Rolling Brief

“Quantifying the relative and conflicting effects of putter path and face angle on the direction and motion of the golf ball” – that was our goal in producing a research document based on our own extensive testing By Dr Paul Hurrion & Jim MacKay

The putter: the most used club in the bag but the most overlooked part of the average golfer’s practice. Golfers around the world are using the technology available in today’s market to help analyse and improve their golf swing. Technology is transforming teaching and club-fitting, offering golfers three-dimensional, frame-by-frame swing analysis, high-speed video and precise spin rates and launch angles that apply to the golf ball after impact. However, when it comes to putting, rather than analysing what our putting stroke and the ball are doing in detail, we simply opt to buy another putter with little more than hope that it will truly improve our putting performance.

 

DR PAUL HURRION

Factors such as alignment of the putter face, path of the putter, launch angle, speed, impact location, grip pressure, forward or backwards rotation, hook or cut spin, grain, spike marks, slope and even wind can play a significant part in the outcome of a putt.

 

We explain which is the more influential and by how much? Interestingly, our study proved that Face Angle at impact accounted for as much as 92-95% of the starting direction of putts (centre strike with a two degree dynamic loft at impact). The question, then, is how does this translate into making or missing putts? Our data below shows the angular margin for error within which a putt will still succeed.

Distance Angle of Ball Putter Face Angle (92%) from target line

3 feet 2.80° 2.60° 

4 feet 2.20° 2.02° 

5 feet 1.90° 1.75° 

6 feet 1.60° 1.47° 

7 feet 1.40° 1.29° 

8 feet 1.20° 1.10° 

9 feet 1.00° 0.92° 

10 feet 0.90° 0.83° 

12 feet 0.75° 0.69° 

15 feet 0.60° 0.55°

Note: Data produced by The Quintic Ball Roll System (as explained later)

 

During the PGA Tour 2011 season, five players made 100% (minimum 400 attempts) of putts inside three feet where the putter face angle can be up to 2.60 degrees open or closed relative to the target line and the putt still drops (Target line = 0 degrees). But note from more than 8 feet that only a single degree closed or open will cause the ball to miss – it is very difficult with the naked eye to see the difference between a putter that is square as opposed to one degree open or closed. No wonder the percentage of putts made on the PGA Tour drops off so quickly after 8 feet as can be seen from the following official table.

PGA Tour Stats 2011 Season

 

Distance	1st	75th	150th
Inside 3 feet	100%	99.40%	98.88%
3-5	94.29%	87.57%	83.57%
4-8	77.58%	68.80%	64.25%
5-10	65.81%	56.80%	52.80%
10-15	39.18%	30.81%	26.59%
15-20	29.09%	19.84%	16.55%
20-25	27.20%	12.86%	9.40%
>25 feet	10.55%	5.75%	4.33%

Find a straight putt on the practice green. Take six balls and put them in a straight line starting at two feet and every two feet to 12 feet. Start with the ball that is at two feet and work your way back to the ball that is at 12 feet. If you miss a putt you have to start over again at the first ball at two feet.

 

You need to make all six balls in a row to finish the drill. Once you can complete all six balls on a straight putt, try it with a uphill, downhill or even a small breaking putt. Remember, from two feet your putter face can be up to 3+ degrees open or closed to the target and you can still hole the putt! But once you get to 12 feet, it can be no more than 0.69 degrees open or closed – a small margin indeed!

And here is another – the 2-tee drill.

 

How we did the testing?
 

 

Utilizing a fixed Putting Robot with varied optional settings, Quintic Biomechanics Analysis Software, and The Quintic Ball Roll System, our study was conducted to determine and hopefully answer the question: “The Face or The Path - which is more influential in determining the horizontal launch angle (direction) of the golf ball after impact with the putter face?”

 

A: “Straight Club Path – no face rotation” (number of putts = 360)

For the second part of the study, the putter path was randomised by varying degrees, for example, ‘in to square to in’, ‘out to in’, ‘out to square to out’. Fifty-four different face angles were used for the study (random positions), and the Putting Robot enabled ten identical putts at each specific face angle. The average of each set of ten is displayed as a single point in the following graph. Otherwise the methodology was identical to part one of the study.

 

B: “Variable Club Path – face square to path” (number of putts = 540) Specifics of the Equipment

The Quintic Putting Robot is a fixed metal frame which clamps the putter firmly and allows variable and lockable angles to simulate shoulders, neck, arms, and hands angles. It swings freely on an 800 pound industrial bearing.

 

 

Quintic Biomechanics is well known and proven video analysis software, one function of which automatically or manually calculates angles from video footage.

 

 

C: “Variable Club Path and face angle” (number of putts = 1000)

This scientific testing using a fixed robot and a high-speed camera (1000fps) has shown that up to 10 rpm of hook or cut spin imparted to the ball is acceptable as having negligible effect (Stimp rating 15). As soon as ‘hook’ or ‘cut’ spin increase above 20 rpm, it causes the ball to spin, bounce and /or stray from the intended line.

 

Here are common causes of too much hook spin:

• inside to outside putting stroke
• putter face closed at impact
• striking the putt out of the ‘toe’
• putter with lie angle too high (toe high)

...and common causes of too much cut spin:

• an outside to inside putting stroke
• an open putter face at impact
• striking the putt out of the ‘heel’
• putter with lie angle too low (heel high)