Roger Federer and Modern Technique

Discussion in 'Tennis Tips/Instruction' started by JohnYandell, Mar 19, 2011.

  1. 5263

    5263 G.O.A.T.

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    Not exactly the proper context. MTM uses the approach you recommend on page 12 of "visual tennis" of mastering the model stoke, then as feel is developed, using feel, along with some suggestions, to make all the little adjustments required for most Fh situations. Maybe you don't still do it the same way currently, but that aspect of the book was right on target IMO. A nice basic model is the place to start and develop feel from experience.

    On the other hand citing numerous variations and situational compensations is probably more of a wasted exercise for most players, as players are going to develop feel differently alone with having varied personal strengths to work from in their game. I think your earlier approach of using a model is better advice.
     
    Last edited: Mar 23, 2011
  2. 5263

    5263 G.O.A.T.

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    So you agree that the arc is tighter around contact?
     
  3. toly

    toly Hall of Fame

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    If the long axis of the racquet and straight arm is the straight line (during impact) and the hand can rotate, the speed of the point of contact can be calculated according to next formula
    V1 = Ѡarm*50” + Ѡwrist*25”.
    If the wrist is locked the racquet speed would be around
    V2 = Ѡarm*50”.
    Obviously, that V1 > V2. Tiw moving wrist allows using shorter swing.
     
  4. julian

    julian Hall of Fame

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    A meaning of "tiw"

    Please explain a meaning of "tiw"
     
  5. toly

    toly Hall of Fame

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    Tiw = That is why.
     
  6. 5263

    5263 G.O.A.T.

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    I agree that you can't make too much from only one vid, but you couldn't ask for a more clear depiction of what Modern instruction teaches with the crossing motion. Others may teach this too, although i don't know who. Many get misdirected by looking at the racket tip, but it's the hands we are taught to use for reference and to navigate the action. From 4:01 to 4:11 it gives the incredibly clear depiction of how the hand starts across right before the instant of contact, essentially throwing the racket head out thru and across the ball with their change of direction. (can't see the "up aspect" here but can in other parts)

    http://www.youtube.com/watch?v=pPLmCqGIotM
     
    Last edited: Mar 24, 2011
  7. JohnYandell

    JohnYandell Hall of Fame

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    My point is (obviously) not to have models. My point is to identify the correct ones. I think the high speed clip I posted is closer to what I think should be taught as a basic drive than the shorter extreme wiper in the fuzzy balls clip.

    Toly: don't think you understand what I mean by extension. I am talking about the distance the hand travels forward away from the body--around whatever arc you want to call it--it's the point that what you posted shows quite well. Look how long the arm stays straight.
     
  8. spacediver

    spacediver Hall of Fame

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    Ok that's good to know. My concern is that the reference points (for key joint positions) aren't consistently tracked. When you have actual physical markers, or sensors, on the body, the issue is simple. Without them, it seems like it can be a bit of a hairy issue to reliably track the positions.

    This is especially so when you have obscuring clothing etc. How can the APAS system infer the position of the shoulder joint, for example, just based on raw video?
     
  9. JohnYandell

    JohnYandell Hall of Fame

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    You need to take a class in biomechanical analysis if you want to challenge all this. It's why they use 6 cameras. The technique is very well accepted and considered accurate.
     
  10. Lawn Tennis

    Lawn Tennis Semi-Pro

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    Thank you everyone (not just the two quoted) for your input.

    It seems that everybody agrees to some extent that the (preferred) poised position of the racquet/wrist is superior to laying the wrist back prior to the forward motion.

    To me, the preferred method is the natural way of hitting a tennis ball. In other words, if we weren't required to keep the ball in the lines, one would automatically and always use this fluid form (i.e., the necessary control element of tennis enters our head and customizes the motion for some at times).
     
  11. spacediver

    spacediver Hall of Fame

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    ok that's reassuring. I'll take the default assumption that the technique is accurate unless I discover otherwise. I remember reading another paper (I think it might've been by Bruce Elliot) where they used a similar technique. Was a bit too technical for me to understand, but I guess the APAS system is similar.
     
  12. JohnYandell

    JohnYandell Hall of Fame

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    That's the way Bruce did all his work. Great guy btw and one of the people in tennis open to the evolution of information.
    Was with him at a few conferences.

    Yeah the debate might be over the accuracy of the hard measurements and the possible error factor. But the visual representation is great! Love the overhead view to show extension.
     
  13. Hewex

    Hewex Semi-Pro

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    Isn't the evolution of technique driven by equipment? Teachers and players adapt the strokes to how the equipment reacts at impact in order to maximize the results. In golf, going from hickory shafts to steel meant a technique adjustment. The same would be said for going from wood to graphite in tennis. So while the current modern technique is the standard, it likely won't always be such.

    Fair statement or no?
     
  14. tennisplayer

    tennisplayer Rookie

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    One more question on extension (sorry if this point is obvious to everyone): does this mean that one should try to hit with a straight arm as much as possible, since that provides the most extension? If not, what does extension mean when hitting with a bent arm? Thanks in advance.
     
  15. JohnYandell

    JohnYandell Hall of Fame

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    No good question about the hitting arm. With the double bend structure the bend is just maintained throughout or may shorten at the elbow after contact with a wiper.

    But the best way to learn the drive is with the point where the left hand reaches the side of the torso, right at about eye level and good spacing--up to two feet depending on your body and the shot--between the hand and the torso.
     
  16. toly

    toly Hall of Fame

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    Hi John,
    What do you think about hypothesis: Channeling kinetic energy from one part of the body to another? Who is inventor? Is there any proof that this hypothesis is right? IMO that is absurd idea!!!
     
  17. spacediver

    spacediver Hall of Fame

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    toly, suppose I use my leg to kick my arm up into the air.

    Before I kicked my arm, my arm was stationary, and had zero joules of kinetic energy.

    After kicking it, some of the energy from my leg gets transferred to my arm.

    This is a trivial example, but it's an example of how kinetic energy can get redistributed throughout the body.
     
  18. JohnYandell

    JohnYandell Hall of Fame

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    Toly and SD,

    You are asking the wrong person with only a layman's understanding. But I am pretty sure there is not some special magic kinetic force in the universe that moves around the human body that we need to learn how to measure with some special kinetic energy meter...

    Brian Gordon agrees with you Toly, and says that, while the concept has use, what really is happening is that in each stage of the stroke, the body is positioning itself to allow it to move in the most efficient way that contributes to or generates racket head speed.

    Each movement sets the stage for the next. For example, the leg drive helps to force the arm to externally rotate, thereby enhancing the critical internal rotation, etc...


    JY
     
  19. toly

    toly Hall of Fame

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    Hi spacediver,
    IMO channeling energy is controllable energy transfer from source (transmitter) to receiver. For instance, from car engine to left front wheel only. Modern car has special mechanisms to do so. Our body has nothing like that. Your example is example about uncontrollable energy distribution. It has nothing to do with channeling energy.
     
    Last edited: Nov 13, 2011
  20. toly

    toly Hall of Fame

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    John, thank you so much. At least one person agrees with me.
     
  21. spacediver

    spacediver Hall of Fame

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    the term "channel" is a metaphorical one that implies energy is transfered, in a somewhat controlled manner, from one thing to another.

    In the case of tennis strokes, there most certainly is controlled transfer of energy from one body part to another. This is what the serve motion is based on!

    The kinetic energy starts out being concentrated in the lower body and torso, and by the end of the motion, it is highly concentrated in the forearm, hand and racquet.

    Brian Gordon spends a good deal of time discussing passive torque, or motion dependent effects, which is a highly related concept.
     
  22. toly

    toly Hall of Fame

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    If I jump into air with speed V, it means that all particles of my body get the same speed V, because the body is firm enough frame (if it is not falling apart). It is natural uncontrollable process. There is no concentration of energy. Every muscle should produce some force and work hard to create kinetic energy.
    We discussed this problem so many times and I think I’m just unable to convince you. I’m really sorry.:(
     
    Last edited: Mar 25, 2011
  23. spacediver

    spacediver Hall of Fame

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    the body is not a perfectly rigid body. You can analyze individual components, while still accepting that the overall kinetic energy remains constant (unless loss to outside objects, or added to by chemical energy in the muscles).

    Anyway, momentum, rather than kinetic energy, may be more appropriate for this discussion. Perhaps I can tap your intuitions on the issue with the following question.

    Do you agree that momentum can be channeled from one part of the body to another?
     
  24. bhupaes

    bhupaes Professional

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    Hmm... let me make an attempt to explain it as I see it.

    Ultimately, there is a mechanical reason for energy to be transfered from one part of the body to another. Consider the FH stroke. When the arm accelerates forward and the wrist lags, part of the kinetic energy of the arm goes towards pulling the wrist back, and so gets stored as potential energy in the stretched muscles of the forearm. When the wrist "releases", this potential energy (plus any active contraction of the forearm muscles) contributes to the kinetic energy of the hand/racquet.

    Similarly, the arm benefits from the kinetic component(s) preceding it in the chain. At least, that is my layman's understanding of how the kinetic chain works.

    If we were to accept the thesis that every part of the body is independent and is not affected by other parts, we are left with the conclusion that the wrist must be solely responsible for creating the final racquet velocity, which we know is not possible.
     
  25. toly

    toly Hall of Fame

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    I do agree.
     
  26. JohnYandell

    JohnYandell Hall of Fame

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    Toly, Two at least. Brian Gordon and his disciple (me.)
     
  27. spacediver

    spacediver Hall of Fame

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    There's a much more direct and simple transfer mechanism. You don't need elasticity and the like - those can be looked at as "bonuses" - a simple joint will allow transfer of angular momentum from one limb to another.


    Stand up, keeps your arms loose by your side, and swivel your torso to the left and right. You'll notice that once your torso stops swiveling (due to anatomical constraints), the momentum gets channeled into the arm, causing it to swing "by itself". This requires no special store of potential energy, or any stretch shortening cycle or the like - simple basic physics can explain this behaviour.
     
  28. bhupaes

    bhupaes Professional

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    Agreed, and this the obvious and direct mechanical link. However, to explain the final energy build up in the racquet - at the levels we see in accomplished tennis players (along the lines of the energy graph sennoc posted) - I believe we will need to take into account the "lag" effect also between the links. Hitting with lag is, IMO, fundamentally different from hitting without lag. Looked at another way, the lag effect increases the runway for accelerating a link.
     
  29. spacediver

    spacediver Hall of Fame

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    aye, I agree.
     
  30. pushing_wins

    pushing_wins Hall of Fame

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    is that really RF?


    do you have any regrets about your business model? FYB has copied your idea and is now laps ahead of the competition. According to some website value estimator, FYB is worth 10 times the value tennisplayer.net.



    another thing i have noticed. will's face is all over the internet, he is silky smooth in front of the camera. the only video i found of you is this.
    http://www.tennisresources.com/inde...ail&basicsearch=1&media_name=&rv=1&vidid=3599
    with will's delivery, he could sell ice to an eskimo. maybe thats an area you can improve on. your thoughts?
     
    Last edited: Mar 26, 2011
  31. pushing_wins

    pushing_wins Hall of Fame

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    stop sucking up

    edit
    --------------------------
    ;)


    couldnt agree more with balla's point
     
    Last edited: Mar 26, 2011
  32. Djokovicfan4life

    Djokovicfan4life Legend

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    Out for attention again, I see?
     
  33. spacediver

    spacediver Hall of Fame

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    what the hell's wrong with you pushing?
     
  34. Djokovicfan4life

    Djokovicfan4life Legend

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    He's trashed FYB as well, just out for trouble.
     
  35. chico9166

    chico9166 Guest

    Pushing, you are so selfish. The probable reason why Will, Yandell, and others don't contribute much on this forum, is because of people like you. Those who contribute nothing but to try and embarrass/humiliate. (and in your case, lamely) Why would they? They have nothing to gain. I for one, enjoy the thoughts of guys like this, and find it disappointing when people like you ruin it for all of us. You are not clever, amusing, or insightful----only self serving. Get your kicks somewhere else.
     
    Last edited by a moderator: Mar 26, 2011
  36. 5263

    5263 G.O.A.T.

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    Pushing might be slightly aggressive in spots here, but is making some very good points. JY is often much more aggressive towards posters. Balla in that post was careful to get JYs perspective correct, and just as careful to be incorrect on the opposing view point. It is fair to call that out as sucking up. Balla is clearly versed well enough to know that MTM never, ever says just "hitting across".

    Also pushing's points about fyb's public presence are very much on target. Wil is much more tolerant of folks who may disagree with his info, and makes a effort to find a useful common ground. Wil seems to realize that that debate can be tool for better understanding. Jy is much less respectful of dissenting opinions, and even his paying customers on Tp. Funny thing is that back in the day when Tp was just starting, JY was a master of taking the higher ground without sounding condescending.
     
    Last edited: Mar 26, 2011
  37. mightyrick

    mightyrick Legend

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    vBulletin would be really good if it had something akin to a "killfile" that a person could add to their profile. I just have no desire to even read certain individual's posts.
     
  38. 5263

    5263 G.O.A.T.

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    there is a block feature on this forum so you don't have to read from posters you pick.
     
  39. dozu

    dozu Banned

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    it's called the 'ignore' feature... works just fine.
     
  40. chico9166

    chico9166 Guest

    No, there is really never anything constructive in his posts. If you research them, it's obvious to most. Look, everyone has an opinion, and things can get a bit heated (like you and Yandell) but at least it's information that people can pick and choose from. It's concrete info/thoughts that can be used. That's all good in my book. Like this thread.

    Pushing doesn't bring anything to the table. His agenda is clear. My opinion.
     
    Last edited by a moderator: Mar 26, 2011
  41. SystemicAnomaly

    SystemicAnomaly G.O.A.T.

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    ^ I'll 2nd this assessment from chico.





    .
     
    Last edited: Mar 26, 2011
  42. 5263

    5263 G.O.A.T.

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    Ok, I'll defer to your experience; especially in light of your well stated opinion and experience with this history.
     
  43. JohnYandell

    JohnYandell Hall of Fame

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    Oh that is funny, pushing is now an internet business analyst. My only comment to people is that I wouldn't make any substantial bets or investments based on his assesments of the value of the two sites, at least if revenue is any determination of value. And pushing thanks for your concern about any regrets I may have, but no things are ok.
     
  44. mightyrick

    mightyrick Legend

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    Ah, I found it in the profile section. A little difficult to see, but I got it. Good deal.
     
  45. spacediver

    spacediver Hall of Fame

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    Whether or not this is true, I don't see any example of this behaviour in this particular thread.
     
  46. toly

    toly Hall of Fame

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    When we swivel torso to the left, because of the inertia the arm lays back. It means, the arm moves mostly upward and hence collects potential energy. If we stop torso rotation, the arm starts moving like pendulum. Once again there is no energy transfer, but just conversion potential energy to the kinetic energy.
     
  47. spacediver

    spacediver Hall of Fame

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    No toly, I'm talking about the way in which the arm continues to swing horizontally. This is very basic physics - nothing special or magic! This channeling of momentum would occur even if the joint didn't allow the arm to lag behind.

    This is how a whip works - momentum gets channeled from the large heavy part of the whip to the tiny end of the whip. The body can approximate a whip.
     
    Last edited: Mar 26, 2011
  48. pushing_wins

    pushing_wins Hall of Fame

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    i asked can will hit the ball.

    in response, he posted some videos.

    imo, will sure can hit the ball.

    i wouldnt consider that trashing.
     
  49. pushing_wins

    pushing_wins Hall of Fame

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    sorry to derail the discussion

    i had a discussion with my friends about monetizing tennis website last nite, so it was fresh on my mind. Specifically, how will was able to pull ahead of the websites who established themselves first.

    will is a terrific public speaker and marketer.

    i wanted hear it straight from the horse's mouth. thats why i m here.
     
    Last edited: Mar 26, 2011
  50. pushing_wins

    pushing_wins Hall of Fame

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    ok, imo, if that's your attitude, then the trend will continue.

    i have to admit, i m not an expert in this area by any means.

    the stats show TP is one pagerank below FYB. FYB has 10 times the backlinks on yahoo, msn and other search engines.

    i also know, u have a arrrangement with the TPA which adds to your membership.
     
    Last edited: Mar 26, 2011

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