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#21 |
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Hall Of Fame
Join Date: Mar 2011
Location: San Diego
Posts: 2,243
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No. This is fact.
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Yonex VCore 100s - SW 351 6pts HL Tour Bite / N.VY 16 @ 51lbs |
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#22 |
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Hall Of Fame
Join Date: Apr 2010
Posts: 2,401
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#23 | |
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Talk Tennis Guru
Join Date: Oct 2005
Posts: 25,889
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Quote:
2. I think the path to the ball has to always be from the lower half, and as you say the eventual contact may be slightly different. |
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#24 |
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Hall Of Fame
Join Date: Mar 2011
Location: San Diego
Posts: 2,243
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...........
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Yonex VCore 100s - SW 351 6pts HL Tour Bite / N.VY 16 @ 51lbs |
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#25 | |
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Rookie
Join Date: Dec 2012
Posts: 206
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Quote:
Here's Federer and Nadal. Yellow marks the face before contact, green is at contact and Red is after contact. ![]() ![]() That's WAY more horizontal than what people on this blog think it is. "At impact for the forehands shown here, Federer’s racket face is tilted forward 11 degrees at impact and Nadal’s racket face is tilted forward 15 degrees (relative to a perfectly vertical racket face). And the racket path used by each player for the same forehand as shown above is interestingly the same: the racket for both Federer and Nadal are moving 18 degrees upward…" 18 degrees... do you realize how flat this is? And they're not hitting winners, they're rallying with their practice partner! The host did what none of you did and what people like Oscar will never do: he studied it with thousands of pictures taken from super-high speed videos. Do you know how he compares these two forehands? If I recall, he numbers about 40 anatomical movements that both of these players share -- and some which aren't shared by most top pros. Why does Nadal hits loopy shots and Federer hits mostly flat strokes? "Nadal often swings on a much steeper upward path than Federer (especially on the clay) and this steeper path further amplifies the amount of topspin he generates by tilting his racquet face forward throughout his forward swing. Nadal’s steeper overall swing path (see below), combined with his extreme forward racquet tilt throughout his forward swing through impact, results in 25% higher topspin production, on average, compared to Federer, as well as a slightly higher launch angle off of the stringbed that creates a shot with a slightly higher trajectory." ![]() Nadal's forehand is indeed swung at nearly 30 degrees here... If you understood what I have been saying, you know what happened: loads of spin, but also a very high ball. Last edited by TW Staff : 01-17-2013 at 12:53 PM. |
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#26 |
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Rookie
Join Date: Dec 2012
Posts: 206
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#27 |
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Legend
Join Date: Mar 2008
Posts: 7,371
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I would expect they are, but can't say from those pics...not that I can tell.
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************ MTM Instructor -Pro Supex Big Ace |
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#28 | |
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Talk Tennis Guru
Join Date: Oct 2005
Posts: 25,889
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Quote:
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#29 | |
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Hall Of Fame
Join Date: Feb 2011
Posts: 2,808
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Quote:
not the hand tilts the racket forward, the ball does. that is the only possible explantion for the racket staying at the same tilt angle for so long and then sudddenly turn over. or is anyone suggesting the hand does this drastic move just in the moment of contact? |
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| dominikk1985 |
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#30 |
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Talk Tennis Guru
Join Date: Oct 2005
Posts: 25,889
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Very very interesting. Is there a pronounced going over the ball at contact in the dwell time, or is it just recoil?
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#31 | |
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Hall Of Fame
Join Date: Aug 2006
Posts: 4,981
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Quote:
dude - u made my day. i'm ready for a beer.
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check the facts before believing what you read and hear...or accept blame for not doing so. |
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#32 | |
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Professional
Join Date: Feb 2011
Location: Baltimore, MD
Posts: 1,318
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Quote:
1) I believe that most racket face reorientations after the ball impact - the red shown in the excellent Tennisspeed illustrations above - could be closely correlated with how far off the racket centerline the ball impact is located. That is, mostly the impact torque during impact turns the racket. I've looked at this issue in a few high speed videos but not enough to be sure. For pros, I believe that if the ball hits on the area of the strings in the bottom half of the racket face the top edge of the racket tends to go forward (closes). And if the ball hits on the strings in the top half of the racket face the top edge of the racket goes backward (opens). The pros more consistently hit in the same part of the string face. On most videos of my strokes, hits are more random above and below the centerline. The racket turns up if above or down if below the racket centerline. What the racket face is doing can easily be seen in high speed videos. Where were the ball hits on the Tennisspeed illustrations? 2) I have read more than once that the impact time between the ball and racket strings is very short (was it 0.005 sec? or 5 milliseconds?) and the racket effectively does not change orientation during the time that it is in contact with the ball. What is the research for that view? How fast does it change orientation and what is the effect of the elastic strings on the forces given to the ball. 3) While the pros hit slightly top edge forward (closed), is the racket tending to open or close a little more just before impact? In other words what are the hand forces/torques doing at impact. 4) Does both hitting on the bottom half of the racket face and using a slightly closed racket face make for better control as well as add topspin. Does the racket close slightly to cover the ball a little in the few milliseconds during impact? Also, if the strings are closed the top half of the ball is always impacted and vice versa. Last edited by Chas Tennis : 01-11-2013 at 03:00 PM. |
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#33 | |
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Hall Of Fame
Join Date: Feb 2011
Posts: 2,808
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Quote:
when you push against an object at a point away from the center of mass it will rotate. and since the ball has inertia that rests against a change of direction the upward moving racket face will brush up the ball causing the ball being below center at some point. this causes the racket to twist and "go over the ball". the ball creates a hinge for the racketface to rotate around. the tennisspeed guy himself proves that the racket is not turned by the hand. at about 3:00 he shows a shot of federer with his racket face opening at contact on a above center hit http://www.youtube.com/watch?v=U6icR4QaI84#t=3m00s of course he believes that pros deliberately hit below center so that the ball can turn the racket over... Last edited by dominikk1985 : 01-11-2013 at 01:34 PM. |
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#34 |
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Semi-Pro
Join Date: Jul 2009
Posts: 628
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The racket face is slightly closed on 'normal' rally shots to compensate for the spin of the incoming ball. To hit the ball back, with spin, the spin of the incoming ball must be reversed.
in a normal tennis shot, even if the ball travels with no spin, the ball will have spin once it bounces off the court. So in a vast majority of shots you always deal with having to reverse the spin. it has been noted that if you were to hit a dropped ball, which just bounces up with no spin, you would want to hit it with racket that is not tilted. This is all nicely discussed in this book http://www.amazon.com/Physics-Techno.../dp/0972275908 obviously players may not be aware of any of the physics. they just know it through experience acquired over thousands of hours spent hitting the ball. |
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#35 | |
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Legend
Join Date: Mar 2008
Posts: 7,371
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Quote:
ball? And for PP, not any passive aggressive with my clipping above : )
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************ MTM Instructor -Pro Supex Big Ace |
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#36 |
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Semi-Pro
Join Date: Jul 2009
Posts: 628
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#37 | |
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Hall Of Fame
Join Date: Mar 2011
Location: San Diego
Posts: 2,243
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Quote:
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Yonex VCore 100s - SW 351 6pts HL Tour Bite / N.VY 16 @ 51lbs |
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#38 |
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Hall Of Fame
Join Date: Feb 2011
Posts: 2,808
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No.
If it was internal shoulder rotation or pronation this would not happen so suddenly. also internal rotation also closes the racket face when the racket and forearm are in line. however pros hit the ball with the wrist laid back which means the racket is staying at roughly the same angle but rotating around the arm. Test for yourself. take your racket and internally rotate the arm with the wrist laid back and then with the wrist and racket being in line. only in one case the racket will close. also why is feds racket face opening in the video at 3:00 when his arm is internally rotating? Internal rotation of the arm is very important because in greatly contributes to RHS but it doesn't close the racket face. |
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#39 |
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Legend
Join Date: Mar 2008
Posts: 7,371
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Well, at least not that fast anyway.
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************ MTM Instructor -Pro Supex Big Ace |
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#40 |
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Hall Of Fame
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