Knee Bend?

Discussion in 'Tennis Tips/Instruction' started by Lotto, Dec 30, 2008.

  1. Lotto

    Lotto Professional

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    How important is the knee bend in pro groundstrokes and how does it contribute to power? It's just that I was watching some Federer practice videos on youtube and it looks like he barely bends his knees at all.
     
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  2. SystemicAnomaly

    SystemicAnomaly G.O.A.T.

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    Knee bend should help you to produce power more efficiently -- it should greatly assist in an effective kinetic chain. You can certainly produce power w/o using much of your lower body, but if you do this a lot it would tend to fatigue your arm/shoulder. Use your legs and hips to start the kinetic chain and save your arm for controlling the racket (& for transferring the body power to the racket). I would advocate bending the knees for most shots -- low, medium and high ones.
     
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  3. mike53

    mike53 Professional

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    #3
  4. fuzz nation

    fuzz nation Legend

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    If your knees are straight, those big muscles in your legs are effectively isolated and can't contribute any energy to your swing and if a ball is down low, you have to bend those knees or else your mechanics (and control) will go right out the window. While you may see a player's knees straightened out upon contact with a groundstroke, it's likely that they were flexed beforehand to drive upward and forward to initialize the swing. For good strokes, there a lot more energy potential in the legs than in the arms. This is especially true for serving!
     
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  5. Lotto

    Lotto Professional

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    Yeah but in this one it doesn't look like he is:

    http://www.youtube.com/watch?v=Fr7Slgi47YA


    I know what you guys are saying and I agree completely. It's just looking at some pros practicing it doesn't look like they use the knee bend at all yet are still generating huge amounts of power.
     
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  6. mike53

    mike53 Professional

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    Yes, I see. Maybe there is more bend in the video than meets the eye. Maybe the practice strokes are not as powerful as those in matches. Definitely a different form in practice than in match play.
     
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  7. fuzz nation

    fuzz nation Legend

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    Yeah, these guys are so flippin' good that they can get away with some lazy stuff when they're having a knockaround. I've you ever get to have a casual game of catch with a baseball player who knows good mechanics, they can just about break your catching hand with what looks like a casual flick. It's just not fair, I tell you!!!
     
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  8. Lotto

    Lotto Professional

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    Well, I don't know anything about baseball because I'm irish.

    So, why can they do it, is it technique like or what?
     
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  9. certifiedjatt

    certifiedjatt Banned

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    the exaggerated knee bend is overrated.
    you will naturally slightly bend your knees when you're hitting a ball. if the ball is really low, you will naturally bend them more to get to the ball.

    just keep it natural.
     
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  10. tennisfreak15347

    tennisfreak15347 Banned

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    well in that video, they're just warming up for a match. Also, the knee bend is still visible...
     
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  11. Charlzz

    Charlzz Rookie

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    Yeah, but Federer is still not hitting anywhere as hard as he does in real matches, which is where the little bit extra from the knee bend helps. In practice, he probably doesn't want to stress his knee unnecessarily. Part of the power is good technique, fast enough racquet head speed, good body rotation.

    Try the following. Just hit about 70% pace, nice and relaxed, not trying to hit all out. That's probably still reasonably powerful, especially if a complete beginner sees you. Federer is in the top echelons of the game, so it would make sense a pretty casual hit from him is still quite powerful.
     
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  12. GeorgeLucas

    GeorgeLucas Banned

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    hohoho

    Yea... TW posters really exagerate the amount of knee bend necessarity to hit a forehand or backhand - if your knees were 3 inches above the ground you'd still get posts saying "Bend more!! Get down for the shot!!"

    Hell, those shots that Federer hit with his knees nearly straight are probably harder struck than 80% of yours. From purely a physical standpoint, kneebend doesn't contribute much in of itself. Here comes something revolutionary: If you want a heavier stroke, you ought to focus more on your upper body (i.e the torso, shoulder, arm in harmony) than what is below the waist.
     
    Last edited: Dec 30, 2008
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  13. Lotto

    Lotto Professional

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    I see. Some interesting posts.

    Should I listen to my coach then?

    He really emphasises the knee bend and he has me nearly sitting on the ground!! I noticed though, when I was practicing today that when I bend my knees a good bit(I normally don't bend them that much at all) that I get a hell of a lot of "free" power and my accuracy and control improve so much. I could paint the lines and corners with my down the line one hander. It was mad!
     
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  14. SystemicAnomaly

    SystemicAnomaly G.O.A.T.

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    Yeah, listen to your coach. It is a good habit to develop. It would be relatively very easy for a player who is in the habit of bending the knees, not to bend them on occasion where it might not be critical. On the other hand, players who have not developed the habit of bending the knees, will almost never do it -- this can be a problem.

    Note that the legs muscles are much stronger than your shoulder & arm muscles (more than 2x). Bending the knees really helps you to generate power more efficiently as I said before.
     
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  15. ericwong

    ericwong Rookie

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    IMHO, knee bend also stabilise your upper body. Hence, it allows you to do a good unit turn before striking the ball. of course, you straightened it if you consciously 'jump' into the ball to give that extra punch. The last bit is so-called ,the leg-drive.
     
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  16. herosol

    herosol Professional

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    exactly! it's really about the efficiency.
    the use of a well-created knee bend is what creates athleticism. Athleticism is what separates the normal athlete from the professional one, because thee extra athleticism in my mind gives ultimate efficiency in all categories.

    All things said, remember one thing, in tennis, the hands are the MOST IMPORTANT factor to any shot.
     
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  17. certifiedjatt

    certifiedjatt Banned

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    i love how people throw around words like "efficiency" without drawing a direct link between the knee bend and a more power stroke. so what if the leg muscles are 2x strong as the shoulders and arms?

    i would love someone to demonstrate, using FACTS instead of "logic" and "common sense", the effects of a knee bend on how powerful a stroke is.
     
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  18. jasoncho92

    jasoncho92 Professional

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    I agree that its exaggerated on these forums, but bending your knees in tennis is anything but natural (for most people).
     
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  19. kelz

    kelz Professional

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    Leg drive is very important. All power comes from the ground (your legs in this case acts as a medium in which power is transferred through to your hitting racquet) and thus it is the fundamentals to racquet head speed and thus power. Federer is an exception because he's a freak.
     
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  20. BeHappy

    BeHappy Hall of Fame

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    from biomechanist Bruce Elliot, extract from tennisplayer.net

    Why do you need a good leg drive? I'll give you three reasons.

    If you have a leg drive and you drive up with my legs, it drives your shoulder up, and that drives your racquet down


    edit, I thought you were talking about knee bend as it pertains to the serve, BB will come in here in a minute and kick everybody's ass over this lol
     
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  21. phoenicks

    phoenicks Professional

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    you guys, bending knees can really help adding juice to your shot, listen to what james blake, who hits a big forehand have to say,

    http://au.youtube.com/watch?v=kluhYnSlGZU

    pay attention to it after 0:15.
     
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  22. phoenicks

    phoenicks Professional

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    the reason why pro's generate so much power even when they are not bending knees, as shown during some warm-up, is because their core strength, trunk rotation, and various other upper body muscle are develop to a very high level, thus they can get away with some knee bend while hitting a lot of power. Furthermore, their clean contact, racquet head speed, and
    timing is honed to such marvelous level that they can hit a shot much powerful than 99% of us when we go for the broke.
     
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  23. Bungalo Bill

    Bungalo Bill G.O.A.T.

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    What SystemicAnomaly said.

    Fluidity in the legs helps your body move better. It helps it coil and uncoil well. This all contributes to racquet acceleration.
     
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  24. GeorgeLucas

    GeorgeLucas Banned

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    stupid

    This is very telling. You heard it here yourself, folks - by focusing solely on harmonizing and solidifying the upper body's functions in a stroke, you can hit 99% harder!!

    I never understood why in the world we need to explode off our legs so much. Looky here: maybe by exploding upward, we can add about 5 or so mph in the postive y direction. That is not so much.

    The role of legs in the stroke is often misconstrued as a base of power, something that connects your body to the hidden energy stored in the tennis court itself which magically grants you extra racquet head speed. This is not so. The legs are simply there so you can bring your TORSO (the "mitochondria" of the forehand organism) into a space where it can do it's job most effectively.

    Who cares that legs are 2x as strong as arms. Are tugboats faster than speedboats? No. Can they lug more weight? Yes.
     
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  25. certifiedjatt

    certifiedjatt Banned

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    this is the perfect post.
     
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  26. certifiedjatt

    certifiedjatt Banned

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    another perfect post.
     
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  27. Djokovicfan4life

    Djokovicfan4life Legend

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    Bear in mind that this is the same guy who describes good footwork as "running to the ball".
     
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  28. Bungalo Bill

    Bungalo Bill G.O.A.T.

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    I think he is finally done licking his wounds after I destroyed his reasoning on footwork and coordination. Looks like he is ready for another beat down.

    However, I just ignore him, but you were funny to bring up "JUST RUN TO THE BALL." Yeah, that explains a lot!

    Unfortunately, he was right about the exaggerated knee bend. People do sometimes use their knees improperly. The knee bend for the serve is a byproduct of how your body shapes through the serve motion to support your balance and thrust to the ball. So, I will have to wait for another one of his rants about nonsense tennis. Keep in mind, he seems like a frustrated 3.0 player. JUST RUN TO THE BALL!

    What is hilarious is he is looking for perfect descriptions from others when he himself rarely explains himself. Such as "just do things naturally." What the heck does that mean? LOL! What is natural to one person may not be natural to another. What is natural to another may be detrimental to their serve motion.

    Of course, he is scared to be the first to explain things, because once he does, we are all over it.

    Let the poor little child stay in the background and have his little fun.
     
    Last edited: Dec 31, 2008
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  29. certifiedjatt

    certifiedjatt Banned

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    i pity you. you know why? because you're and old underachiever. you want to be a mentor, but no one really cares about your opinion. you want to believe that your words are valuable, but you rarely get confirmation from people who know what they're talking about. so, you rely on ambitious, excited, thirsty-for-knowledge, but perhaps not critical, teenagers on a tennis forum to offer you the recognition you lack in your personal and professional life. you believe that your knowledge of tennis is incontrovertible and comprehensive, but you have yet to read literature on tennis written by someone other than a coach or a player.

    so, you come on an internet forum to have people massage your ego.

    destroyed my reasoning on footwork??? i would LOVE to see THAT post.

    and i probably am a 3.0 player--if a 3.0 can consistently beat division 1 college singles players, than i am happy with that. i don't "kneed" a freakin' number attached to my skill level. i play for fun.


    i just hope that by the time i get to your age, i have more to offer to the world than unscientific, unproven, untested advice to anonymous people on the bloody internet.


    i AM looking for the perfect explanation from people. you know why, you internet alpha wannabe? because i don't know it. i don't KNOW the perfect explanation for tennis strokes, tennis mechanics and "footwork." that's why i QUESTION what has been passed on from generation to generation. i have more questions than answers. you seem to have an idiotic, arm-chair answer for everything. THAT is why you are a sucker.
     
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  30. baseline08thrasher

    baseline08thrasher Semi-Pro

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    ONE OF THE MOST IMPORTANT THINGS TO REMEMBER AND THINK OF WHILE PLAYING TENNIS!

    if you aren't bending your knees well, then there is no energy.

    When your not bending your knees well, you're not playing good tennis.

    The truth. ^
     
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  31. LeeD

    LeeD Bionic Poster

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    "well" is subject to interpretation.
    I've seen 6.0 players who don't can't bend their knees on each shot. They can beat you and me 1 and 1.
    You bend if you got the energy and will.
    You learn to conserve energy to make it thru the day, and bending excesively only wastes energy.
    You need your thighs to get to the ball.
    Just how hard do you need to hit anyway??
    Remember, a consistent softly hit deep ball always beats a hard hit short ball.
    Yes, a hard hit deep ball, consistent, will win in the end.
    We don't consistently hit hard and deep, just a reality.
    But we can hit soft and deep MOST of the time, more often than hard and deep.
    So why all the emphasis on knee bend?
    Golfers hit 300 hards with barely bent knees.
    Baseball players bend more, but they're really trying to shrink the strikezone.
    Hockey strikers bend a bit, but not much.
     
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  32. mental midget

    mental midget Professional

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    all righty then-

    it's hard to shift your weight and retain your balance without some degree of knee bend, so if you're in the camp that regard weight shift and balance as good things in a tennis stroke, then, there you go. it's a means to an end, i'd leave the aesthetics and degree of it to the individual based on trial, and error, and refinement.

    the key is understanding the principle, not the procedure. the average recreational player has neither the time nor the capacity to retain thousands of coaching aphorisms with regards to stroke mechanics, strategy, footwork, timing, etc.

    i see way too many frustrated club players stomping around the court, muttering wrote procedural advice, caught in an analytical vortex that sucks away what little intuitive athleticism they may have begun their journey with.

    overanalysis . . . the last refuge of the bad athlete.
     
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  33. LeeD

    LeeD Bionic Poster

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    Absolutely right !!
    If you can hit your groundies as hard as the best player you have seen, it's fast enough.
    Now I didn't say your groundies as fast as the fastest groundies you've seen, I said as fast as the BEST player you have seen, and kinda wanna emulate.
    You know the difference.
    Anything hit at 6.0 speed is fast enough.
    And 6.0 speed can vary from 60-90 mph groundies.
    And serves, just add 40-50 mph.
     
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  34. certifiedjatt

    certifiedjatt Banned

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    #34
  35. phoenicks

    phoenicks Professional

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    just want to clarify things to prevent further misunderstanding, I am not telling you to just focus olely on upper body for the groundstrokes, bending knees are absolutely very very important for us, pros may not bend knees during warm up, but during the match they sure as hell bend their knees !!!
     
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  36. Bungalo Bill

    Bungalo Bill G.O.A.T.

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    "I have seen WAY TO MANY club players stomping...? The key is to understanding the principle, not the procedure?" Well, thank goodness you arent a Doctor! LOL, I have been around tennis way too long to know this is a bunch of BS.

    I see a lot of club players that lack knowledge in their strokes and are dying for good instruction to help improve their games. I dont see anyone muttering except those that just want to complain like you.

    And providing a bad and inaccurate analysis like you have is even worse. It dooms people to failure and complacency like where you are.
     
    Last edited: Dec 31, 2008
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  37. certifiedjatt

    certifiedjatt Banned

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    i'm not going to let you get away with passing on BS. every BS, self-aggrandizing post you type that i happen to see, i will come after you like a rottweiler.

    you have been around tennis for too long. which is why you are immune to new developments, i.e., OBSERVATIONS that intelligent people have made. some of these observations dispel the nonsense that you and others have grown up with, and are foolishly perpetuating.

    and by the way, saying "i have been around tennis for too long" is the first sign of complacency. you, sir, are an epic failure.
     
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  38. certifiedjatt

    certifiedjatt Banned

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    wicked good post. especially the "analytical vortex" part. that's gold jerry, gold.
     
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  39. jessey

    jessey Rookie

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    I don't know whether it adds power or not, but during groundstrokes, I've found the most important thing for me to keep in mind is the contact point--mantaining a constant and comfortable contact point. So I bend my knees lower when the ball is lower, keep them higher if the ball is higher.

    I've found the most important thing for my is to keep a stabilized upper body, and with stability comes controlled power.
     
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  40. mental midget

    mental midget Professional

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    i'm with you there, stability is the name of the game. obviously, there's a fair amount of lunging and leaping inherent to the game, but staying as balanced as often as possible is . . . a good idea. if you're looking for a simple guiding principle, that's not a bad one.

    i think what made edberg just look so good out there was the guy never seemed off-balance, like, if at any moment during a point, you were to freeze him, make a mold, and cast a statue from it, your result, no matter how contorted, would be positively Calder-like in its balance, and its elegance.

    . . . aaaand there's my vaguely homoerotic edberg reference for the day.
     
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  41. Djokovicfan4life

    Djokovicfan4life Legend

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    Yeah, I had the "pleasure" of seeing myself on video for the first time and I noticed that I exaggerate the knee bend on the serve quite a bit. I think part of the problem is my wide stance. My back leg bends almost to where the lower part of it is almost parallel to the court! By the time I begin my forward swing most of the knee bend is gone and I've lost most of the extra power that I could be generating anyway. So the degree of bend and the timing of it are both way off. Not good.

    Strangely, this doesn't seem to be a problem for guys like Sampras and McEnroe, who both used very wide stances.

    P.S. Happy New Year, Bill.
     
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  42. Bungalo Bill

    Bungalo Bill G.O.A.T.

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    Yes, this is not good, however, you found something that is really important to know. You said "the degree and TIMING of it are both way off."

    This is huge. I have had some time to get back on the courts and noticed I need to get some serve practice in because my "knee bend" and my upward thrust timing is off which means my serve was not performing well.

    The legs are huge in a serve.

    Happy New Year to you too.
     
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  43. Ballinbob

    Ballinbob Hall of Fame

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    Quoted from the How to play super tie-breakers thread:

    "the second guy was known as a pusher around the courts. but it wasn't his "pushing" that caused the problem for me (i lost)." and then: "i went into the match playing my game, serve and volley" and then: "i got tight. started throwing in double faults. crappy serves. and this wasn't because he was a pusher, but because i was now afraid of losing because everyone expected me to beat him easily"

    VVVVVVV

    So what we have here is a S&V player with no mental toughness and looses to pushers but can still beat DI players consistently. You guys should know by now how big of a problem pushers are at the DI college level and how big of an advantage pushers have over a S&V PLAYER.

    I say we just drop everything and let the guy go. He obviously is way smarter than the rest of us, so just let him go to his Division I college pushers for advice.
     
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  44. LeeD

    LeeD Bionic Poster

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    I know this might sound really stupid...
    In my day, I could usually beat up to Div1 low level singles players, as a 4.5 Mens. That's B ranked, but regularly entered Open events.
    But I'd regularly hit with TomBrown, a pusher of 62 then. He, I surmised, could beat me pretty much 2 and 2.
    All "pushers" are not the same.
    All Div1's are not the same.
    Some people play great against big hitters who move the ball and play top level tennis. Then they get stagnant against slower hitters...they lose interest, they can't concentrate.
     
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