the ICC tolerance of 15˚ extension. A second objective is for MH to continue to be effective in his bowling and remain the world’s top-ranked ODI all-rounder.

First Stage:
Prior to his visit to the UK it was important that we understood MH’s typical bowling action; this included looking at whether his action had changed over time due to previous ICC action reviews. Footage from multiple matches was reviewed, aiming to identify MH’s bowling tendencies, focusing on his body position and how the position which he took up could result in compensation with flexion at the elbow. A key question to answer and explain related to the Elbow Angle at Upper Arm Horizontal   (Loughborough – Nov 17) – Average 23˚ Maximum 24˚. This is very different to the ICC Independent Assessment (Brisbane – Nov 16) – Average 5˚ with a maximum Elbow Angle at Upper Arm  Horizontal of 9˚. Why the difference?  This was a key area to review and understand why the changes.

Second Stage:

Once Hafeez arrived at the Quintic office, our findings from match footage review and the ICC report were discussed in detail. Our biomechanical observations and recommendations were discussed with Hafeez, Carl Crowe and Azhar Mahmood. This included talking through why Hafeez has the tendency to produce flexion at the elbow. Also discussed were the changes that could be made at a whole body level to reduce the need for this elbow flexion, this progressed into the plan of action. Some of the adjustments could be made over the course of a few days, whereas others needed to be drilled and continuously worked on over the following few months, with successful completion this would then result in a desirable and legal bowling action. The biomechanical changes involved feet positioning, hip rotation and torso alignment with the aim to reducing the need for flexion / extension movement at the elbow.

Summary of Technical Questions (Pre Indoor School Bowling / Drills):

Two areas to focus: Legality & 15 degree Elbow Extension / Efficiency Improve Bowling Performance

Legality:

• How to make up the approximate 10-15% of ball speed that currently would be as a result of the elbow extension being greater than 15 degrees. For the elbow to be legal, then speed / revolutions need to be increased from other body parts, notably, wrist, shoulder, torso, hips, lower body…
• Rotation of bowling arm, lower body working more efficiently, driving from back leg, up and over the front leg, Point of release (higher point of release, wider / higher)
• Length of Run up – Shoulders Square Side on Action? Up and over front leg? Length of delivery stride.
• Release Pattern? How does MH impart spin on the ball?

Efficiency of Bowling Action:

• Scrambled seam / change of pace / point on the crease / grip
• Size of hands? Wrist movement, how fast can you move your wrists
• Revolutions on the ball? Not a big spinner? Up the back of the ball? Wrist position and release pattern?
• Type of varieties? Top / Traditional Off Spin?
• Match effective due to experience and being a batsmen.
• Hip Drive- 45 degree foot at BFC
• Height of release.
• Good alignment with feet to starting direction of the ball.

Third Stage:

Whilst MH began going through the drills in the UK, all movements were recorded using Quintic high speed cameras so that the footage could be quickly reviewed. This allowed MH (and the coaching team) to gain a better understanding of how his body was moving during the bowling action. After each drill was complete, the video footage was reviewed, with improvements and weaknesses being identified and discussed; what is causing this weakness and how can it be worked on. A large number of drills were completed during this time as we progressed from functional movements to more game and action specific training. Video footage was continuously reviewed with areas of weakness identified, discussed and worked on in a progressive manner. Some of these drills were categorised as ongoing and would have to be worked on by Hafeez over the following months, if a permanent change in action were to result.

Fourth Stage:

Three high-speed Quintic cameras were set up along with 3D reflective body markers used to asses MH bowling action. The analysis was completed shortly after completing all the drills and technical changes were fresh in MH mind. Match style bowling was performed, along with one step and two step run ups. All footage could also be reviewed by MH after each delivery and alterations could be made between each delivery if required. Many deliveries were completed and analysed using this set up. After the completion of data collection, we proceeded to create a 3D report, indicating where the legality of his action. This gave MH something clear to work on, as he prepared for his ICC assessment in Loughborough.

Ongoing Work and Analysis:

During the months after the work at Edgbaston, constant work by the team, (Carl, Azhar and Dr Paul Hurrion) was necessary to ensure the technical changes required were adhered too. It was imperative the bowling action became natural, flowed and second nature to MH. Videos, email, phone conversations ensured the team where all keep up to date and most importantly MH was completing his drills effectively and gaining confidence.

Only when the team were happy with MH bowling action, was he recommended to go for the ICC re-assessment. The aim now following the success outcome of the ICC test, is to ensure the MH is never called again for a suspect action, with the aim to make him an even more effective ODI spin bowler at International level.

          Dr Paul, D, Hurrion

The proximity a ball finishes to the hole and strokes gained putting are two common statistics measured on the PGA Tour. Strokes Gained Putting quantifies a golfer’s putting performance relative to the field, taking into account the initial distance of each putt. Therefore, holing a 10ft putt scores higher than holing a 5ft putt. However, how many times do you hear a commentator say, “They have left themselves a tricky putt here?” When faced with certain putts during a round of golf, why do some putts feel easier than others, even though the putt may be longer?

I can find an 8ft putt that most players of a single figure handicap would be disappointed if they missed and yet I can find another 8ft putt that the chance of even the best players in the world holing is 10% at best – why is this? Proximity to hole is certainly a contributing factor for success rate, however, the following drill I have designed is to highlight that this is not always the case. I have called it the ‘Snowman Drill’ – hopefully, once you have completed the drill the name will be self explanatory! The drill will highlight your strengths and weaknesses on the putting green.

Set-up Instructions:

Find a uniform slope (or as close as possible) on the putting green (between 2 and 3% being ideal). Spend a couple of minutes to find the true down slope (12 o’clock) and the true upslope (6 o’clock). This is a skill in itself and one I very much encourage a player to learn. It can save a lot of heartache in the future!  If you have a PH String Line then it is always a good idea to run the string up and down the fall line. (Please remember if you can’t find a uniform slope, the true upslope and true down slope might not necessarily be the same, so you may need to slightly offset your clock face). You can always use a PH Ghost Hole if it makes it easier to find a uniform slope.

Place twelve tees in the ground at the ‘12 clock face’ locations, each 12ft from the hole. This is always your starting point. The aim of the drill is to hole two consecutive putts at the furthest distance possible for each location. For the first attempt please start from the 1 o’clock location. If you miss a putt, then you move 1 foot closer to the hole on the same line. Now you must try and hole 2 consecutive putts from 11ft and so on until you manage to achieve 2 consecutive putts from the same distance. If, for example, this is at 6ft, mark it on the chart (please see below to download the ‘Snowman Drill’), enter the distance in the table and move on to 3 o’clock, starting again at 12ft.  Please ensure you go through your routine for each putt, and don’t rush…

Snowman Drill, I would advise starting from 1 o’clock and then moving to 3, 5, 7 ,9, 11, and then round again starting from 2, 4, 6, 8, 10 and 12 o’clock.

• What distance did you manage to hole 2 consecutive putts from each of the positions on the clock face?
• Once you have completed the task and filled in the table, join the dots together on the chart.
• Do you see a pattern or picture developing?
• Do you hole more putts right-to-left or left-to-right?
• Or uphill or downhill?
• Which position on the clock face gives you the largest distance for conversion of the putts?
• Which position on the clock face gives you the shortest distance for conversion of the putts?

This drill is a way to identify your strengths and weaknesses along with identifying your safe zone! If your ball finishes inside your safe zone, you should be very confident in holing the putt, and you have the right to be upset with yourself for missing the putt. If you had a putt of 6 feet, where would you prefer the putt to be to maximise your chances of success?

Please see the two completed drills from a PGA European Tour Player and one from a 7 handicap male golfer. What are their strengths and weakness? Which position on the clock face gives the player the largest and shortest distance for conversion of the putts? Compare the size of their safe zones’.

PGA European Tour Player

7 Handicap Amateur

Next time you are playing your bunker shot or chip from a poor lie, work out where your true down slope is (6 or 12 o’clock), where your safe zone is and try and ensure your ball finishes inside it. If that means playing slightly away from the flag then so be it. There is nothing worse than playing a good bunker shot to 6ft (the crowd give you a clap), only to be left with a putt outside your safe zone! Of course you can still hole this putt, but it is a significantly harder putt than one of the same 6ft length that is inside your safe zone! Why? Because, you have completed the snowman drill and know your own strengths and weaknesses. There will obviously be the occasions during match play events when a chip in is required to make the cut, or even a holed bunker shot is the only way to force a play-off. Your strategy will be more aggressive as a result, but golf is predominately played over a medal format (over four days) when playing the percentages (playing to your safe zone) is often required to ensure you shoot the lowest score possible. There is a time and a place to be aggressive, for me understanding your strengths and weaknesses are crucial to success.

Typically clock face positions 2 and 10 are the hardest, because you have a smaller margin for error with ball speed in these starting positions. Ball speed is not only influenced by clubhead speed at impact, but also clubhead acceleration during impact, impact location, ball launch angle, ball spin and, ultimately, the point of true roll. As a result you can’t chose the line you want to hit your putt on until you have decided on the speed you wish to hit the putt. Speed determines the line, the point of true roll and, ultimately, how a golf ball slows down determines where the ball will take the break of the slope. A number of playing professionals have completed this drill and nobody has a uniform distance over all twelve clock face locations! In fact some vary in distance by over 5ft, highlighting to the player that indeed, not all putts of the same length are equal. I would encourage any aspiring golfer, to understand their strengths and weaknesses and ultimately what their safe zone is by trying the Snowman Drill.

Summary:

1) Find the straight putt, both uphill and downhill.

2) Play the simplest possible shot to leave yourself inside your safe zone allowing you the easiest putt.

3) Turn three putts into two putts by playing the percentages to leave yourself inside your safe zone.

4) Increase your up and down percentages by playing sensibly and ensuring your approach shot finishes in your safe zone.

5) Make more birdies from 100 yards and in, giving yourself the easier birdie putt inside your safe zone, despite being further away, you will have a higher chance of success.

6) If you are a playing professional, I would ask you to complete the drill using three balls! You must hole three consecutive putts for each clock face position. How does the safe zone compare to two balls?

Pace putting from 30ft to leave yourself inside your safe zone

If you would like to be included in my on going research into this area, please send me your
completed Snowman Drill Chart. I would be most grateful for your data.
Many thanks, Paul    (info@paulhurrion.com)

 Speed Changes Everything – an investigation into the effect of launch
characteristics on putting performance

          Dr Paul, D, Hurrion., James, MacKay., Mark, Sweeney., Mr Andrew, R, Collinson

Purpose

A putt hit with the perfect line and initial start speed might still miss the hole due to varying amounts of skid, roll and launch angle. The following study investigated the variation of launch characteristics during putting to determine how these differences affect the outcome of ball speed. Speed has a significant effect on putting results and should be considered an important factor when putting at any level (Pelz, 2000). Despite this, the ability to control ball speed can often be overlooked and focus in coaching and performance predominantly aims to control the speed of the putter head. Aim and green reading are the primary determinant of putting direction consistency (Karlsen et al. 2008), however little or no focus is aimed towards ‘clubhead twist’, centre contact or even the launch characteristics of the golf ball. The purpose of the study was to better understand a player’s ability to control ball speed and distance control, despite their normal variability in putter head speed by changing launch and spin conditions.

Method

The Quintic Ball Roll system uses a high speed camera (360fps) to measure a variety of factors including ball speed, roll, spin, launch and skid during the first 16 inches of a putt. Ten putts were performed by an elite professional (Top 60 World golf Rankings – Sept 2015) outside on a flat green (0% slope; Stimp 11). The putt distance was 12ft and each putt was recorded individually using the Quintic Ball Roll system. Speed control of the participant was paramount, therefore the participant selected is widely considered to be one of the best ‘pace putters’ in the world. The data collected by Quintic Ball Roll was mathematically modelled using AimPoint software, a green reading tool that helps to understand break speed and aim by assuming true roll over the entire length of the putt. All 10 putts were simulated across different angles (12 angles around the clock face over 30 degree increments) and three different slope percentages (1%, 2% and 3%) to determine the outcome of the ball. The modelling used a surface stimping at 11.

Analysis/Results

Table 1 shows the raw data collected for each of the ten putts on the flat surface. The range in ball speed at 0 inches was 0.28 mph (5% variance from the mean) and this increased to 0.41 mph at 16 inches (14% variance from the mean). Due to differences in launch angle, roll and skid, this equates to a further difference of 0.56 mph between the fastest and the slowest putt by the time the golf ball reached true roll (zero skid). AimPoint software was used to quantify exactly how much a range of 0.41 mph might change the outcome of a putt given the same start direction. Figure 1 highlights the results of what percentage of putts would still go in the hole, based on the gradient and angle. The red lines indicate a miss, blue indicate holed and black is the average putt line. When putting using the 3% slope, 60 degree down, there was over a 3ft variation in the finishing distance between the fastest and slowest putt.

The results clearly show that as the slope gets steeper the variance in launch characteristics accentuates the variance in ball speed, causing the ball to slow down at difference rates. The participant tested had world-class speed control with only a 0.24 mph variance across 10 putts, however a greater variance will accentuate this even more. The results also showed that smaller uphill angles are more forgiving of speed variances than cross-hill or downhill angles. From a strategic perspective, it should be obvious where the ideal position to putt from is and from a performance perspective it is important to understand that having consistent launch conditions can have a big effect on distance control. Despite this, some natural variance in speed must be expected (golf is an outdoor sport), and when facing a steep fast downhill putt, it is dramatically harder to make than the equivalent uphill putt (Wesson, 2008 & Holmes, 1991). This brings implications to players of all abilities and probes the question should golfers be more concerned with finishing a certain distance past the hole or optimising the effective size of the hole to give them the best chance of putting.

Putting is a game of percentages – be sure you know where the odds lay in your favour. Given that the golf ball can lose up to 30% of its initial speed before it gets to true roll, identifying this point is clearly important for a player to be consistent on the putting green. From a coaching perspective, a player needs to be able to consistently control ball speed, along with launch, spin and roll values in order to achieve a consistent end distance. A consistent strike point is also required for this to occur. The authors would also stress, that the golfer in question is inside the top 60 in the world ranking (September 2015) and in their experience don’t believe a human can be much more consistent with ball speed immediately after impact.

“Most three putts aren’t caused by bad green reading, but by bad judgement of speed”
Ben D. Crenshaw

References

Pelz, D. (2000). Dave Pelz’s Putting Bible: The Complete Guide to Mastering the Green. New York: Doubleday.

Karlsen, J., Smith, G, Nilsson, J (2008). The stroke has only a minor influence on direction consistency in golf putting among elite players. Journal of Sports Science, February 1^st 2008; 26(3): 243-250

Holmes, B. W. (1991). Putting: How a golf ball and hole interact. American Journal of Physics, 59, 129-136.

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