Interactive Forum: October 2012 - Juan Martin Del Potro Forehand

[don_budge]

Del Potro vs. Nadal...Indian Wells 2013

D_B has a valid point. With today's equipment, Borg could have gotten away with dropping the racket a little lower with his wrist and added more internal rotation and added even more topspin. As it was, he still framed a lot more balls than most. I only got to hit with him once warming up for the WCT Munich in '75 for a few minutes so I can't really say, but the way I heard it was guys' shoulders would be sore having to hit so many high bouncing balls against him. Just imagine what he would have been with today's equipment.

don

I wonder what Del Potro's chances are against Nadal tonight. I guess that you can't rule him out seeing as he just deposed the hottest player in the world. But is it too much to hope for?

I thought Don's comment was interesting so I quoted him just for the fun of it. I wonder how it was that McEnroe was the one to finally neutralize the Swede's topspin. Is the same thing possible today against all of the topspin Titans?

[stroke]

I feel like his straight arm technique allows him to take advantage of that high strike zone more than he otherwise could with a bent arm technique. His forehand to me is right up there with Fererer and Nadal as the best in tennis.

[10splayer]

Anyone else notice that Delpo shortchanges the stretch with the left hand, especially when he is on the move. But could he possibly hit it any bigger? He hit one at 104 today!!

don

Yeah, he can really hit it, in spite of it looking a bit odd. A classic case of talent shining through, and making it work.

However, I wouldn't put too much stock in the 104 number, as ball speed without a spin rate paints an incomplete picture. I"m sure all those guys can hit it north of 100 MPH if it comes at the expense of spin. It just so happens that DelPo, (because of his incredible high strike zone) can hit MORE balls flat and get away with it. He will always be amongst the leaders in ball speed.

[tennis_chiro]

Del Potro's left hand

Anyone else notice that Delpo shortchanges the stretch with the left hand, especially when he is on the move. But could he possibly hit it any bigger? He hit one at 104 today!!

don

[10splayer]

I do believe there are two "paths" as i consider the windshield wiper action to be an "independent variable". One "path" would be how steep or shallow the arm treks forward to the ball, and the other path being how steep or shallow the racquet head rotates up and around the hand.....These two elements can be mixed and matched in a multitude of ways.

In the Del Po video, I do not see a huge disparity in the way the hand treks the ball one from the other.(to account for the spin difference) The hand is moving on a relatively shallow path. The real difference is how much more the racquet tip is rotated up in the high spin shot.....This "second path" steepens the approach angle (spin) without it coming at the expense of ball velocity...

[tennis_chiro]

One swing can only be shallow or deep

I really do NOT understand your original post plus the follow-up exchange
There are TWO components
in

http://www.youtube.com/watch?v=lPBM-hE1Dhw

Both of them contribute to spin
The flip before 0:08/0:12 is "THE QUICK/DEEPER" component
The continuation AFTER is a "SHALLOWER" component
Please let me me know whether this post of mine is clear
Julian
PS I have a British spelling of my first name.
PS MY clip is about backhand but it does NOT matter

Julian,
at least in this discussion, one swing can only be shallow or deep. In your Djokovic backhand example, his racket reaches it's lowest point 19 mouse clicks past where the clock reads 00:07. This is a little past where the overlaid graphic tries to indicate the lowpoint of the swing. I would say this swing is fairly "deep" although the graphic makes it look as if it is not really that deep. The path we are trying to consider "deep" or "shallow" in your Djoker clip goes at its bottom at 00:07:19 to 00:08:14 at contact and continues up.

The point I think 10sPlayer is making very nicely is that with the wiper technique to enhance spin today's player is able to approach the ball with a much shallower sloped approach path and thereby impart more linear momentum in the direction of the other side of the net. However, how different is Borg's stroke?

http://www.tennisplayer.net/members/strokearchive/modern_legends/bjornborg/bb_forehand/bborg_forehand.html?BBFHWideFront.mov

D_B has a valid point. With today's equipment, Borg could have gotten away with dropping the racket a little lower with his wrist and added more internal rotation and added even more topspin. As it was, he still framed a lot more balls than most. I only got to hit with him once warming up for the WCT Munich in '75 for a few minutes so I can't really say, but the way I heard it was guys' shoulders would be sore having to hit so many high bouncing balls against him. Just imagine what he would have been with today's equipment.

Remember, the ball only knows the characteristics of the strings touching it at impact. The more linear arm path is easier to control and time correctly and consistently. The added internal rotation which is described as the "wiper" action (it is not really the wrist, or at least it is very little and almost no flexion, just a little radial deviation) adds just a little spin even as the wrist is trying to keep the strings on the ball as long as possible. Imagine you are swinging a racket with a conveyer-belt-like apparatus in the frame that is whirling a 6 inch wide belt across a 6" wide by 6" high flat surface in the middle of the face of the racket in lieu of the strings. Forget for the moment that that belt might not be as elastic as the strings. Imagine you could run that belt at different speeds. You would certainly get more spin if the belt were going faster, but you would still have to get keep the face of the belt perpendicular to the intended flight of your ball if you wanted to have any success getting the ball where you wanted it to go. The modern day wiper action allows today's players to get more spin even as they maintain the racket face perpendicular to the intended path of the ball for a longer period of time than we could with our strokes that had to finish with the racket pointed at the target.

Well, if you aren't confused now, you aren't really trying... but I kind of like that image of the conveyer belt out there on the end of my racket!

don

[julian1]

I do NOT understand what to explain

Please explain

I do NOT understand what to explain.
Every piece of motion can contribute to the linear speed
AND to the speed of rotation.
You can measure both at the each point of the trajectory.
It looks to me that the spin is generated mainly before 0:08 at "MY" clip.
It is everything what I am claiming.
I have been wrong before
PS

http://tt.tennis-warehouse.com/showthread.php?t=446904

talks about about spin vs velocity for SERVE.
I am NOT sure whether I am helping

[stotty]

Borg and Spin

Certainly not discounting equipment in the equation. Having said that, I would bet a lot of money that Fed could go out there and achieve ball speeds and spin rates much greater than Borg ever could with the same equipment.

Having sat in exactly the same Wimbledon seat, three rows back, (granted, 35 year ago in Borg's case) and watched both men play, I would beg to differ here. Borg hit an incredible amount of topspin with that little Donnay racket. He hit it hard too. I'm sure Federer could hit harder...but with the same spin...with a wooden racket....doubt it. Borg brushed up hard and steep and with far more net clearance than Federer.

I think Borg and Mac took tennis as far as it could go with wooden rackets...maybe Fed with a wooden racket could have taken things a couple of centimetres further, who knows.

Fascinating discussion about Dep Po. I see what you mean about the tip of the racket being "underneath" the hand.

[10splayer]

There are TWO components
in

http://www.youtube.com/watch?v=lPBM-hE1Dhw

Both of them contribute to spin

Please explain

[julian1]

Two components

The "path" would be, how much the the shoulder lifts the arm out to the ball. The "steepness" of the swing....What I'm saying is that in days past, a guy like Borg would swing the racquet upward on a much steeper plane..I've seen numbers in the ball park of an upward 45 to 55 degree slope on an average rally shot. If you contrast that with a guy like Fed (who on average) is only swinging upwards at about 30 degrees.

Now, here's the thing JUlien, if Fed is only swing up at 30 degrees or so, how does one account for the tremendous spin that he creates? The answer in my mind, is the much more pronounced windshield wiping action...this adds more spin regardless of how steep or shallow the arm movement is..an independent variable as it were.

If you isolate the hand path in the del potro videos, I see not much difference..What is different is the position of the racquet tip at the beginning of the forward swing.....The tip is much more "underneath" the hand with the heavier spin shot..

As i mentioned earlier, the player gets the best of both worlds. Because the swing is shallower, they can still retain a lot of ball speed and yet create a tremedous amount of spin with the wiper action..which is why we are seeing laser like, 90 mile balls with upwards of 3000 rpms of spin..

Just my 02 cents.

I really do NOT understand your original post plus the follow-up exchange
There are TWO components
in

http://www.youtube.com/watch?v=lPBM-hE1Dhw

Both of them contribute to spin
The flip before 0:08/0:12 is "THE QUICK/DEEPER" component
The continuation AFTER is a "SHALLOWER" component
Please let me me know whether this post of mine is clear
Julian
PS I have a British spelling of my first name.
PS MY clip is about backhand but it does NOT matter

[10splayer]

Of course...especially if he is hitting the ball "further forward in his stance" to borrow from golf terminology as I referred to his golfing the ball in my post earlier in the thread. Even if he is only hitting the ball two ball positions earlier in the second swing the angle of impact is going to be significant.

It is hard to tell if he is meeting the ball earlier and by how much but to my eye it appears that he is and for me that would account for the increase in spin rate. Ball position relative to the upward trajectory of his swing.

A much bigger "player" in production of topspin, is the counter rotation of the arm in the forward swing (how much).....In the higher spin shot, the shaft of the racquet is pointed much more downward. To achieve more or less a shaft parallel position at impact, the racquet head would have to be rotated up more than on the lower spin shot...more spin. In fact, i think that's the most distinguishing difference in the 2 DEL PO examples....

[don_budge]

Ball position?

Can you see how this would lead to more topspin?

Of course...especially if he is hitting the ball "further forward in his stance" to borrow from golf terminology as I referred to his golfing the ball in my post earlier in the thread. Even if he is only hitting the ball two ball positions earlier in the second swing the angle of impact is going to be significant.

It is hard to tell if he is meeting the ball earlier and by how much but to my eye it appears that he is and for me that would account for the increase in spin rate. Ball position relative to the upward trajectory of his swing.

[10splayer]

Actually just skimmed over the Gordon article again. (i thought he touched on this a bit) Anyway, I think Brian is saying the same thing when he talks about how the "amount of flip determines the counter rotations and orientation of the shaft as the swing progresses forward. The variations in the amount of flip is critical in controlling the amount of spin on any given shot".


The real significance (to me) is that a player need not take a huge uppercut at teh ball to create a high spin rate.

[10splayer]

Very interesting...but I fail to see how the wiper action by itself can account for an increase in spin unless somehow it is related to the equipment and the strings. For example...I doubt that even the Fed with his wiper action forehand would get the big increase in spin using Borg's racquet and strings. He may produce less spin. Is the increase in spin a factor of equipment and strings?

Come to think of it...that might make for an interesting experiment.

Certainly not discounting equipment in the equation. Having said that, I would bet a lot of money that Fed could go out there and achieve ball speeds and spin rates much greater than Borg ever could with the same equipment.
No, I think this is technique oriented.

DB, look at the Del Po video again, and tell me what you see. The real difference as i see it is the position of the racquet tip at the beginning of the forward swing. With the higher spin shot, the forearm is much more supinated and racquet shaft is oriented downward. Can you see how this would lead to more topspin?

[don_budge]

Strings and things...?

The "path" would be, how much the the shoulder lifts the arm out to the ball. The "steepness" of the swing....What I'm saying is that in days past, a guy like Borg would swing the racquet upward on a much steeper plane..I've seen numbers in the ball park of an upward 45 to 55 degree slope on an average rally shot. If you contrast that with a guy like Fed (who on average) is only swinging upwards at about 30 degrees.

Now, here's the thing JUlien, if Fed is only swing up at 30 degrees or so, how does one account for the tremendous spin that he creates? The answer in my mind, is the much more pronounced windshield wiping action...this adds more spin regardless of how steep or shallow the arm movement is..an independent variable as it were.

If you isolate the hand path in the del potro videos, I see not much difference..What is different is the position of the racquet tip at the beginning of the forward swing.....The tip is much more "underneath" the hand with the heavier spin shot..

As i mentioned earlier, the player gets the best of both worlds. Because the swing is shallower, they can still retain a lot of ball speed and yet create a tremedous amount of spin with the wiper action..which is why we are seeing laser like, 90 mile balls with upwards of 3000 rpms of spin..

Just my 02 cents.

Very interesting...but I fail to see how the wiper action by itself can account for an increase in spin unless somehow it is related to the equipment and the strings. For example...I doubt that even the Fed with his wiper action forehand would get the big increase in spin using Borg's racquet and strings. He may produce less spin. Is the increase in spin a factor of equipment and strings?

Come to think of it...that might make for an interesting experiment.