Dear Sammy,
The putter face needs to be square both AT impact and also DURING impact. This is, frankly, more important than making "sweetspot" impact at least for the vast majority of makeable putts, as slight off-center impact left-right of center (but nonetheless while the putter face is "square" to the intended line of the putt) will not usually lose enough energy to stop short of the hole, nor will off-center impact cause all that great a problem with line as a result of face twist from the off-centered impact (at least with today's high MOI weighting schemes and a modest grip pressure).
The "procedure" that I recommend for making square impact at and through the ball is not to "make" the impact square but to "let" the putter head swing where it wants to swing, managed by the top of the body's "swingset" in the throat with shoulders aligned parallel to the target line. By this I mean that if the golfer steadies the line of his throat during the stroke like the top bar of a swingset, this creates the following fortuitous situation at the top of the backstroke:
So long as the backstroke forces are mild and result in the path of the backstroke back and up being a) not across the line away from the feet, and b) either straight back or slightly inside and back and up, then simply "letting" the downstroke proceed by its own trajectory in gravity beneath the top bar of the neck will result in the arms and putter swinging down and under back to square and then up and down the line straight and square through impact for a resonable distance past the impact zone. Combined with an appropriate backstroke length, this procedure also sends the ball off rolling with the appropriate touch or pace for the length of the putt.
At address, the line of the throat is positioned to match (vertically above or parallel to) the leading edge of the putter face, depending on the relationship of the bottom of the stroke at the putter face to the midline of the body. With the neck perpendicular out of the shoulder frame, this setting the throat also "squares" the shoulder alignment parallel to the aim of the putter face and hence to the intennded line of the putt.
At the beginning of the backstroke, attention is paid to not allowing the forces of the movement to shift the throat line out of square. This is mostly accomplished by a combined and coordinated tension in the slightly bent knees and the muscles of the top of the back and the neck, with a tone ever so slightly greater than the tone in the relaxed gut / abdominal muscles, where the stroke action occurs. (The throat-setting muscles sort of "sandwich" the gut muscles with stability.) With this setting and steadying of the throat line, the lead shoulder can then shove the "stick" of the arms and hands and putter down, back, and under the throat to the top of the backstroke with a gentle action that does not overly challenge the top of the body and the throat line. (The backstroke action itself is something of a toss-back as in a tennis serve, with instincts from green speed and targeting of distance handling the "size" of the toss and the length of the backstroke to which the tossed-back putter coasts to and comes to a conclusion under the gentle retarding forces of gravity.) The throat line is then still square to the line of the putt, aligned as was the putter face at address. This is true even if the alignment of the shoulders beneath this "top of swingset" is a little out of square, twisted slightly rear shoulder back off line a bit.
When the putter and arms and hands reach this top-of-backstroke position, the throat is still square to the line like the top bar of a swingset. "Letting" gravity take the whole assemblage of arms, hands and putter wherever gravity wants to take them, with the golfer simply "riding" the stroke or keeping up with the swing with his shoulder frame benath the steady throat line, as opposed to the golfer "bringing" the putter down with voluntary, deliberate moving or putting of the putter down and thru with his muscles, the swinging down and under the throat will do two things very nicely -- resquare the shoulders and the putter face at the middle / bottom of the stroke arc beneath the throat (or slightly to the front side of the stroke past the throat line) and then the throat's steadiness combined with the shoulder alignment and the forward swinging momentum of the swinging arms, hands and putter will direct the putter head square thru the impact area and down the line on a slight rising.
The key to this "letting" the stroke assemblage freely swing down and thru and up is keeping the line of the throat steadily positioned as it was at address withOUT using the muscles to bring the stroke down and thru. In particular, there is one muscles to watch out for especially, the
brachioradialis in the forearm on the outside of the elbow. (If you rub / slide the fingers and palm of the right hand up the left forearm on the top side of the forearm to the elbow, the brachioradialis is the puffy-shaped muscles that ends up beneath your right hand where the fingers wrap.) If this muscle (usually on the lead side of the stroke) activates during the downstroke, the golfer is "bringing" the putter down instead of "letting" the stroke swing on its own steam and on its own trajectory as constrained by the throat and shoulder alignment. This is why top golfers with the flatstick end up liking "soft" arms and a light, inactive grip pressure in the hands. It has nothing really to do with "sensitive" feel or control in the hands, and instead has to do with leaving the putter alone as it swings down and thru. This is a dead-hands stroke, as well as a dead-arms stroke, and all the shoulder frame is doing is trying not to stifle or corrupt the natural swinging of the stroke beneath the pivot by keeping up with the timing of the swing. The lead shoulder and the putter head end up staying coordinated during the stroke, the lead shoulder not getting ahead or behind the swinging of the putter head, and hence there is no "lag" feel of the putter to desire or manufacture. The "sign" in the feel of the hands of a coordinated downstroke like I am describing is "nothing changing", especially under the tips of the thumbs where an oval patch of skin meets the material of the flat handle. So long as there is no sense in these two patches beneath the thumb tips of stress, strain or shear forces of the skin, the stroke is well-timed and coordinated and "let" alone in gravity.
How does the putter face resquare at the bottom of the stroke? In the making of the backstroke with the lead shoulder "rocking" with a gentle toss back down and back and under the fixed throat line, the inner oblique muscle that stretches in a sheet from the rib cage on the lead side onto the lower skeletal structure at the pelvis has an elastic memory. The fact that the hips and pelvis remained stationary as did the throat line in the backstroke anchors the inner oblique and the stretching elastic properties of the inner oblique sheet of muscle will naturally return the upper torso and shoulder alignment to square upon relaxation. The inner abdominal oblique muscles work like this:
"The internal oblique performs two major functions. First, it acts as an antagonist (opponent) to the diaphragm, helping to reduce the volume of the thoracic (chest) cavity during exhalation. When the diaphragm contracts, it pulls the lower wall of the chest cavity down, increasing the volume of the lungs which then fill with air. Conversely, when the internal obliques contract they compress the organs of the abdomen, pushing them up into the diaphragm which intrudes back into the chest cavity reducing the volume of the air filled lungs, producing an exhalation.
Secondly, its contraction rotates and side-bends the trunk by pulling the rib cage and midline towards the hip and lower back, of the same side. It acts with the external oblique muscle of the opposite side to achieve this torsional movement of the trunk. For example, the right internal oblique and the left external oblique contract as the torso flexes and rotates to bring the left shoulder towards the right hip. For this reason, the internal obliques are referred to as "same side rotators.""
(
Wikipedia, Internal Oblique Muscles.)
If there is significant "reaching out" to the putter at address, or if there is a significant inside trajectory of the backstroke combined with a big backstroke, the relaxing and resquaring of the putter face in this fashion may occasionally result in the putter face resquaring fine but repositioning the sweetspot slightly inside the line closer to the feet, causing the impact point on the ball to shift toe-ward on the face. In my experience, this shift may be around an eigth of an inch toe-ward off-center, which does not cause a big problem with the straightness of the roll or the energy of the roll, at least on makeable putts inside about 15 feet or so. Because of this, the golfer does not want to reach out to the putter in adopting his address, but instead bring the naturally hanging arms and hands out on the gantry of the legs to dock with the flatly-soled putter wherever the handle is poised in space waiting for the arrival of the hands. Nor does the golfer want any more than at most a gentle, very modest inside-curving pathway for the backstroke, and hopefully little or no shifting of the shoulder frame out of parallel with the intended line of the putt as established at address. But if in the event the putter head shifts inward a little as it swings forward, the golfer needs to place the highest premium on letting the putter face requare and on letting its momentum-driven trajectory remain unaltered by effotrs to make perfect sweetspot contact, and be content with square but slightly offset impact. The effort to get the sweetspot exactly onto the back of the ball is just not worth the risk of changing the face out of its natural square return.
If you want to experiment with cause and effect when the backstroke is slightly inside and the relaxed downstroke allows an inward drooping of the putter head, just make a few such strokes and watch the impact point carefully. Then START at address by positioning the putter's sweetspot about the same distance out past the exact back of the ball, make the same slightly-inside backstroke with a relaxed downswing, and the putter head will make impact dead on the sweetspot.
Why does the swinging momentum of the putter want to stay square thru and past impact? The abdominal obliques will resquare the shoulder frame (if it got out of square in the backstroke) by the time the stroke reaches its bottom / midpoint. Thereafter, the stability of the hips at this point absorb any tendency of the shoulder frame and torso to continue twisting past square / parallel to the intended line (the right hip in particular stops the twisting once the upper torso resquares). At this point in the stroke, the shoulders are aligned parallel to the putt line and the top of the swingset (the throat line) is stable in space and will resist the tendency of the stroke momentum to force the throat line to swing left (lead-side) of the original orientation at address. So long as the top bar of the swingset remains stable, the "swing seat" of the putter head will rise straight down the line thru impact in accord with the shoulder alignment -- i.e., the putter head will stay square and slightly rising thru and past impact. All by itself.
This is purely a biomechanical arrangement of the human body in space and a management of the forces of the stroke mostly by holding the top of the swingset at the throat steady with minimalist voluntary forces in the backstroke and downstroke.
The momentum of the putter and arms and hands swinging beneath a steady throat will cause the lead shoulder to rise vertically up from the ground in the follow-thru while the impact is ongoing and beyond a little, and anything other than this will spoil the squareness of the stroke. A golfer who likes this sort of bringing the putter down with the lead shoulder moving back thru impact does not really putt where the putter face aims and is subject to streakiness and at best so-so touch.
If the golfer "brings" the putter down and thru impact, a couple of bad effects get introduced that tend to unsquare the putter face. First, the biomechanical properties of the elbows are such that they hinge only one way -- away from the front of the body. If the golfer "uses" his hands and arms to bring the putter down, he is actually moving his forearms and hands with his upper arms and elbows. If he activates the lead-side muscles either side of the elbow (especially the brachioradialis), the stroke path will gain a tendency to run from inside to outisde thru impact due to the flexing of this elbow. If the golfer powers the stroke down with the muscles of the rear-side arm, this will tend to either push the stroke in to out by elbow felxing or pronate the rear forearm to close the putter face on an arcing to the inside thru impact (a pull). This is a non-dead-hands stroke that definitely causes problems. Secondly, by applying muscle action, the golfer speeds up the arms and hands ahead of the lead shoulder, and this takes line control away from the biomechanical setup of the shoulder alignment and tosses the line to the ravenous wolves of the hands and arms while creating a lagging of the putter head behind the hands. The hands and arms outrace gravity whenever the golfer "brings" the putter down and this lagging will most usually cause the toe of the putter to flare open. Contrary to Scotty Cameron's notions of so-called "toe-flow", the lagging of the putter head in a handsy-armsy bringing down of the putter will leave the heavier-weighted toe behind, opening the face. Thirdly, the intentional bringing of the putter assemblage down and thru tends to shove the line of the throat left (lead-side) of its square alignment at address, and this is an "over-the-top" move that results in putting a ball along the ground in a pull.
Now, if the golfer cannot reach this level of relaxed, natural stroke, he needs a Plan B. Plan B is to pre-plan the path of the stroke thru impact visually and kinesthetically before starting the stroke by looking where the putter face aims thru the center of the ball for about 5 inches and imaginging the look and feel of a square stroke thu impact. Then, when making the thru-stroke the Plan is to make sure the putter face rises down this little line segment on a slight rise thru the back of the ball so that the sweetspot remains directly above this line segment, so that the face stays square until the end of the line segment, and so that the ball actually starts off exiting the setup straight down this "stem" of the T established at address by the opposite / mirror T of the putter head behind the ball. This action is most easily performed by holding the throat line steady into the bottoming of the stroke and then "moving" the putter head slightly up and down the line with the lead shoulder rising straight up away from the balls of the lead foot (or whatever point on the ground that is directly below the lead shoulder at address).
Setting up like Jack Nicklaus with the right palm and right forearm pistoning out away from the body straight down the line at the target is one way to get this done fairly effectively. Annika Sorenstam thinks about moving her hands and elbows along a straight path maintaining the same relative distance of elbows and hands out from the frontal plane of the body. So there are various "intentional movement" strategies to perform this "good physics" impact. The "pop-up" gate used by Don Pooley is another way: practice with the back of the ball sticking back behind two tee pegs positioned so the line from peg to peg "aims" square at the target (e.g., a 4-foot straight putt aimed at the center of the cup) and then deliver the putter face square and slightly rising into both tee pegs simultaneously, with no difference in when the toe-side of the putter face hits its peg from the time the heel-side hits its peg. then remove the tee pegs and repeat the body action that gets this done.
As Paul Runyan has said, "Putting is primarily developing a deep knowledge of how to hit the ball squarely" (or words of that tenor). Its mostly setup and putting by managing the top with minimalist effort in the backstroke and letting the downstroke take care of itself with the proper biomechanics, combined with the physics realization that the putter head needs to start impact square and persist square while the putter and ball remain in contact. Letting the swinging putter define its own trajectory beneath a steady throat line and with shoulder alingment parallel to the intended line, given the elastic and inertial properties of the body structure, naturally and effortlessly causes the putter head to rise on a slight arc square thru the ball and down the line. Another aspect to gravity timing is that the exact bottoming out of the stroke always occurs at the same location in both time and space, whereas in a bringing down of the putter there is a tendency to miss the time and to broaden or slop over the exact bottom of the stroke. In a square, straight stroke, the sole of the putter flattens in the same position it had at address at its lowest point in the stroke arc right before the sole "takes off" evenly and level from the surface on a slight rise square into the back of the ball and thru impact down the line a bit. This action keeps any loft directing the ball only vertically above the intended line on the ground, whereas an "unlevel" takeoff from the deck of the green (toe up or heel up, not both "wheels" of the plane under the sole coming off the ground at the same moment as in level takeoff from the deck) will mis-direct the ball slightly off line. In addition, in the case of a tilted-plane or gating stroke, the trajectory of the putter head thru the ball during contact is rising on a somewhat diagonal path from far to near and from low to high thru the ball, which is a glancing blow with a high potential for mis-directing the ball off-line. An even takeoff rising straight down the line avoids all this, and that is where the putter head is TRYING to go by its own momentum and where it will go so long as the golfer doesn't mess it up but instead allows or lets it happen.
There is a neurological angle to all this as well. First, the voluntary moving of the putter, arms and hands down and thru impact is conditioned in the brain by "population vector coding" by which the accuracy and potency of the perceptual processes for appreciating the spatial relations between the putter-as-tool and the body and the target and the target line vest the movement processes of the brain with preferential tendencies to move the relevant body parts where intended. (There is no clear break between perception and movement, and the processes are integrated into a unified action by this interrelationship of "population vector coding" that uses perception to generate the stroke plan and movement like a battle map.) Whether the golfer actually makes the stroke along the intended line, then, is subject to some variables in the perceptual process that matter every single stroke. Contrary to the outdated notions of sports scientists in the 1970s that feedback will "groove" or "automate" the stroke movement, what is a more accurate statement of the situation is that rote repetition will groove a "more-or-less accurate" stroke action in about the same way riding a bicycle will grove the balance and peddling action -- that is, movements not especially suited for ballet or surgery but simply gross movements that more or less get the job done. This is never good enough for putting. I do not believe there is such a thing as a grooved intentional stroke movement apart from the accuracy of the perceptions of space and the careful planning of the motion in light of knowledge of what works and why and therefore what to move how and where and why. This sort of accuracy of perceptions and knowledge of what works is implicit in excellent performance of elite golfers, and it really needs to be explicit or these golfers are subject to streakiness over time. In general, most golfers in fact have a mismatch between the reality of where the stroke should go in space, the perceptions of where the stroke should go, the motor plan for where the stroke should go, and the actual direction that intentional activation of the muscles sends the stroke in space. This mis-match from reality to where the stroke actually goes is on the order of a "cone of error" of about eight degrees. This means that if you located the apex of a cone at the lead shoulder and aimed a line from apex straight out the middle of the base of this cone directly at a target, the perceptions generated by most golfers is off this directional line by a few degrees, and so is the motor plan in the brain, and so is the actual movement direction in relation to the real aim direction, and this "cone of error" has a spread of about eight degrees for 90% of the strokes.
Population vectors, after
Apostolos Georgopoulos (University of Minnesota Neuroscience):
See also
Alex Pouget, University of Rochester Neurosscience.
The whole intendment of instruction is to render the golfer mindfully capable of minimizing the spread of this "cone of error" on a consistent basis, partly by perceptual sharpening and making sure perceptions are accurately generated, and partly by understanding and coping with the biomechanical and anatomical influences that promote error. In my experience, this "cone of error" for 90% of the strokes can be reduced to about 1 degree after extensive practice and learning over several years, which is pretty good. However, also in my experience, the utterly reliable physics of gravity withOUT intentional muscle activation in the arms and hands to bring the stroke down is superior in reducing this "cone of error" and converts an intentional movement problem largely into a setup problem of biomechanics and balance stability at the top of the stroke with an effortless, repeating stroke. But of course not everyone can perform this sort of stroke, as the vast majority of golfers are dead set emotionally and intellectually from learning and trusting it. That's why the vast majority of golfers are not so hot at putting and only a rare few individuals ever advance to this level.
For example, Loren Roberts has been measured to have a tempo from start to top of backstroke of 950 milleseconds (ms), whereas a gravity-sponsored backstroke is closer to 1,000 ms. So he is a mere 5% off, adding only 50 ms worth of intentional muscle action to his backstroke. he has also been measured to have a downstroke from top of backstroke to top of thrustroke of 63 beats per minute, compared to a gravity-sponsored stroke of about 60 beats per minute. So again, Loren is only adding at most 5% to the natural gravity acceleration and timing of the stroke. Ben Crenshaw is about the same ("Once I start the putter back, it seems as if the stroke completes itself.") Almost all lesser golfers have a backstroke timing closer to 750 ms -- they "put" the putter back and then "put" the putter down and thru with voluntary mucle action. The normal pattern of backstroke timing to downstroke-to-impact timing is a 2-to-1 ratio, so that a 750 ms backstroke corresponds to a 375 ms downstroke-to-impact. (A more gentle gravity-sponsored backstroke is nearer 1,000 ms and the downstroke-to-impact timing is closer to 500 ms, one-half, and this is the WELL-LEARN and UNIVERSALLY GROOVED timing of the adult arms swinging relaxedly back to the sides. This quicker velocity of the stroke and its concommitant forces employed by so-so golfers does damage to balance and accuracy of the stroke, and leaves these golfer forever contending with the "cone of error" whose spread is widened by poor aiming / spatial perceptions and the violence of the stroke action. Rote "grooving" of a stroke motion won't save these golfers from this error as is so often stated by teachers who don't know what to teach a golfer other than to tell them to practice a certain movement over and over until it is "grooved." (Teachers who still rely exclusively upon rote repetition of movements with training aids are basically stuck in an outdated approach to learning precise and consistent motor skills.) That really doesn't work as supposed and in any event leaves the golfer dependent on the training aid and on streakiness without the ability to self-coach with a knowledge of cause and effect.
Second, the visual system neurologically has a speed limit of about 0.20 seconds (200 ms), and watching movements faster than this essentially deprives the golfer of hand-eye coordination. The signal processing of light from images of objects in the world, especially moving objects like putter heads coming into the back of a ball, takes a little time to be integrated and used for hand-eye coordination, something on the order of two-tenth of a second (200 ms). When the golfer uses the kindness of gravity to accelerate the stroke into impact, the vast majority of strokes stay within this speed limit for an appreciable segment of the stroke. In comparison, the 375 ms downstroke are shorter and quicker by 30% than the 500 ms downstrokes and present much less opportunity for effective hand-eye coordination form the same impact velocities of the gravity-sponsored stroke. Hand-eye coordination is a feedback-based corrective process that takes the visual feedback of error and plans a corrective action. These faster strokes basically leave the golfer at the mercy of feedFORWARD corrective processes, whose accuracy depends upon perceptions of error from proprioception plus well-trained memory for where the putter needs to move thru impact to an end position with its look and feel and ideally also with knowledge of cause and effect for how and why to get to that position. Slower strokes have a much greater role for BOTH feedback-based hand-eye coordination AND feedforward corrective action if needed to overcome error.
Third, there is a BIG difference in movement processes between activation of muscles and inhibition of mucle activation. But there is NOTHING for the golfer to do with relaxation of muscles in gravity except inhibit the use of them. The quick and dirty downstroke is an intentional activation of muscles, but the kinder, gentler gravity downstroke is really an inhibition of muscle activation that allows a free-flowing relaxation in the downswing. (At the top of the backstroke I sometimes think: "Don't use the forearm muscle on the left to bring the stroke down; just let it flow down with the thumb tips feeling nothing changing.") The physiology of exhaling is really a relaxation of the diaphragm muscle that pulled the ribcage open to suck in air, combined sometimes with a contraction of the inner abdominal obliques to squeeze air back out of the lungs. So a relaxed downstroke is naturally coordinated in timing and feel with a relaxed breathing out. And the brain is MOSTLY inhibition of signalling, by which only the relevant processes for various actions get engaged without confusing signals from non-relevant brain processes. So NOT making the downstroke is actually quite a bit more natural and instinctive than making the downstroke, similar to relaxed exhaling, contrary to popular opinion otherwise.
This is why the really excellent golfers eventually evolve to a slow stroke with a premium on relaxed, instinctive backstrokes, and minimalist use of muscles to "make" the downstroke. The result is a higher percentage of square and solid impacts with superb touch on a consistent basis. Add to that cause and effect knowledge, and you're in business!
Cheers!
Geoff Mangum
Putting Coach and Theorist
PuttingZone.com
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