I have been away for a while and researching new leads on putter balancing along with my technical team. We are pleased to announce that we have found a way to explain the correct balance of putters and the effects of back weighting combined with head weight and length. This may help some of you to adapt your putter for better performance.
We are also looking into the face/toe balance of putters combined with offset in relation to the arc of the stroke and appropriate rotation of the putter face. This may be opening up a can of worms but I make no claim to be the oracle on these matters. I welcome any input that you all may have and I am looking for scientific evidence either confirming or disproving the theory.
First of all lets get down to the dynamic balance of a putter
Over the last few years we have seen 3 major developments in putter weighting. Firstly, the standard head weight has increased from an average of 330 grams to 355 grams. Secondly we have seen the rise in the use of backweighting. Thirdly, the development of thicker grips (particularly on the lower portion of the grip) which makes the putter feel lighter.
Increased head weight helps to promote a smoother, slower tempo and if a putter is cut down in length then it will feel lighter, thus a heavier head will be of some use in this case. The question is how you want to swing the putter, from the head or from the hands. By pushing the balance further towards the head you create a heavy dynamic balance and by adding it on the butt end you lighten the dynamic balance. Too heavy can be a problem for golfers who are trying to reduce the amount of influence from the hands (Phil Mickelson) and too light can be a problem for golfers who like to feel the head swinging and releasing (Tiger).
Extra head weight is fine if you have a shorter putter or want to encourage a slower tempo but the more you add the more you have to think about balancing it out with extra weight at the butt end. Furthermore, a lighter head with back weighting and a thicker grip will produce a staccato, pop stroke (Jason Dufner) which may suffer under pressure. Bubba has a putter head weight of 400grams with a 100gram backweight. This offers a stable stroke and although the putter is heavy he can still maintain a quicker than average tempo.
The placement of backweighting is important. The back weighting systems freely available on the market are all inside the shaft and at the tip of the butt. In some putters the weight inside the shaft can affect the resonance or feel of the putt, especially on longer putts. Research has already proven that benefit of back weighting increases depending on how low it is in relation to the grip. Under the lower section of the grip provides the best result. We have developed our own back weighting system which is a 50gram lead tube curled around the shaft under the lower part of the grip and over the shaft. This makes it very difficult to get the grip on and it does thicken up the grip circumference by 3mm.
Summary (all based on standard tempo, 72-80BPM)
Long putter (+35â€) -> Lighter head weight (330g or less) -> Back weighting not necessary
Mid length (33.5â€ - 35â€) -> standard head weight (330g - 355g) -> 50g back weight under the lower portion of the grip advised
Short length putter (33.5â€ or less) -> heavy head weight (355g - 430g) -> 50g-100g backweight, combined with a thicker grip necessary.
Face/toe balance discoveries
The common and accepted theory regarding toe balance and its relation to the swing arc has never been disputed. Where is it proven that a more pronounced arc requires more toe balance? I understand the fuzzy logic which supports this theory but I am not satisfied with it. This is why I decided to look into it further with a more scientific approach.
Problem: the issue I have with this theory is that the rotational axis of the putter is the shaft. If you hold a face balanced putter horizontally and twist the butt end of the grip, you will notice that the equal balance of weight on either side of the rotational axis means that it becomes less stable. This lack of stability can be improved by moving the centre of gravity further away from the axis and/or by moving more weight to the extremities (higher MOI). The fact remains though that with equal weight on either side of the axis will encourage easier rotation around the axis.
If we take a blade putter with maximum toe hang and hold it in the horizontal position so that the toe hangs down. Now hold the butt end and rotate the club so that the face is now in a horizontal position (just like the face balanced putter naturally hangs) and try to rotate the club in the same way. You will notice that this becomes more difficult and one sided. I like to compare this to the idea of a helicopter which has two opposing rotors which are equally balanced and no matter how heavy they are at each end, they rotate with ease around the rotational axis. If however you only have one heavy rotor on one side, it becomes more difficult to rotate and unstable.
This means that regardless of whether you intend to rotate or not, a face balanced putter will provide the best rotational stability and remain true to the swing path on a well struck putt. On a poorly struck putt, there will be less resistance to twisting around the rotational axis of the putter. On a toe balanced putter during acceleration, the bias of weight on the one side will provide more resistance to twisting on one side of the rotational axis. This will in fact lead to a â€˜holding off' of face rotation. When the putter decelerates, the face will rotate more around the rotational axis.
To cite examples of this I would like to draw your attention to Luke Donald and Phil Mickelson. Luke changed his putter from an anser style Bettinardi to a centre shafted Odyssey. His swingpath has a pronounced arc and the putter remains square to the path, thus rotating. Phil on the other hand has a toe balanced putter, accelerates through the impact zone and holds the face off. This works contrary to the accepted rule that a face balanced putter is â€˜straight back, straight through' and that a toe balanced putter is for 'rotation, release'. A 30Â° toe hang will be neutral and provide a compromise and there are more players using a large mallet head with a 30Â° toe hang (Jason Day). I assume this is to provide a holding off of face rotation during impact and stop it closing down too quickly.