Dear Neville,
I teach the fundamental of achieving squareness at the bottom of the stroke before impact. In my opinion, a putter design and setup that promotes neutrality in the stroke is best.
By that, I mean the design and setup have the stroke's bottom right in the middle of the stance, dividing the body symmetrically left and right. That gives me a design without offset, a comfortable and natural stance, a neutral "no-hands" grip form with palms opposed and neither hand offset lower than the other in a pronounced way, level shoulders, and a putter-face at address that naturally bottoms out exactly in the middle of my stance beneath my nose.
This allows me to start the stroke straight back with a lead shoulder drop moving the whole triangle intact and move the putter-head to a top-of-backstroke position that then fits the biomechanics of my shoulder-frame orientation so that the free-falling of the putter-head in the downstroke happens by gravity right on line. The putter-head will reach the bottom of its stroke exactly in the middle of my stance, exactly beneath my system's pivot in the clavicle area, so long as I do not interfere with the falling by handsiness or guiding the stroke. The symmetrical location of the bottom of the stroke is pretty easy for the body-in-action to register, both as a goal and as an achievement, because it is "the" natural posture of shoulder-frame relating to torso and lower body with body facing forward.
I am aware that certain putter designs, as well as setups and grip styles, promote uneven shoulders and give dominance to one or the other hand and arm. For example, the left-hand-low grip has the lead shoulder lower than the rear shoulder, and tends to place full emphasis on the left hand and arm with the bottom of the stroke being closer forward in the stance in the direction of the lead shoulder socket. Conversely, a putter like the new Nike Blue Chip Oz has a hosel design that forces the lead shoulder high, and this also moves the hands closer to the front of the stance, off the symmetric bottom. The former shifts the hands forward a bit from gravity, and the latter shifts the hands forward a bit from biomechanics, but the result in both cases is moving the bottom of the stroke ahead an inch or two off center from the body's midline.
Also, there are putting techniques that encourage a "dynamic" movement of the hands ahead of the putter through the impact area. Harold Swash teaches that a "tangential blow" of putter-face against ball above the ball's equator while the putter-head is moving up from the bottom of the stroke is best, as he says it best promotes true roll (online with minimum energy wastage). Others teach "holding" a bowing of the left wrist targetward during the through-stroke, which effectively delofts the putter and gets the hands slightly ahead of the putter-head.
I personally do not like these combinations. To me, the fundamental is achieving squareness at the bottom of the stroke before impact, so that the putter-face is square and moving square through the ball on a slightly upward trajectory. This keeps my hands utterly out of the stroke and keeps the stroke VERY neutral and natural. I also prefer it in the belief that achieving the truly "natural" orientation of level shoulders and torso and lower body facing forward when the putter divides the body exactly in the middle is preferable to achieving any other "bottom" positioning of the body in the stroke, given the symmetry and mammoth familiarity one has with the "natural" posture of neutrality. The oddity of posturing involved with hands-ahead setup or dynamic movement seems to me to be a source of weakness in the stroke's stability and repeatability.
In the short run, one has to "get used to" where the bottom is and strive to recreate that pattern in the setup, grip, and movement. In contrast, everyone already knows where the middle of their body is and setting the putter there just happens "naturally" so long as you don't get gimmicky. And letting the putter return to this bottom during the stroke is also natural and will occur without any conscious involvement other than making sure you DON'T do something special with your hands.
In the long run, too, there is nothing in the physics of impact about hands-ahead that really recommends it, or that cannot be accomplished without hands ahead, at least nothing that I am yet convinced matters enough to warrant the trouble and risk of changing from a neutral stroke pattern. The "good" physics of impact comes from a square face with the center of gravity of the face moving on a slightly vertically arcing trajectory through the center of gravity of the ball in a vertical plane aligned at the target with appropriate putter-head speed at impact, with the trajectory through the ball at impact being either level to the ground or at least not substantially directed into the ground or into the air. Ideally, the loft of the putter as presented dynamically to the ball at impact will feature the face being flush or perpendicular to a radial from the center of the ball to the point of impact on the surface of the ball, rather than some sort of oblique blow. Since the dog ought to wag the tail, the problem is usually that the putter design is "forcing" the golfer into odd patterns to try to make this "good" physics happen. If you start from the golfer and the desired pattern of stroke and impact physics, then this is what determines the putter design in terms of hosel and loft and lie.
Hands-ahead is most often recommended as a technique that prevents or minimizes left-wrist breakdown and occasionally as a technique that keeps the putter-head low and headed down the line. For me, with a true pendulum stroke with "dead hands," left-wrist breakdown is a non-issue and I ignore the whole subject. Only handsy golfers have this issue. As far as keeping the putter-head low, I believe that just not using your hands and letting them hang naturally and stay hanged during and throughout the stroke is all that is required for keeping the putter-head low. I don't think it is a good idea to get involved in managing the hands in any artificial way to keep the putter-head lower than it would naturally go in its arcing past impact. As far as whether something artificial in the hands action is required to keep the face moving on line through impact, I just don't believe this, and instead believe that the biomechanics of an "in-plane" shoulder stroke (whether vertical or tilted) keeps the putter-face square to the plane of the stroke, and if the setup alignment is good, this plane matches the putt line so the face stays square to the putt line on both sides of the ball, naturally, and without the need for any hand action.
The one issue is whether hands-ahead are really needed for generating "true roll" -- that is, an impact pattern that gets the ball rolling as soon as possible for the green surface, without unnecessary skidding, hopping, or bounding, with waste of energy and deterioration of line and the resulting inconsistency from day to day. I understand from the work of Dr Norman Lindsay that backspin is minimized and early forward spin promoted at impact by a low center of gravity in the putter-head and impact slightly above the middle of the face, so that the "gear effect" works best to get the ball rolling or spinning forward as it will once any skidding is completed. [See Dr Lindsay's technical discussion on his website:
http://www.lindsayputters.com.] Back spin is the enemy here, as this loses energy and is also associated with launching the ball into the air a little. The more dramatically the ball is launched, the greater the risk the ball will bound off line, and the harder it is to get the ball-surface friction going to make the ball spin and roll instead of slide. The hitting of the ball with the higher part of the putter-face is contrary to the general pattern identified by Werner and Grieg, How Golf Clubs Really Work and How to Optimize Their Design (2000), where they observe that current pros typically impact the ball slightly below the midline on the face, while amateurs hit the ball "too high" on the face slightly above the midline. The idea is that pros control their stroke pattern much better so the sole bottoms out consistently at the same point in the stance and then rises slightly into the back of the ball, while amateur have inconsistent stroke control and mismanage the face past the midpoint in the stroke into impact and often stub the putter sole by going lower than the bottom of the stroke established at setup. Reconciling Lindsay's physics, one would assume that for the putter-face to impact the ball with the higher portion of the face while also keeping the face flush to the surface of the ball at impact, without sending the putter sole lower than the bottom, would require either (a) negative loft in the design, (b) a hands-ahead technique that dynamically delofts the putter at impact so the top half of the face can get to the ball, or perhaps (c) a setup that keeps the sole of the putter a certain height above the ground in establishing the bottom of the stroke so there is just the right room to impact the ball past the bottom while the putter-face is still going lower than the bottom, or even perhaps (d) moving the ball back behind the bottom so that the putter is still descending in its arc when impact occurs.
All of this seems very tricky to me, and so I have to be convinced that the trade-off in increased trickiness is really worth the loss in naturalness. So far, after trying this stuff for years, I don't really see that great a difference in line or distance control form going for so-called "true roll," but I'm still working at it. The recent work of Dr Lindsay, in particular, has rejuvenated my interest in this problem.
So, no, I don't like hands-ahead, so far at least, although I'm still open on the subject and willing to learn more.
--
Cheers!
Geoff Mangum
Putting Theorist and Instructor
The PuttingZone.com
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