First, "feedback" according to motor sports science is not understood by golfers or golf teachers, so far as I can find out by diligent search over twenty years. Nada, buttkiss. And that's pretty bad for people who keep bleating on about "feedback" in golf and golf instruction / learning, as in Dave Pelz repeating ad nauseum that "perfect practice makes perfect performance" with his supposedly "perfect feedback" training aids, and utter nonsense like that.
NOW HEAR THIS well-meaning folks teaching golf: if you ever read motor sport experts on the definition of "feedback" (which is not too likely, since you probably haven't read much or any so far), instead of merely hoping the public believes you know what you're talking about, you will discover for the first time that "feedback" is defined thusly:
First, there is "Knowledge of Results" (KR), or what happened in relation to what was intended to happen.
Second, there is "Knowledge of Performance" (KP), or awareness of what body action caused the error in what happened.
"Learning or skill development" consists of changing the faulty KP to eliminate or reduce the error, understanding the body action in terms of cause and effect, vesting in this as "sound", and then practicing this deliberately to make the movement pattern's "habit" hew as close as possible to the well-comprehended ideal pattern. For purposes of a putting stroke, the skill is considered "closed" in the sense that the stroke is always the same setup and posture and movement pattern, except that some strokes are larger than others. That's a good thing that golfers don't quite "get", because to bad golfers the sort of stroke to make is always dependent upon the circumstances of the putt for read and aim and pace, but it should NOT be, and that is why almost all golfers are bad at stroke. Once aimed in the read and with a sense of touch for the read, the stroke is NOT NEGOTIABLE! It's always exactly the same movement pattern. So learning a "sound" stroke OUGHT to be easy if any golf instructors knew anything about teaching one.
So, a "technology" that purports to provide "feedback" to golfers about putting designed by people who are not putting instructors knowledgable about "feedback" and "sound" stroke patterns and how the stroke integrates with reading, aiming, and touch or pace / distance control are HIGHLY UNLIKELY TO GET THE PARAMETERS TO MEASURE EVEN CLOSE TO HELPFUL. And of course they don't. And they don't really care, either, since when this is explained to them that their chosen parameters are all wrong and unhelpful, they AGREE and then say "But we've already made it this way, so we have to sell it." (Christian Marquardt, non-golfing designer of the SAM Putt Lab, said to me in Malmo, Sweden, in 2008). A very similar exchange occurred between me and banker-cum-putting-trainer-designer Richard Jaekel concerning his Zenio device at his Country Club in Frankfurt Germany in 2009. Heaven help us poor golfers and save us from these well-meaning training aid designers, who have no significant knowledge of the skills they purport to be training.
To answer your two-part question, it is really a one-part question based upon the two-part definition of "feedback" and what that has to do with "learning" a skill.
The device OUGHT to measure what results in the putt compared to what was intended AND measure what body action was used to generate the result. The SAM Putt Lab does NOT measure results of what was intended unless you accept the designer's defining the result as "stroke the ball squarely down the line of aim" as adequate. I sure don't. This has nothing to connect the stroke to sinking a putt or even executing a putt according to the read and aim and touch / pace required; moreover this has nothing whatever to do with the BODY postures at setup in the aiming process or the BODY movement pattern in relation to the read and aim and touch / pace. Hoi vey!! And obviously the SAM Putt Lab makes NO effort to measure the body action at all, so the "result" measured by the device is utterly unconnected to skill development. No "KR" and no "KP".
Now really it's worse than I have described. The golfer comes to the SAM Putt Lab NOT sending balls off the same direction the putter face aims at address, a fact that is empirically and demonstrably true in about 90% of all golfers every time they make a stroke or have made a stroke over the past 150 years. But of course a non-golfing "technology" designer of a putting training device intent on cashing in from golfers wouldn't actually know this little inconvenient fact, would he? Since this is the case, the stroke being trained forces the golfer to fit his "square peg" stroke into a perfectly "round hole" pattern. Okay, you say, isn't that a good thing?
No, it's a bad thing. Fist, the golfer is not aware that this is what he is doing, so there is not learning going on -- there is simply idiotic repetition. Skill does not come from repetition, but from understanding sound "know how" and then making that as habitual as possible but also knowing what is supposed to be the ideal sound pattern of body action to cause good results and avoid or minimize errors. If you are one of the millions and millions of uneducated golfers who swear by the mantra "groove the move", then you should ask yourself why pro golfers spend 5 hours every day on the back of the driving range in their fifteenth year as a veteran pro golfer. Obviously, Tiger Woods has grooved and re-grooved his swing several times and still has trouble. In contrast, Jack Nicklaus, the greatest golfer in the history of the game, never spent this sort of idiotic wasted time on the back of a driving range. If he experienced a swing problem in a round that he couldn't fix immediately with self-coaching "know how", he went to the range after the round and hit ONLY as many balls as required to figure out the body action that caused the flaw and the body action that fixed the flaw, and then he went home. He said this was often a matter of about 7 balls. Got that?
Second, the golfer is fitting the "square peg" stroke into the "round peg" stroke assumed to be good by the non-golfing designers from the "square peg" setup postures. This generates oddities in the movement pattern. The end result is unaware setup and unaware movement issues, INSTEAD OF paying attention to the body action and learning the cause-and-effect "know how".
Third, because the stroke repetition is going forward without any reference to distance control or pace, the "good parameters" are "chased" mostly by alterations in the stroke timing pattern. This is an especially stupid way to train in putting, because ALL OF THE TIMING in the motion is completely consumed only by the pace control. It's just physics, folks, and not arguable. The pace and distance comes from the velocity of the putter head mass at impact, with some effects by squareness of face in impact and centering of the putter head mass thru the center of mass of the ball in impact. But these two sub-issues of squareness and centering of the putter face thru impact are generally far subordinated to the pure timing issue, since everyone wants perfectly square and perfectly solid impact. Once the impact is square and solid, the REAL ISSUE is velocity of putter head mass at impact. It's really the ONLY issue unless the golfer is trying to learn how to make a "cut stroke" on purpose or something like that -- which no one does on purpose with the possible exception of that lousy putter named Billy M. the SAM Putt Lab's idiotic focus only on the stroke without touch ends up having the golfer trying to match some weird "acceleration pattern" or some "rotational acceleration pattern" in order to get a "straight" stroke that is a "round peg" stroke anyway. The changing of timing patterns as a way to correct stroke flaws in this square vs. round context is just physics- and reality-stupid and harmful.
Fourth, the device to the brain becomes a "crutch" that trains a "crutch-only" skill. The brain uses the orientation of the nearby SAM Putt Lab receiver stationed across from the ball set with its plane parallel to the aim of the putter in order to guide the stroke thru impact. This physical and visual pollution of the practice environment detracts from the skill itself. Motor learning science is very clear about this "crutch" learning being deceptive and not what the golfer thinks or hopes he is gaining from practice with such distracting "crutch" devices. Almost all golf putting training aids and devices fail this "don't be a crutch" criterion of goodness, as they are almost all controlling and preventing errors, calling attention to themselves as "tricks to work", and detracting the golfer from paying attention to the body action causing good and bad results.
Fifth, the implicit promise of the device is that the golfer needs to wait for the device to display the data measured before he knows what happened and thereafter should review (if he knows to) what caused the error. This inherently PREVENTS or at least GREATLY DISCOURAGES or DISTRACTS the golfer from paying attention to the body action that he used. Waiting until the display (a matter of 5-10 seconds or sometimes minutes) renders the memory trace of the recent movement a thing of the ghostly past that cannot accurately be reconstructed for diagnosis and analysis. That cuts the very heart out of the learning experience, O My Brother Golfers! Almost every putting training device is built on purpose ignorantly to work in this skill-opposing fashion -- just the technology-provided data, please, wait for it ... wait for it ...
There are similar problems, and the same applies to the Zenio.
But to get back to your question, an intelligently designed technology STARTS with the understanding of the skills in putting and then measures real KR and real KP, and also does so at a level of precision suitable for use by real golfers.
So the golfer needs to use touch to read a putt across a real surface and then aim the putter and then set up to the aimed putter before he is ready to have anything measured for the stroke in terms of any REAL intended result. The golfer should aim the putter face and set up BEFORE the device is placed anywhere near the golfer. Instead, the SAM Putt Lab makes the golfer set up according to the device ready and waiting to measure something, and then however the golfer aimed the putter face, and however the golfer set up his body to this aim of the putter face, the SAM then "locks down the aim" and says, "now make a stroke that moves square and straight down this aim line." That's pretty stupid and unhelpful and in fact corrosive of real skill development.
Even IF the golfer does the reading and aiming and set up before the "technology device" is introduced to the situation, the device STILL has to measure results, not just the immediate area of the stroke. The SAM Putt Lab does none of this. The need is to measure the miss at the hole, if the intended result was to make the breaking putt go in the hole and stay there. Was the miss high or low, long or short, and was the break into or away from the golfer, and was the surface contour tracked in any meaningful sense?
And even IF all of the above parameters are tracked at the correct level of precision, that still does not connect the motion pattern used that generated the error to the BODY ACTION that caused it, so the golfer can gain insight more accurately about what exactly he is doing with his body. If you think "feel" alone suffices to get this information, you have never listened to a pro golfer blab on and on about how good and sensitive he is "feeling" his putting stroke while objectively observing how far off the mark he actually is compared to what he thinks he is doing and what he is utterly unaware that he is doing. Golfers are particularly uneducated and unskillful at connecting "feel" to real anatomy and muscle activation and movements of parts -- probably one step lower than fifth graders in the gym dancing to the tune "Them Bones Them Bones!" The principal value of videotaping student golfers, according to veteran swing teachers, is not to inform the coach about the particular characteristics of the movement just executed, or even the student, but to convince the student that what he thinks he knows about his "good feeling" motion is completely incorrect in objective reality so the student will cease resisting the coach's directives of change. At least the student gets to understand that he is wrong, and now might listen to what the coach says he is actually doing and what he needs to change about that to quit making the same bad motion. So, for putting, adding a videotape record of the stroke motion that caused the error in results is one way to measure BODY ACTION. A more elaborate way is to use a biomechanical vest. Another is to add measurement reflectors or sensors to key body points (e.g., shoulders, elbows, wrists, hands, hips, base of neck, top of head, etc.) and to record the motion of these body parts to the end that the motion is understood in terms of cause and effect. Another is simply for the coach to actually know how bodies work when they move!! Biomechanics alone doesn't teach this -- it teaches the physics that governs the motion, not how the motion gets generated. That is the province of how the brain operates the body, and is called "neuroscience" and is not called "golf psychology".
Twenty-five years of hard-core neuroscience study and application of the science to golf putting skills teaches that the movement is generated by perceptions and intentionality of the external reality in the context of habits. Perceptions and habits guide the structuring of the movement (in neuroscience it's called "action"), not "groove the move" repetitions unconnected to intentions and perceptions. This is true even in the context of a simple "closed" skill like "the" putting stroke that is always the same set up and movement pattern apart from the "sizing" of the stroke for distance / force variables of this or that putt. The way the putter face looks in the stance below the face is always the same, seen from the eyes in the same location and height and angle of regard, with the feet and hips and shoulders and arms and hands and putter held the same way, and with the muscle tone always set the same (perhaps a wee tighter in challenging wind or long-ass putts or ball-below-the-feet lies) and with the same recruitment of body segments and muscles to start the stroke and the same balance and comfort and the same body-force management for good results when the stroke motion is underway. The PERCEPTIONS of all this, combined with the clear intentionality of the purpose of the stroke to help accomplish the MAIN goal of starting the ball online where aimed with good pace, places the golfer in the good prep for the movement that is the same all the time and is close to the ideal movement.
Without these same-as-always perceptions being attended to or at least replicated in fact by good habits grown over deliberate practice so the stroke is "sound" in design for both set up and movement pattern, the golfer is making a "casual" or "indifferent" effort that is unacceptable for really good golf. All strokes by folks without a carefully designed sound stroke set up and movement pattern are strokes that at best qualify as "casual" and whether the results will hew close to the intent is more of a crapshoot than these self-proclaimed "talents" admit. This sort of putting is what causes "streaks and slumps" without the golfer having the requisite "know how" to stop a slump IMMEDIATELY between the 4th green and the 5th green, and instead these "talents" wander in "Slumpland" for weeks and years, losing hundreds of thousands of dollars as the events relentlessly come on without the "talent" getting the problem sorted out with some gimmicky fix like the "claw grip" or a "belly putter" and a BIG HOPE.
Actually, if the golfer just KNEW to pay attention to the results compared to the intention, and also KNEW to pay attention to the body action for cause and effect, and further KNEW something about anatomy and muscles and how perceptions and intentions guide and structure movements, he could learn the skill by trial and error on his own. Absent this, he needs to be told about structuring the learning process to get these aspects out in the open. And he probably needs some objective recording of his body action, since he likely lacks accurate awareness no matter how fervently he swears he's good and sensitive about his "feel".
The stroke that I teach is one that simply and rather dumbly but easily sends the ball wherever the putter face aims, taking advantage of dumbed-down biomechanics to simply swing the putter according to default physics straight online across the toes in accordance with the alignment of the chest and shoulders mirroring the aim of the putter face, with a little attention to the firmness of the grip on the handle to prevent goofy putter designers from making putters that swing in the hands like bats coming out of the stroke plane -- something that is completely corrected by a firmness of the muscle tone in the lead hand on the handle at a 3 on a scale of 1 to 10, but putting instructors commonly ruin all this in the ignorant teaching to grip the putter "like a little girl holding a bird" and to "practice crochet by lamplight at night" to make sure the "exquisite hand-eye coordination of the dominant hand" will be equal to the incredibly fine demands of controlling the putter in the stroke that a REAL veteran must have. Such ridiculous ignorance in putter designs and instruction and the common beliefs of average golfers telling their buddies "how it has to be" is ruining golfers by the millions.
The parameters in the stroke I teach are: a) shoulder alignment matching putter face aim; b) arms hanging naturally and not reaching out or in to hold the handle but "docking" with the handle with the same-every-time distance of the feet and upper torso back from the ball; c) a natural hand-hang taking hold of the putter handle with appropriate form of the lead-side hand enclosing the handle (thumb flat on flat of handle) and minimum (not-less-than) pressure in the squeezing of the lead hand onto the handle (about a 3 on a scale of 1 to 10) with the rear hand helping prevent angle changes in the stroke motion but otherwise entirely subordinate to the lead hand for moving the stroke back and thru and for imparting the timing that matches the distance / force required by external reality. Those are the static parameters to pay attention to and measure and learn about.
Then there are dynamic parameters that cause good and bad results to monitor and learn about controlling. The main one is whether the shoulders and chest at impact are the SAME as they were at address, i.e., mirroring the aim of the putter face so that the default physics will send the ball squarely and solidly online without troubling the golfer much if any. The body motions that bother the chest / shoulder alignment are the head and the hips, and of course the upper torso also. The arms and hands don't bother the shoulder alignment much unless the golfer's timing is abrupt and violent and has a quality of "flailing" about it. In general, mild arms and hands actions challenging the shoulders are absorbed by the greater mass and inertial stability of the upper torso. But the head is a 16-pound bowling ball at the far end of a stick, and is unstable as "an inverted pendulum". Holding the face still in the stroke is done with the neck. Ordinarily, the rocking of the shoulders back or thru will cause the base of the inverted pendulum (at the base of the neck) to swing the head in the opposite direction of the stroke. In the backstroke, the head tilts / swings left and messes up the aim of the shoulders off the aim line of the putt. In the forward stroke, the rearward action of the head has an effect on the shoulders that is usually a bit too late to do any real damage. The BAD movement pattern is when in the forward stroke the neck veers towards the target and the head comes with it. This is the formula for a pull stroke, and the pull is what happens in about 90% of all strokes that don't send the ball wherever the putter face aims at address (there are other pull causes). As to the hips, if the hips follow the shoulders in the backstroke around to the inside, returning to the address orientation becomes a much bigger problem than necessary; and keeping the hips still at the start of the backstroke provides a biomechanical "cookie crumb trail" for the shoulders (Hansel and Gretel) to follow back out of the "forest of confusion" from the turn inside back to square before impact. Another ruination of strokes comes from the base of the neck swinging around or bobbing up or down thru impact. The shoulders get disarranged by this body part's motion.
So, stroke parameters are STATIC setup postures: stance, bend of upper torso, alignment of shoulders, hanging of arms and hands, distance back from the ball, elevation of base of the neck, grip form of each hand, and muscle tones in hands and arms, plus comfort and balance in the feet; DYNAMIC stroke movement parameters: stability of hips, stability of face and base of neck, mildness of tempo in motion, stability of base of neck in thru stroke to avoid swinging in direction of target or bobbing up or down, even if the neck spins the head back from the target a bit, and maintenance of shoulder alignment thru impact the same as it was at address while the putter head transits thru impact 3-5 inches, after which nothing matters as the ball is separated from the putter face.
There are also body actions that are secondary to the above fundamental actions (or non-actions), such as whether the hands thru the swinging between the feet remain a constant distance out from the body without veering closer or further away; whether there is independent action in the wrists; whether the forearms rotate the radius over the ulnar by muscles connected to the elbow; and others.
There is also FUNDAMENTAL timing properties of the body action to monitor and know about for causing good or bad strokes for distance AND LINE. It is a surprise to almost all golfers to hear and actually HEAR the following sentence: "Perfect rhythm CAUSES straight putts" for the minimalist stroke I teach. Even for complicated strokes taught by others, the following sentence applies: "Perfect rhythm makes BAD STROKES hard to cause by ill-advised patterns of motion." It's not my fault that golfers don't know what rhythm is, and don't know how to pay attention to it, although they swear they do know. Dave Pelz routinely uses the terms "tempo" and "rhythm" interchangeably, so that's pretty indicative of ignorance, and one would not expect a mere golfer to know the difference either, as proved in twenty-five years of direct experience demonstrating this beyond any serious question. The only golfers who even know the terms have different meanings are golfers with formal musical training, and even these golfers don't know how that matters in golf. To be brief about it, "tempo" is the quickness of the pendular swinging back and thru, timed from one top to the next just to quantify the naturally accelerating swing that peaks in velocity with acceleration zeroing out at minimum nothing right at the bottom point of the stroke. "Rhythm" on the other hand is the equality of the tempo back and thru, or more precisely the equality of the pendular swinging from one top to the next, whether that is back or whether that is thru.
In the putting stroke that artificially starts at the bottom of the stroke pattern from a deadness, the backstroke has a time-to-top that is the same as the swinging tempo, but the backstroke is actually "catching up" to the top-to-top tempo pattern of the swinging back and thru, to coincide with this basic tempo swinging only when the two patterns merge at the top of the backstroke. So the backstroke is more vigorous than the casual ongoing swinging of the tempo, but sort of blasts off to catch up the same way the anchor man in a relay race blasts off to match the oncoming third-leg racer as soon as he rounds the last turn coming at the anchor man, with the baton passing hands only when the anchor man has attained and matched the same maximum speed of the third-leg, so as not to slow the team down with a clumsy passing of the baton. the third-leg racer has the tempo from curve to curve, and the anchor man has to blast off halfway between the two curves and match the speed of the third-leg racer when the two reach the next curve. That's top to top tempo, matched from the start of the backstroke in the middle between the two tops. So THAT timing needs to be monitored in reference to the bottom of the stroke and to the top of the backstroke where the putter head coasts to a stop and transitions without pause to the downstroke accelerating to the bottom. The monitoring has to be of the tempo and the rhythm, and I've never even heard of a designer of a putting monitoring technology who knows anything at all about the above in 25 years of very diligent proactive searching.
In fact, the designer of the training aid Tour Tempo first designed the swing aid based upon counting frames of swings at different tempos but with a 3-to-1 rhythm in all cases regardless of the "quickness" of the swinging. He then thought he could design one for putting and we spoke about it over the phone for two hours, with me patiently explaining the neuroscience by which the human body gets trained to only one unique natural tempo of about 1 Hertz or one top-to-top swing of the arms and legs with metronomic physics in about one second, depending solely upon the length of that person's adult-sized arms and legs (which incidentally aren't all that unique and special to any one person, as almost all adults have closely the same one unique tempo for all practical purposes). Further, I explained in great detail why the natural "rhythm" for the putting stroke is optimally the same as the engrained 1-to-1 rhythm evident in the back-and-forth swinging of the limbs, since in the full swing POWER is generally the priority and MAXIMUM POWER the base pattern, compared to putting where finesse in the variation of power is required. For the full swing, the common pattern is FULL POWER every club, and each club goes only one distance. In putting, one club goes a thousand distances. That happens optimally and naturally only when the tempo is stable and the rhythm is 1-to-1. A metronome never changes tempo just because the SIZE of the stroke got larger or smaller (a fact from physics that golfers almost never have familiarity with or think of in connection with golf). What DOES change with changing size of stroke is the velocity of the stroke at the bottom of the swing. In physics, the ONLY thing that really matters to distance control is the velocity of impact of the fixed and familiar mass of the putter head thru the mass of the ball. And given a stable tempo, ONLY the SIZE fixes one and only one VELOCITY. So for putting with a stable tempo, SIZE is the ONLY THING the body needs to get right in the backstroke and then repeat in the 1-to-1 rhythm for the thru-stroke. Period. The "body neuroscience" is wired to this size-velocity connection most strongly only with the one natural tempo and the simple 1-to-1 rhythm of the limbs. Having explained all that to the Tour Tempo non-teacher, he said he understood that he needed to include a "largo" tempo in the putting trainer at about 60 beats per minute or 1 Hertz. I said he "absolutely" had to include that or the device was unusable for training really good strokes. And then he made what he wanted to make ... He voted not to go against the common herd that might think the largo tempo was too unusual since MOST GOLFERS DON'T USE THIS TEMPO, and made a device that starts at about 75 beats per minute, 25% too quick for the base of human movement in the brain for nearly all adults, and also the tempo approximated by some of the greatest putters in the game (Loren Roberts' "tempo" is just shy of 1 Hertz or 1 second at 0.96 seconds from top to top, an so is Ben Crenshaw's). Well, dumbo Tour Tempo guy, "most golfers" don't use the largo tempo because they don't know they should. Most golfers don't do what Loren and Ben do, either, and that's why they are NOT AS GOOD as Ben and Loren. The Tour Tempo therefore trains the herd to stay in the herd, putting the herd "average" so-so, and not the superlative level that the few non-herders get to. So much for technologists knowing how to design training devices! What a waste for all golfers buying this guy's technology, made in such a stupid fashion. For the SAM Putt Lab to mess up stroke training is one thing, but for a non-teacher to mess up tempo and Rhythm is disastrous. Don't buy or use the Tour Tempo for putting.
I'm waiting for Daddy Bigbucks to realize the potential of getting golf putting technology done well is WIDE OPEN and has NEVER BEEN DONE WELL. Those who think otherwise refuse to face the issues I raise, or ignore them knowingly and willfully for the sake of getting cash from the golfers in a BIG EXPENSIVE SPORT. So far as I can tell, there is no one designing golf putting technology who bases the parameters on the skills. The BEST that comes out if something some unknowledgeable designer claims can be used by any teacher to measure whatever the teacher thinks needs measuring. That, also, is pure baloney.
In BIG PHYSICS, like the $10-15 BILLION dollar Hadron Collider in Cern Switzerland, no experimentalist or physics engineer would DARE purport to design the technology without being guided by the theoretical physicist telling him what to look for with the technology. At Cern some years ago, Richard Feynman "visited" for the first time in his life, and all the physicists that built the thing stood up and applauded and told him he taught them how to design the collider and what to use it for, because of his theories about the nuclear forces. Understand the skill or don't design the training aid, folks. Just stop, please. (That's not going to be enough to get them to stop, now, is it?)
I know this qualifies as a "rant" but it really is necessary in light of the harm the bad ideas about all this are "blessing" in golf.
Putting Coach and Theorist