The Forehand: Busting misconceptions once and for all

Discussion in 'Tennis Tips/Instruction' started by 10isfreak, Jan 11, 2013.

  1. 5263

    5263 G.O.A.T.

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    the things a club, lol. Will dominate all but the best of the best unless you can't
    swing it. I have 2 in my collection that we play with sometimes. My son even
    won a few Jr tournys with them.
     
  2. sureshs

    sureshs Bionic Poster

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    As was extensively discussed in the Rackets section, it appears that an inversion exists in the rec world. For pros, a PS 85 will not cut it today. For rec players, it probably will not make even a 0.5 difference in level one direction or the other. "It" refers to pro rackets in general. I have used it so far because it is the only frame I like. But sometimes the mini Nadals get me thinking.
     
  3. Cheetah

    Cheetah Hall of Fame

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    i've hit with them before. something about the feel i don't like. the throat always felt stiff. i like to polarize my sticks so that you can feel some bend in the throat when you swing.
     
  4. sureshs

    sureshs Bionic Poster

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    That is Breakpoint's domain of expertise. Its head light nature makes it much easier to swing than lighter rackets. It absorbs all the shock, and with my Shockshield grip instead of the original leather, and the Shockshield strings, it is as if it is not there. Quite the opposite of a club. I am the racket and the racket is me.
     
  5. 5263

    5263 G.O.A.T.

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    Honestly it might affect how you feel about using more modern approach.
    While I do believe you can use modern with the smaller heads, it does take
    a bit more skill imo.
     
  6. 5263

    5263 G.O.A.T.

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    More likely we just mean different things by the term club, but who knows with
    all that anti shock gear you are sporting. I don't even use a rubberband dampner
    and full poly because I want to feel it when I get it wrong.
     
  7. sureshs

    sureshs Bionic Poster

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    I liked the "naked" feel of leather as well, but got scared when seeing the number of injuries among club players. I have managed to stay injury free and have deliberately gone for a muted feel to prolong my playing life. Sometimes I wonder about that too.
     
  8. 5263

    5263 G.O.A.T.

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    I'm convinced if the strokes are right with clean contact, there should be little
    problem.
    Easy for me to say...since it's working for me right, lol
    If I was hurting I might think different.
     
  9. sureshs

    sureshs Bionic Poster

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    Guys, check out this reference from another thread: feeltennis.net

    Some great gems there.

    Separates out rotation and extension of the arm int he forehand

    Emphasizes the movement of the arm through the contact zone towards the target

    Explains how the natural upward motion of the forearm for topspin leads to the inward turn towards the body (no deliberate yanking or pull back)

    Has excerpts from Nadal's autobiography where he explains that every shot is a little different and minute adjustments need to made (correct technique is a myth).


    Very very good points and completely in line with my practical experience.
     
  10. NLBwell

    NLBwell Legend

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    Everyone wants to be so exact and pretend that they can decide to hit the ball 1/2 inch lower in the stringbed or hit with an 8 degree angle or a 10 degree angle. I feel lucky to just get my racket on the ball quite often.
    Federer and Nadal didn't learn by trying to hit the ball in the lower part of the stringbed, or worry if their racket was at 10 or 15 degrees at impact. They just hit the ball over and over again and their body learned the best way to hit the ball.


    (I do find the videos intensely interesting, but from an academic point of view.)
     
  11. sureshs

    sureshs Bionic Poster

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    But since we don't hit so many balls, a little tip here and there from others helps a lot.

    For example, I have discovered the key to the perfect serve, but more on that later.
     
  12. 10isfreak

    10isfreak Semi-Pro

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    The point of the accuracy here is not to try and replicate the movement in all its exactness... I never implied this anywhere. The point of this precision is build knowledge.

    A thing that people rarely get is that knowledge is power. Knowing how each element of a system interact with great precision yields you the control over this system: for every effect you deem desirable, you can devise a way to make it happen. If you do not have that knowledge, you are indeed, as you say, lucky to make it happen.

    Federer, Nadal and some other pros might have just been lucky. Their tendency to hit in some places of their stringbed, to close more or less their face and adjust their swing path might all be the fortunate response that have been built as an adaptation to several experiences they had on the court. It migth just be a coincidence -- and it probably is, for a lot, a coincidence.

    Regardless, knowing what they do so well and why they're so good does make a concrete difference. It first allows you to dismiss certain beliefs about tennis... You can waste your time and efforts, or you can learn how to make your life easier with proper technique.
     
  13. 10isfreak

    10isfreak Semi-Pro

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    This time, science does confirm people's intuition: getting the ball low does limit their ability to do as they like. By kicking it too high, you're playing in their home field... it's not a good idea.
     
  14. 10isfreak

    10isfreak Semi-Pro

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    The dwelling time is ridiculously small, as you probably know. Furthermore, the effect of brake is a function of time -- it does not slow down as a result of friction, but as a result of friction over time.

    When a ball travels in the air, its spin and pace both reduce as a result of friction, but it reduces over travel time, not instantaneously. It's the same for the string bed as for air, except that the ball stays for something like 0,005 seconds in the string bed.

    It's likely that if you do get the numbers down, the effect of this is limited.
     
  15. toly

    toly Hall of Fame

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    Yes, nothing can happen instantaneously. But, let’s assume that incoming ball has 2000rpm topspin and Nadal hits TS FH with 5000rpm. Is it possible? Yes, he did it many times.

    So, during dwell time he eliminates incoming ball 2000rpm spin and creates his own opposite 5000rpm topspin. This transformation is done mostly by using friction between strings and ball.

    Thus, 0.002-0.005sec is more than enough to just stop ball’s rotation.:)
     
    Last edited: Jan 14, 2013
  16. sureshs

    sureshs Bionic Poster

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    Everything happens in that time.
     
  17. 5263

    5263 G.O.A.T.

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    Exactly right.
     
  18. 5263

    5263 G.O.A.T.

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    full of good info here!
     
  19. dominikk1985

    dominikk1985 Legend

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    Do you think that those guys intentionally hit the ball below the center?
     
  20. luvforty

    luvforty Banned

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    i call it subconscious intentional.

    same reason people hit high (closer to the tip), while the real sweet spot is right in the middle of the string bed.

    you hit thousands of balls, trial and error, the brain knows where it's sweet where it's bitter.
     
  21. sureshs

    sureshs Bionic Poster

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    And sometimes it may not be desired - i.e. it may be a mishit which we think had a purpose which it did not have
     
  22. corners

    corners Legend

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    You're correct that the closed racquet faces we see on the forehand in the pro game are primarily a response to counter balls on the rise. But closing the racquet face is also effective, and sometimes a requirement, to counter incoming balls with heavy topspin. If you hit a ball with heavy topspin at a wall the ball will bounce "up" off the wall. The same thing happens when a heavy topspinning ball bounces off a stringbed. Closing the racquet face also lowers the bounce trajectory when returning heavily spun balls.

    Closing the racquet face unquestionably increases topspin, and will produce topspin even with a completely horizontal swingpath.

    You can illustrate this using TW University's shot simulator.
     
  23. LeeD

    LeeD Bionic Poster

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    What is "correct"?
    EvonneGoolagong often hit forehand with an open face.
    DavidFerrer seldom.
     
  24. corners

    corners Legend

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    John Yandell did a study of video of Fed, Nadal and Djoker and found that all three players hit 1-2 inches outside the center of the strings far more often than they hit the center of the strings. They tended to miss the center toward the tip of the racquet most often. There was nothing in his data to suggest that they strike below center more often than anywhere else.
     
  25. Chas Tennis

    Chas Tennis Hall of Fame

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  26. corners

    corners Legend

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    This was the finding of the TW Professor in this study: http://twu.tennis-warehouse.com/learning_center/location.php

    Balls that impact either above or below center will rebound about 9 miles per hour slower than one that impacts dead-center, and the above study found that balls impacting below center (toward the ground) will bounce off with about 35% more spin than those hitting dead-center and about 60% more spin than those hitting above center (toward the sky). So missing the sweetspot has pretty big implications for shot speed, spin and accuracy.
     
  27. sureshs

    sureshs Bionic Poster

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    Remember that the ball also slides along the strings during the dwell time, especially with the low tensions of the pros, so there may not be just a single area of contact.
     
  28. tennisfan69

    tennisfan69 New User

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    Suresh, do pros use low tension? any idea for tension ranges? thanks for the info.
     
  29. sureshs

    sureshs Bionic Poster

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    I am reading that pros are doing 40s these days. This is what the latest issue of RSI mag says. Of course, they restring every day so that is their real tension (max loss is within 24 hours). On the other hand, I think Nadal was still in the 50s.

    I would suggest you post in the rackets or strings section and see if drakulie answers. He is a pro stringer.
     
  30. Off The Wall

    Off The Wall Semi-Pro

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    This is not by accident. Advanced players prefer to hit there.
     
  31. luvforty

    luvforty Banned

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    yeah, certainly doesn't need a 'study' for this..... it's pretty straight forward 7th grade physics stuff
     
  32. 10isfreak

    10isfreak Semi-Pro

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    The contact lasts less than a fifth of a blink of an eye... that is, about 0,004 or 0,005 seconds. The ball doesn't even slide a millimeter, let alone spinning due to sliding.
     
  33. luvforty

    luvforty Banned

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    huh? what makes that hissing sound when you hit a spin serve, or when you cut a heavy slice? (if you have experienced either)
     
  34. 10isfreak

    10isfreak Semi-Pro

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    Actually, your inference is not justified. One, the racket is not standing on a table... it is moving -- there is kinetic energy transferred from the racket, to the ball. Nothing whatsoever implies that friction alone is responsible for spin variation, much rather, you have TONS of directed energy to negate the effects of spin.

    Also, spin reduces through the air and at ground contact... which are both a lot longer and a lot more annoying to me that barely touching strings which aren't nearly as sticky as a tennis court.
     
  35. 10isfreak

    10isfreak Semi-Pro

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    My psychology teacher resumed the value of science in a few words. He said that psychology, as any scientific field, empowers its user with regard to some object of study. In that case, it grants the user power over himself and others.

    In science, we do not happen to find stuff out of sheer luck... we devise systematic experiments to try and avoid the inefficiency of trials and errors. Knowing what to do because of science is being smart; knowing what to do out of personal experience is sheer luck.

    Experience drives you depending on various factors which you do not control... they may drive you to do exactly what is required in one situation or even many situations, but it all depends on how coherent the sample that constitute your experience is with reality as a whole. (Your life is effectively a sample of a population which regroups the experience of everyone, as well as experiences that could have occurred, but didn't)

    If your experience fits the bill, you do not succeed out of genius or because you are smart... you simply were lucky, like the guy who earned his fortune with a lottery ticket.


    The only way to be intentionally succeeding is to build knowledge and use it. It's also one of the very few things that should separate adults from children who do not have the biological luxury of being capable of formal reasoning, which includes the deductive reasoning which is required to find concrete applications to abstract ideas such as scientific theories.
     
  36. bad_call

    bad_call Legend

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    well posted sir...applaud your patience as it exceeds mine. :)
     
  37. sureshs

    sureshs Bionic Poster

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    It has been filmed to slide several inches along the strings, dragging the strings with it, and then the strings snapping back into the ball to produce spin.

    Blink of an eye, millisecond, etc does not convey what is happening as it is beyond human intuition. A millisecond is a huge amount of time.
     
  38. Povl Carstensen

    Povl Carstensen Legend

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    I do not think the strings move several inches. More like, half an inch?
     
  39. Povl Carstensen

    Povl Carstensen Legend

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    Is the purpose of the science of psycology to get power over yourself and others?

    Experience is sheer luck? Not at all. Science is great, but experience is great teacher especially when feeding of imagination and intuition (neither being "luck"). Certainly it would be a dull and bland world with all science and no experience and fantasy and so on. But, a perhaps an easier world to have power over.
     
  40. Geology_Rocks!

    Geology_Rocks! Semi-Pro

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    I wanna see this film.
     
  41. TW Staff

    TW Staff Administrator

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    Thread restored. Please do not link to promote outside sites as those posts will be deleted. Links in themselves are not the issue. Links that are deemed as promotion/advertising to any site, whether that site is or for profit or not, will be removed.

    Thank you,
    Talk Tennis Admin.
     
    Last edited: Jan 17, 2013
  42. corners

    corners Legend

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    Well, if that is so then Djokovic, Nadal and Federer do a poor job of it. They don't hit there anymore often than anywhere else, at least according to Yandell's analysis.
     
  43. sureshs

    sureshs Bionic Poster

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    It was interesting. The counter argument to it at that time was he should have counted only those pics in which it was absolutely clear that topspin was being hit.
     
  44. corners

    corners Legend

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    Yes, but the TW Professor's study on impact location and spin showed that balls that impacted above center had less spin, and those that impacted below center had more spin. The sliding of the ball is part of the reason why this happens, but he was able to aim precisely 2 inches above and below center. So if you want to get more spin you need to have the ball impact below center (and then hope it doesn't clip the frame). If it hits in the center and then slides down you'll not get more spin.
     
  45. Wegner

    Wegner Rookie

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    Suresh, in a study we did at MIT in Boston, with the intention to hit plenty of topspin and quite hard, the ball moved about a quarter inch across the strings. This was filmed at 1,000 frames per second. The ball was in contact with the strings for about 5 frames, which would make it around 5 thousands of a second.

    The racquet tested was strung at about 50 lbs on the main and 52 on the cross (usually stringers tensions are the other way around, more tension on the main and less on the cross. Our racquet experiment was done to equalize the tension without deforming the racquet, as when you install the cross strings the main ones get deformed, causing them to acquire more tension).

    The stroke in the test was a down the line one-handedd backhand with an up and across stroke similar to Federer's (diagonal combination of effort, using a kinetic chain with a strong emphasis on puling the shoulder blades together). Due to the computer/camera/lighting position combination, this was the best take where we could measure clearly the parameters.

    And as for feel, you definitely feel the impact, and if you are in the Zone, this perception seems prolonged.

    When I told Vic Braden the results of these findings, he seemed quite surprised that the ball slid that much on the strings and that the impact was so long, and he expressed interest in seeing the film, which at the time was posted on the Internet by MIT. Braden's take was closer to one millisecond.
     
    Last edited: Jan 17, 2013
  46. sureshs

    sureshs Bionic Poster

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    So how do you reconcile these different results? I think I saw a paper by Rod Cross stating 3.5 cm, then Wilson is showing a much bigger displacement of the strings in their lab, some people claim several inches.

    The 5 ms is very consistent with Rod Cross's findings.

    I string at 60 and have never experienced this sliding of the ball on the strings, but I assumed it was because the pros are stringing much lower these days.

    I will fire off a question to TWU prof right away. 1/4 inch vs several cm does not make sense at all.
     
  47. Wegner

    Wegner Rookie

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    Thank you, corners. Wow, finally someone corroborating my theories and teachings I have applied for decades. It is even in my ESPN International tips of 97/98/99. Hit below the center for topspin, above the center for slice!
     
  48. Wegner

    Wegner Rookie

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    Suresh, racquet tension and power applied are factors that affect the ball-string contact length. For a lower tension and less power your figures may well apply. Or perhaps the biggest variant is the direction of your force. For example, a player like Ferrer, who is attempting a lot of topspin, may have a longer ball-string contact than a Federer stroke. The figures I gave you were also a one-handed topspin backhand, where in general there is more extension than in the forehand, where (my contention at least) you pull from the racquet at impact rather than extend.

    So with that in mind we are both, you and I (and these studies you mention) right within reasonable parameters.
     
  49. sureshs

    sureshs Bionic Poster

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    One thing I know is that faster the shot, less the dwell time. I think the dwell time varies from 1 to 5 ms, from what I have read.

    While waiting for TWU prof to answer, I looked up some of his articles. I think what you and another poster are saying here is correct - probably the string movement and ball sliding is only a quarter of an inch, not the bigger numbers claimed elsewhere.
     
  50. bhupaes

    bhupaes Professional

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    Well, the difference in the sound of the impact between heavily spun shots and flat shots is a good clue. The scratchy/rasping sound of a kick serve is surely due to the ball sliding on the strings more than for a flat serve. Same is true for ground strokes. A lot can happen in 5ms... !!
     

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