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Thread: For Duffey

  1. #1

    For Duffey

    Mike,

    Let me ask you this question point-blank: What's your motivation for being here?

    If you'll look at the 100's of threads on this site, not sure any are devoted to biomechanics. We have become very skeptical about biomechanics because we don't trust the quantitative information that's coming out from it. Why not stay with the Manwithsmartfriends who openly worships “scientists”?

    On FB, in a discussion of my release styles, a TPI guy with data captured at 240hz was used to discredit the qualitative work I've done. I have studied the release at 4,000 to 10,000 fps and can tell you that 240hz is not sufficient to detect these fast micro movements in the impact zone. Thus, quantitative biomechanics performed with data acquired at inadequate sample rates will lead to incorrect conclusions. No one said a word about the low sample rate at the other sandbox. Truth and science obviously take a back seat to bias.

    On another note, I understand the biomechanists would be equally skeptical of those (golf coaches, players) that study 2D video. Thus biomechanists want to verify what people see. But here's my opinion on where the “scientific process” gets corrupted. Biomechanists would need to understand the fundamental (qualitative) characteristics of a golf swing ? So biomechanists find "golf experts" to tell them what to look for or what is important in the golf swing. This is a critical step in the process.

    So, which “golf experts” have been consulted/engaged by the biomechanics community to educate them on the finer points of the swing?

    TPI's golf expert is Dave Phillips who was a longtime assistant of David Leadbetter thus his view of the swing is much the same. Not that there's anything wrong with that, but do you realize Leadbetter has drifted from the mechanics he once taught when Faldo, Price, Denis Watson were around (perhaps with confirmation from scientists)? Where his students once dominated the men’s tour, he has become mostly a teacher of female tour pros. While he may have the top female pros in his stable, it is questionable whether he is improving them or not. Look at Leadbetter’s highest profile female student, Michelle Wie, the poster child for going from elite as a teenager to average LPGA pro. Then, there’s Gary Gilchrist, once head of the Leadbetter junior academy and now operating his own academy. Armed with the same Leadbetterian knowledge of the golf swing and much self-assurance, has now coached former #1 player in the world Yani Tseng into a player struggling to make cuts. Phillips is cut from the same cloth. You think the results will be any different?

    I also devoted over a decade to learning the Leadbetter method and in the end I learned that at the very heart of his method was a "stall and flip" swing. In quantitative terms, it matched up well with the proximal to distal theory. Thus, in my view, the Leadbetter methodology and these emerging biomechanical analysis systems being prepped for the marketplace was a marriage made in heaven. In a way, the golf teaching world and biomechanists validated each other’s findings. Biomechanists jump on board the fast moving train and it becomes big business! Never mind that the poor mechanics are destroying golf swings, it’s all about the Benjamins!

    So what's to stop that train from derailing more top players and amateurs? Clearly Manwithsmartfriends is not someone who has a scientific mind. He's an excellent marketer. He won't challenge the science and/or be able to verify the science. He's a science "yes man" because it serves his purpose of selling himself as a gatekeeper of knowledge. But you do not further the knowledge that would help golfers this way. Jeffy and I are the lonely voices of reason in a world of golf science that's stopped asking questions. And, what we have learned so far is that when questions are raised the tallest nail gets hammered.

    http://www.youtube.com/watch?v=PjX4NLdiB1k

    Since you spoke of Zatsiorsky, in this interview he talked of going to a lecture given by a Russian coach that devoted his life and spent all his money on 16mm camera, shooting movies then developing the film to gather many pictures to study track/field events (about 7:25 into the interview). The coach showed many different pictures and the young students came away with knowledge gained from the many years of careful observation and deep study by a very experienced coach.

    In the world of golf, it appears that this critical step of extensive, careful observation has been skipped. Where are your years of study with high speed cameras of elite players? I’m sorry but, in my opinion, your quantitative database of 0-10 handicap players does not constitute extensive observation of elite players.

    At this point, you have a choice; study 2D video and understand elite level golf swings then use that knowledge to revamp the critical software codes to improve the quantitative biomechanics or continue to search for insight guided by so-called golf swing coaches who are really only experts at self-promotion and marketing.

  2. #2
    Succintly put. You'd still have to admit that Leadbetter's influence on the "academic" world of golf is just ridiculously pervasive. You can't fault his marketing skills. Manzella still needs to learn much more.

  3. #3
    Mike Duffey Guest
    There were two things that initially lead me to this site - Jeff sent me a facebook friend request, and I then found out that he had this site. Also, you raised some interesting questions within the FB group and I found out you also posted here.

    When the conversation ended on FB, I thought I would try to continue some of it, and this seemed to be the only venue for that. I'd be happy to learn more about your teaching methods and how you use 2D video. Hopefully there would be an interest in finding out what 3D can (and can't!) do, and there could be an exchange or information and ideas.

    I don't claim that 0-10 handicap players are elite, in fact I believe I described them as being good but not great, and one of the good things about looking at them is seeing what they do well AND what they don't do well.

    And once again, I am not a coach. I do not pretend to be a coach, and I basically do not give swing advice. I hope you understand that I study the swing, and try to work with actual coaches to help them learn and maybe do their jobs better. Much like many other tools, including 2D video - some coaches have found 3D to be helpful, some choose to use 3D in on a case-by-case basis, and some choose not to use it at all.

    Getting to your example - The Russian coach probably did an outstanding job with 2D video. Zatsiorsky began using 3D found that it can be a useful tool for explaining things, especially those that are difficult to see on 2D video. Both can serve a role.

  4. #4
    Mike Duffey Guest
    And for the record, I assume Manwithsmartfriends is your title for Brian Manzella. I am not with him, so there is not "stay with him." He does not particularly influence my professional decisions. Like anyone else, if he had a strong suggestion for a research topic or offered an opportunity for something along those line, I would listen.

  5. #5
    Quote Originally Posted by Mike Duffey View Post
    I don't claim that 0-10 handicap players are elite, in fact I believe I described them as being good but not great, and one of the good things about looking at them is seeing what they do well AND what they don't do well.

    And once again, I am not a coach. I do not pretend to be a coach, and I basically do not give swing advice. I hope you understand that I study the swing, and try to work with actual coaches to help them learn and maybe do their jobs better. Much like many other tools, including 2D video - some coaches have found 3D to be helpful, some choose to use 3D in on a case-by-case basis, and some choose not to use it at all.

    Getting to your example - The Russian coach probably did an outstanding job with 2D video. Zatsiorsky began using 3D found that it can be a useful tool for explaining things, especially those that are difficult to see on 2D video. Both can serve a role.
    I may be mistaken but it seems you finally give some indications that you do happen to make some form of value judgement in your very objective, fact-based work. So Mr Gradgrind, how do you decide which are the things "they do well" versus the stuff "they don't do well". Would you then please list them out for me one by one so I know?

  6. #6
    Mike Duffey Guest
    Piggy,
    Are you asking for a complete and exhaustive list of possible faults in the golf swing? I believe that is not possible or realistic, but perhaps you are able to do it. Please go ahead.

  7. #7
    Quote Originally Posted by Mike Duffey View Post
    Piggy,
    Are you asking for a complete and exhaustive list of possible faults in the golf swing? I believe that is not possible or realistic, but perhaps you are able to do it. Please go ahead.

    In case other mature, self-respecting adults are looking and listening, I will just clarify that I am not asking you for a "complete and exhaustive list of possible swing faults in the golf swing." Geez, what happened to the No Child Left Behind Act?

  8. #8
    Mike Duffey Guest
    Quote Originally Posted by Piggywedge View Post
    how do you decide which are the things "they do well" versus the stuff "they don't do well". Would you then please list them out for me one by one so I know?
    Piggywedge,
    The quote above reads to me as if you are asking for a complete list, hence the "one by one" instruction. Clearly I am not understanding you, could you give me an example of what you do (or your instructor of choice does) and I will follow that?

    Thanks.

  9. #9
    One by one did not imply exhaustiveness. Here is a link to a micro-move article http://www.aroundhawaii.com/lifestyl...lf-swings.html. I certainly am not expecting you to write a detailed, well written article. But a list of what you feel are "the things they do well" and the things "they don't do well" with a line of reasoning will be very appreciated.

  10. #10
    Mike Duffey Guest
    OK,
    Honestly, I think you are still confusing what I do with what a swing instructor does. I don't pick things out and work on them with golfers, I spend much more time looking at group data and then drilling down to look at individual differences. But here are two examples:

    As a very general rule, I would look at ball flight information before a 3D report. If that looks good, it is fun for me to go back and look at swing characteristics. For example, I'll look at transition and peak velocity sequence. As a general rule, I think having the typically discussed 1-4 sequence helps the golf swing. I certainly believe that it is not an absolute requirement. IF either sequence is not good, I try to find what that golfer did to get good impact.
    Why: There is general agreement that in motions where distal end velocity is the goal, we usually see a proximal to distal acceleration/velocity sequence. I believe that theory is sound.

    As a second example, I don't like seeing a swing that is substantially "over the top", meaning roughly 5 or more (definitely 8 or more) degrees out to in path.
    Why? I think (and physics tells us) when players are that far off plane, there is a loss in distance for any given swing velocity.

    I still think the potential list of "don't likes" is endless. Also, I picked my answers before reading the link to what Kelvin wrote. It is coincidence that I chose swing path.

  11. #11
    I understand exactly what it is you do. It is fine to do data collection and spot out the trend. That is, at an elementary level, the gist of the scientific method. Nevertheless, except for the lab assistant, objective observations do then require that insightful interpretations be made for them to be of added value. I do therefore thank you for your response. Please feel welcomed to post other "don't likes" as well as "likes".

    Now, the saying goes, there is the scientific method and then there is the scientific method, and similarly, there is data and then there is data. However, it is always easier to have a conversation based on convened baselines, within the confines of a method and procedure. We may discuss methodology at another time, or in another thread. For now let's stick with what you have, and what Kelvin has and assume a world where a seeming duality exists.

    For Kelvin, there is a second firing of the legs, for you there is the proximal to distal acceleration. From my perspective this may not be so irreconcilable. Perhaps proximal/distal acceleration/velocity ratios may be key. But that is not our fight just yet. Allow me the privilege of picking out our first theme of discussion.

    OUR CURRENT THEME: THE OUT-TO-IN, OVER THE TOP SWING

    I find interesting what you define as "over the top", as this is of an interest to the majority of amateurs who hit a weak slice. Clearly for such golfers, the lost in distance may be attributed to swing path. However, let ramp up the notion and add a few more complications to bring it closer to the world of elite golfers.

    In your observation, can a swing be flat and still out to in? Looking conversely, are all out to in swings over the top - in other words is the statement " The swing is over the top if and only if the corresponding swing path is out to in" TRUE? Do you concern yourself with the causes of an over the top swing or do you simply relay the system's diagnostic?

    Finally, I've been scrambling tight without success to find the diktat that establishes the shot distance to path relationship. Would you please point me in the right direction?

    Personally my piqued interested in the over the top swing peaked after seeing Pat Perez play at a tournament.

  12. #12
    Mike Duffey Guest
    As it is late, I'll start with the path:shot distance relationship and hopefully get to the other deeper topics tomorrow.

    The 'distance' of a shot is almost always presented as the length the shot travels toward the target (except for shots like the particularly famous shank in this year's U.S. Open). And, of course, the goal is to hit the ball 250 yards toward the target as opposed to 250 yards in some other direction.

    Let's assume for now all other impact conditions being equal (face square to target, center contact, AoA, etc.): it is the linear velocity of the club that determines the linear velocity of the ball after impact. Velocity, rather than speed, is important because it has both speed and a direction. Let's say (with a 0 path and 0 face impact) you can generate a club head speed of 100mph and a smash factor of 1.5, thereby creating a ball ball velocity of 150 mph. That same shot with a path of 10 degrees left and 0 face to path will still have a ball speed of 150mph, but it will be ~147 mph down the line and ~26 mph to the left. Not a big loss in speed or distance toward the target, but that shot is going to be well left. So we now change face angle to impart side spin and change the horizontal launch angle to bring the ball back closer to the target line. That reduces down the line distance in a couple of ways: 1. the side spin, while 'improving' the landing location of the ball will probably act to slow the ball. 2. You are now imparting a glancing blow on the ball. This will no longer result in a smash factor of 1.5, so your ball launch speed will decrease (stretching the example, having the face 90 degrees open will not create any down the line velocity).

    So, as a short summary, keeping path within 3 or so degrees should have an almost negligible influence on the velocities discussed above, and may be a more 'consistent' shot for a player. As we get to larger path numbers, I believe that we reach a point where the loss in velocity/distance will start having a negative effect on scoring.

    I did, by the way, enjoy the use of the double (phonetic) peak. Perhaps it was a carefully crafted homage to the pelvis velocity double peak discussion?

  13. #13
    I see you do enjoy poetry. That's never a bad thing in the realm of the scientific method. Especially when we have that and the scientific method.

    It is getting late indeed so I will make a quick comment rather than a protracted commentary. It's not uncustomary to challenge the scientific method by questioning the ceteris paribus assumption. And so that will be the first challenge. Since in golf, nothing happens with all things being equal, it is entirely possible (and likely) that some golfers physically generate higher impact clubhead speed (magnitude) with an out to in swing path, while others with an in to out swing path. Tough in those cases to say "well if these guys managed a square swing path, they would hit it further..."

    I would also suggest that you take a serious look into ROC (rate of closure) and its effect on ball flight. I don't know if you use a Trackman in your business but if you do, that is something to be aware of. The Trackman does an extremely poor job of deducting club face and path through its algorithms and over-simplifies impact. Although this is still a contentious subject in some circles, Trackman itself has given indications that the ROC is a factor in ballflight. For the sake of science, your business must be ready to adjust your understanding away from the so-called new ball flight laws.

    You didn't respond to my other important question however, concerning the over the top swing, how it's defined, the limits of those definition and what you perceive to be the root of the over the top -> perhaps how one might proceed to correct it (how might your favorite instructor help one diagnosed with an out to in path).

    And on the topic of the shank, my non-scientific guess is that an out to in club path would alleviate shanking woes enormously.

  14. #14
    Mike Duffey Guest
    Quote Originally Posted by Piggywedge View Post
    I see you do enjoy poetry. That's never a bad thing in the realm of the scientific method. Especially when we have that and the scientific method.

    It is getting late indeed so I will make a quick comment rather than a protracted commentary. It's not uncustomary to challenge the scientific method by questioning the ceteris paribus assumption. And so that will be the first challenge. Since in golf, nothing happens with all things being equal, it is entirely possible (and likely) that some golfers physically generate higher impact clubhead speed (magnitude) with an out to in swing path, while others with an in to out swing path. Tough in those cases to say "well if these guys managed a square swing path, they would hit it further..."
    I definitely agree, and I do understand the potential pitfalls of the ablative absolute. I use it to isolate effects, but you are quite correct that if a golfer changes one thing within a swing, others are almost certainly going to change. My thought is that once you get somewhere between 5 and 10 degrees right or left, the loss of return (down the line distance) on investment (farther from zero path that improves impact conditions) becomes too great for high level golfers - those shooting par or better at competition distance tees.


    Quote Originally Posted by Piggywedge View Post
    I would also suggest that you take a serious look into ROC (rate of closure) and its effect on ball flight. I don't know if you use a Trackman in your business but if you do, that is something to be aware of. The Trackman does an extremely poor job of deducting club face and path through its algorithms and over-simplifies impact. Although this is still a contentious subject in some circles, Trackman itself has given indications that the ROC is a factor in ballflight. For the sake of science, your business must be ready to adjust your understanding away from the so-called new ball flight laws.
    One of the reasons I have not looked at ROC is that we do not put markers on the club head and we only collect at 250Hz. Because of those collection conditions, we calculate rotation for the grip through mid-shaft. I believe that ROC might have some higher frequency content or differences between club head and grip movement that we could miss. A higher ROC would contribute to club head velocity, but it would likely increase the requirement for very good timing in the swing, so it is a cost/benefit question that would be interesting to examine. I just don't feel we can do it well right now.

    We do use TM now (FlightScope until this year), I posted some comments in a different thread.

    Quote Originally Posted by Piggywedge View Post
    You didn't respond to my other important question however, concerning the over the top swing, how it's defined, the limits of those definition and what you perceive to be the root of the over the top -> perhaps how one might proceed to correct it (how might your favorite instructor help one diagnosed with an out to in path).
    Ath this time and for the purpose of this discussion, I'd call any out-to-in path over the top. I don't love that definition, in fact I'd prefer to expand it so that it covers a more specific set of conditions; I'd say I am passively looking for a different definition. If you or someone here has one that you particularly like, I'd enjoy listening. I think there are several components that can lead to it, and that is part of why I don't like my current definition. My feeling is that over the top should be a term for a set of definable swing conditions that typically lead to decreased performance, whereas I think an out-to-in path of 1-2 degrees might be very, very playable.

    Quote Originally Posted by Piggywedge View Post
    And on the topic of the shank, my non-scientific guess is that an out to in club path would alleviate shanking woes enormously.
    Interesting. I have heard much more support for the in-to-out path as compared to out-to-in but I haven't heard what seemed like an open and shut case either way. I'd listen.

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