5263
G.O.A.T.
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.
The Forehand: Busting misconceptions once and for all
- Thread starter 10isfreak
- Start date
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.
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.
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.
5263
G.O.A.T.
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.
5263
G.O.A.T.
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.
5263
G.O.A.T.
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.
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.
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.
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.)
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.)
10isfreak
Semi-Pro
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.
10isfreak
Semi-Pro
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.
10isfreak
Semi-Pro
IMO if ball digs into strings, they work as traditional clasp brake, so they can stop ball rotation.
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.
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.
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Everything happens in that time.
5263
G.O.A.T.
Exactly right.
5263
G.O.A.T.
full of good info here!
dominikk1985
Legend
Do you think that those guys intentionally hit the ball below the center?
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.
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
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.
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.
Chas Tennis
G.O.A.T.
Racket oriented news story -
http://www.nytimes.com/2012/08/27/s...nis-racket-put-new-spin-on-the-game.html?_r=0
Some articles with older references, latest references about 2002 or so. Forehands have changed.
1) Knudson & Elliott chapter, starts on page 150?
http://books.google.com/books?id=ZL...q=elliott forehand closed racket face&f=false
2) http://www.coachesinfo.com/index.ph...e&catid=95:tennis-general-articles&Itemid=173
3) http://www.coachesinfo.com/index.ph...e&catid=95:tennis-general-articles&Itemid=173
Videos of ball impacts
http://www.youtube.com/watch?v=O2wMPW_ivBo
http://www.youtube.com/user/ITFTechnical/videos
http://www.youtube.com/watch?v=tNUBmOt2gOU
Spaghetti strings
http://engineeringsport.co.uk/2010/01/19/revenge-of-the-spaghetti-strings/
http://www.nytimes.com/2012/08/27/s...nis-racket-put-new-spin-on-the-game.html?_r=0
Some articles with older references, latest references about 2002 or so. Forehands have changed.
1) Knudson & Elliott chapter, starts on page 150?
http://books.google.com/books?id=ZL...q=elliott forehand closed racket face&f=false
2) http://www.coachesinfo.com/index.ph...e&catid=95:tennis-general-articles&Itemid=173
3) http://www.coachesinfo.com/index.ph...e&catid=95:tennis-general-articles&Itemid=173
Videos of ball impacts
http://www.youtube.com/watch?v=O2wMPW_ivBo
http://www.youtube.com/user/ITFTechnical/videos
http://www.youtube.com/watch?v=tNUBmOt2gOU
Spaghetti strings
http://engineeringsport.co.uk/2010/01/19/revenge-of-the-spaghetti-strings/
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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.
tennisfan69
New User
Suresh, do pros use low tension? any idea for tension ranges? thanks for the info.
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.
Off The Wall
Semi-Pro
This is not by accident. Advanced players prefer to hit there.
yeah, certainly doesn't need a 'study' for this..... it's pretty straight forward 7th grade physics stuff
10isfreak
Semi-Pro
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.
huh? what makes that hissing sound when you hit a spin serve, or when you cut a heavy slice? (if you have experienced either)
10isfreak
Semi-Pro
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.
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.
10isfreak
Semi-Pro
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.
bad_call
Legend
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.
Povl Carstensen
Legend
I do not think the strings move several inches. More like, half an inch?
Povl Carstensen
Legend
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.
Geology_Rocks!
Semi-Pro
I wanna see this film.
TW Staff
Administrator
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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.
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.
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.
Wegner
Rookie
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.
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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.
Wegner
Rookie
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!
Wegner
Rookie
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.
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.
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.
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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