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fallguy012
06-15-2005, 08:29 AM
Hi guys,

I need opinions from you guys. When I see pictures of pros hitting the ball, their racquet face angles are littlebit more closed then perpendicular to the ground at impact. Is this how one's supposed to hit the ball? Thanks for the input!

tom-selleck
06-15-2005, 08:38 AM
this is one of my pet subjects...... some people on here say it's impossible to hit the ball with a moderately closed face, but i see it every time i watch.

i'm especially curious as to the angle of the racquet face on the serve.

pretty obvious to me that you can hit the ball over the next with a very closed racquet face because the strings "grab" the ball or to put another way strong friction between strings and ball.

i had a huge breakthrough on my serve when i got away from the idea that the racquet face should be square to the direction you want to hit the ball.

Bungalo Bill
06-15-2005, 08:45 AM
Hi guys,

I need opinions from you guys. When I see pictures of pros hitting the ball, their racquet face angles are littlebit more closed then perpendicular to the ground at impact. Is this how one's supposed to hit the ball? Thanks for the input!

YOu will see slightly closed or square depending on the precise picture frame used and what the player is doing. Both are fine.

Grimjack
06-15-2005, 08:48 AM
This can be a tad misleading. During a swing -- ESPECIALLY a modern W/SW swing on the FH side -- the racquet face will close up as the follow through progresses. Since the racquet face is going the same direction as the ball, it stays VERY close to (and indeed, in contact with) the ball for a small portion of its forward travel. During that time, the face can close up a bit, and give the appearance of having struck the ball while closed, if you only see a still photo.

Still, the fact is the face is generally almost exactly square at the initial moment of contact. Only very slight variations are possible in order to create a driving, forward shot. As the swing progresses, the racquet face may close before the ball appears to have fully departed from the general area of the string bed. But the forward momentum is already imparted.

The appearance of varying degrees of open-ness or closed-ness depends mostly upon which micro-second the photo was actually taken. The same can be said of the slice BH and the open face. At contact -- square; before ball's full departure from stringbed area -- open. This creates a lot of confusion, even among serious players and instructors.

So what you're probably seeing are stills taken after the intial moment of contact, but before the ball has moved away from the string bed. (During the "dwell" period, or slightly thereafter.)

kevhen
06-15-2005, 08:49 AM
Yeah, my belief is that it's the swing path of the racquet that determines the direction of the ball while the angle of the racquet determines how much spin will be put on the ball. Now you must swing through the ball with decent power to make sure the swing path of the racquet is the main factor in determining the direction of the ball. There may be some combo of swing path and angle of racquet face that really determines direction and spin. It's pretty complicated physics since both racquet and ball are in motion and the ball is spinning and can be rising as well so the angle, pace, and spin of the incoming ball are important variables too. I have not been able to master this kind of forehand topspin western shot but have seen 4.5s and up hit this way with a closed face and heavy spin and pace. But it's hard to see if the racquet is really closed without high speed photos to back it up.

And it might be possible that the racquet does open up on contact on a western forehand so that the face is more perpendicular since photos seem to show that.

But I know on the forehand slice that I hit that the balls comes off based on my swing path and not on the angle of the racquet. I can open up the racquet more to create more spin but if I swing through the ball I can hit it straight ahead with an extremely open 45 degree racquet face but it would be nice to have some video to see if this is true or if I am just swing more down and forward on the ball with a closed face with the faster, more downward swing path creating the extra spin but it doesn't feel like it to me.

Grimjack
06-15-2005, 08:49 AM
(And once again, the caveat: the face MAY contact the ball slightly open or closed, and still produce an effective shot, depending upon the height at which the ball was struck, relative to the net.)

Bungalo Bill
06-15-2005, 09:21 AM
This can be a tad misleading. During a swing -- ESPECIALLY a modern W/SW swing on the FH side -- the racquet face will close up as the follow through progresses. Since the racquet face is going the same direction as the ball, it stays VERY close to (and indeed, in contact with) the ball for a small portion of its forward travel. During that time, the face can close up a bit, and give the appearance of having struck the ball while closed, if you only see a still photo.

Grimjack,

I am going to have to politely disagree with you here. I see what you're trying to say but I dont think you know the whole story behind this. The only thing misleading when looking at a photo is "how" closed the racquet face is at exact contact.

It is clear when you review super slo-motion video that players will make contact with the ball with a slightly closed face with even an Eastern grip. They will also make contact with a square face.

When the ball meets a racquet face that is slightly closed, the distortion of the racquet face at impact tends to render itself square as the ball is on the strings for a very very short time. Because this happens in milliseconds, the followthrough continues and picutres and the human eye can not pick up these precise happenings. So it is true that a racquet face does at times meet the ball when it is slightly closed.

Some pros prefer this. They believe that if they have the racquet angled slightly the impact from the ball will render the face sqaure while the ball dwells on the strings. This is a physics sort of thing and has a lot of truth in it. One of the players we studied that did this almost all the time was Andre Agassi.

Still, the fact is the face is generally almost exactly square at the initial moment of contact. Only very slight variations are possible in order to create a driving, forward shot. As the swing progresses, the racquet face may close before the ball appears to have fully departed from the general area of the string bed. But the forward momentum is already imparted.

Ummm...very confusing. The racquet face CAN be square, slightly open (ex. slice), or slightly closed (ex. topspin) to hit the ball effectively. The slight variations are certainly within the control of the player and many players choose to hit with a slightly closed face either consciously or sub-consciously.

In a nutshell, the face can be slightly closed AT IMPACT because of the racquet face distortion reasons mentioned above and still produce a good shot.

The appearance of varying degrees of open-ness or closed-ness depends mostly upon which micro-second the photo was actually taken. The same can be said of the slice BH and the open face. At contact -- square; before ball's full departure from stringbed area -- open. This creates a lot of confusion, even among serious players and instructors.

Well it is not confusing to me. The "appearance" of varying degrees really do exist and is something we studied in detail at the Vic Braden Tennis College.

So what you're probably seeing are stills taken after the intial moment of contact, but before the ball has moved away from the string bed. (During the "dwell" period, or slightly thereafter.)

Ummmm, I see what your trying to say but this is not really the whole truth and what might be happening for a particular player. From my point of view, it could also be stills slightly BEFORE impact.

The slightly closed face at contact is a reality. So is the square face. With a slightly closed face sometimes a player will hit a tad lower on the ball to add lift.

When you slow it way down to the point where you can see the face distort, you will see.

fallguy012
06-15-2005, 09:25 AM
Thanks for the input guys. Ok then if I need to hit the ball either square or slightly closed, what is the best way to keep the racquet face angle constant? I realize that my racquet face angle changes from shot to shot and is not consistent. Maybe it's my grip that changes. Any thoughts? Thanks guys.

Rickson
06-15-2005, 09:32 AM
A lot of people believe that the face can not be closed at contact if they want to get the ball over the net, I believe that's a crock of sh**. Many players make contact with the ball using a closed face including the best player in the world, Roger Federer. For those who believe that only open to square faces can get the ball over the net and closed faces will lead to shots never going over the net, you've been misled.

Bungalo Bill
06-15-2005, 09:34 AM
Thanks for the input guys. Ok then if I need to hit the ball either square or slightly closed, what is the best way to keep the racquet face angle constant? I realize that my racquet face angle changes from shot to shot and is not consistent. Maybe it's my grip that changes. Any thoughts? Thanks guys.

Could be that your racquet handle moves in your hand and you fail to readjust it for the next shot. But that is a grip/awareness problem not a swing or racquet problem.

A fixed wrist is the key. Locking the wrist with the forearm will help maintain a level or very slightly closed racquet face. For now, I would be concentrating on making contact with a squared face. If there are varying degrees within your ability to do this, itwill be so minor it isn't worth noting.

When you lay back the wrist and lock it there, I am not talking about a rigid wrist. The wrist needs to remain somewhat elastic in nature. But when you swing the racquet back and then forward, the wrist should be firm enough to not allow the racquet head to wobble around out of control. Bring the racquet into the ball concentrating on a square face and then go through the ball.

The wrist needs to be flexible but strong enough to keep the racquet head quiet during the swing and strong enough to hold the racquet face square at impact. During impact, the racquet face will distort and twist and if you hit higher on the strings it will worp (spelling????) back sometimes creating an open face.

In a nutshell, just hit with a square face and dont worry about what pros are doing in a photo.

Tennis Ball Hitter
06-15-2005, 09:41 AM
Getting a little off topic but a question for bungalow bill for interests sake. When you were analysing the super slow mo shots,

was the dwell time longer on slightly open/closed shots? and
was there any noticable racquet angle change during the dwell time? and
how much string deformation was there? [I have seen those still pictures where the ball is a semi/half sphere but it looked like little to no string deformation]

thanks

Bungalo Bill
06-15-2005, 10:08 AM
Getting a little off topic but a question for bungalow bill for interests sake. When you were analysing the super slow mo shots,

1. was the dwell time longer on slightly open/closed shots?

We did not measure dwell time on the strings with different racquet angles. We did measure dwell time from an overall standpoint at impact. Braden found the ball stays on the strings for about four milliseconds. To get an idea of how short that is. It takes longer for your hand sensors to send the signal to the brain to feel the impact that was made when you hit the ball. So anything you do to INFLUENCE the ball is futile and one of the biggest myths in tennis. Hitting the ball with a square face and going low to high is how to hit with topspin. The faster you can swing the more revolutions you can put on the ball. If you try to influence the ball by twisting the racquet or using your wrists, you will be doing nothing. It might look good though!

and
was there any noticable racquet angle change during the dwell time? and
how much string deformation was there? [I have seen those still pictures where the ball is a semi/half sphere but it looked like little to no string deformation]

thanks

1. The racquet face distorts on all shots. The ball distorts on all shots, it is afterall a collision. The distortion in a racquet happens way to fast to pick this up in a picture or on TV. Even slow motion video does not pick it up. You have to slow it way way way down to see the racquet face distort.

The racquet angle does change at impact. Which is why you want to have a firm wrist and a firm grip.

Depending on where the ball hits the racquet on the strings depends on which direction the racquet face distorts. If you hit off-center a lot of distortion happens and can either open the face or close the face during the time the face is in distortion. Twisting is also happening at impact.

A stiffer racquet will have less twisting and will be able to send more energy into the ball. With stiffer racquets you get better directional control because they do not bend back as much compared to a more flexible racquet. However, what you gain in directional control you lose in depth control. Obviously, your swing speed plays a role in this as well. (I learned this many years back visiting Head)

A more flexible racquet will have better depth control but less directional control.

TennsDog
06-15-2005, 11:12 AM
We had quite a long thread going about this a while ago. I believe we decided it is possible and ok to hit with slightly closed due to the friction and racket head path. One cannot get away with hitting very closed, but slightly closed to square work fine. This is not really something to be thinking much about while hitting, though.

kevhen
06-15-2005, 12:12 PM
I would expect a stiffer racquet to twist more on off center hits as it absorbs more energy of the off center struck ball.

tom-selleck
06-15-2005, 12:39 PM
We did not measure dwell time on the strings with different racquet angles. We did measure dwell time from an overall standpoint at impact. Braden found the ball stays on the strings for about four milliseconds. To get an idea of how short that is. It takes longer for your hand sensors to send the signal to the brain to feel the impact that was made when you hit the ball. So anything you do to INFLUENCE the ball is futile and one of the biggest myths in tennis. Hitting the ball with a square face and going low to high is how to hit with topspin. The faster you can swing the more revolutions you can put on the ball. If you try to influence the ball by twisting the racquet or using your wrists, you will be doing nothing. It might look good though!


i partially misunderstand....... if the time on the racquet is that short, is there really enough friction to cause topspin? .... you strings are basically slightly grabbing the ball causing topspin and i would be shocked if that occurs in 4 milliseconds..... i think think you flick your wrist to increase the velocity of the racquet around the time you hit it, i don't think this wrist flick is supposed to be exact to the 4 milliseconds the ball is on your racquet.

can you please elaborate??? appreciate your comments.

kevhen
06-15-2005, 01:08 PM
Wouldn't the wrist flick start before and end after those 4 milliseconds?

TennsDog
06-15-2005, 01:11 PM
Time has nothing to do with friction. The formula for any frictional force is FRICTION = COEFFICIENT OF FRICTION X NORMAL FORCE. The coef. is determined by a lot of things, such as type of string, string pattern, ball fuzz, etc., and the normal force is determined also by string type (elasticity) and the velocity (including direction) of the racket face. Racket head speed for a good topspin forehand is fast and the ball fuzz is really "grippy", if you will, which means there is a tremendous frictional force on the ball in those 4 msec. The ball does not slide on the strings because of it, and, in fact, is why the strings move.

Bungalo Bill
06-15-2005, 01:20 PM
i partially misunderstand....... if the time on the racquet is that short, is there really enough friction to cause topspin? .... you strings are basically slightly grabbing the ball causing topspin and i would be shocked if that occurs in 4 milliseconds..... i think think you flick your wrist to increase the velocity of the racquet around the time you hit it, i don't think this wrist flick is supposed to be exact to the 4 milliseconds the ball is on your racquet.

can you please elaborate??? appreciate your comments.

The strings are grabbing the ball but it is the swing path that skims the ball that creates the spin. In other words, trying to come over the ball to make it have more topspin is not good as it does nothing to influence a ball that has already left your strrings. If anything you will mis-time it and the four milliseconds the ball is on the strings sends it into the net. A firm string bed causes the ball to compress against the strings slightly longer. But slightly in milliseconds terms is very short.

I think you are starting to mix in "stroke mechanics" with "how long the ball stays on the strings". I am sure that dwell time is a give or take around 4 milliseconds but in essence it is a very short time. If you think this way in terms of stroke, you will rely on a more consistent racquet path and go for clean contact and timing to influence the ball more then anything else.

The wrist flick is not something I will comment on as I don't believe it is a good thing for players to do on groundstrokes. I will comment on the wrist release which is a relaxing of the laid back wrist and the wrist returning to a straight position. The wrist release happens slightly before impact so that it is allowed to accelerate the racquet into the ball. You still have to have a decent grip on the racquet to control the twisting that goes on. I wouldnt measure this in milliseconds as this simply needs to be timed slightly before contact. This take practice.

BOTTOM-LINE: If the ball stays on the strings for a very short time and there is little you can add or do when you actually hit the ball to influence it in anyway once it hits the strings, this should help you see that a steady and duplicatable swing path is what you need to focus on. This promotes the fact that a steady swing that focuses on clean contact, timing, and rally speed is essential to becoming an excellent tennis player. When you finally come to the point of believing this, I am confident you will begin seeing awesome results in your tennis game.

TheGreatBernie
06-15-2005, 01:52 PM
I remember the best forehand I've ever hit and it was with a closed racquet face. The contact point with a little bit above center of the ball. That shot had the most top spin and pace compared to any shot I've ever hit in my life. I try and replicate it as often as I can, but the topspin or pace is lacking -- one or the other.

I agree that the racquet does "grab" the ball for a split second, allowing players to drive up for the topspin and giving the ball some lift/

Rickson
06-15-2005, 07:56 PM
I remember the best forehand I've ever hit and it was with a closed racquet face. The contact point with a little bit above center of the ball. That shot had the most top spin and pace compared to any shot I've ever hit in my life. I try and replicate it as often as I can, but the topspin or pace is lacking -- one or the other.

I agree that the racquet does "grab" the ball for a split second, allowing players to drive up for the topspin and giving the ball some lift/
Roger does this forehand shot a lot by hitting with a slightly closed face and hitting close to the top of the ball. The shot definitely gets forward spin, but it has a lot more pace than a traditional loopy topspin forehand because it's more of a line drive shot.

Tennis Ball Hitter
06-15-2005, 10:09 PM
The questions in my first post were not asked to aid me in actually hitting the ball, but purely just to satisfy my curiosity as to what actually happens during impact.

thanks for the info Bungalo Bill.

to further satisfy my curiosity, I was wandering if anyone knows of any places where I can download any super slow mo videos. [I plan to tape wimbledon coming and hopefully they will show some super slow mo of players.]

Marius_Hancu
06-16-2005, 12:09 AM
this has been discussed:

How do they hit their forehand with a so close racquet face? (see pic inside)
http://tt.tennis-warehouse.com/showthread.php?t=44538

Rickson
06-16-2005, 02:17 PM
I'm glad you found the old thread, Marius. Ash Doyle seems to insist that closed face hits will wind up in the net, but I guess he hasn't seen Federer play very often. Ash believes that Federer never uses a closed face on contact, but he shouldn't push what he believes to be true on to others because the fact is that Federer uses a closed face on many of his groundstrokes while Ash claims the pictures are of Federer after he made contact with the ball and that his face was perpendicular at contact. Ash Doyle is just an ignorant poster.

papa
06-16-2005, 05:37 PM
Sometimes what we think were doing and what actually happens can be two very different things. I also think I hit with a slightly closed face but the reality is I probably don't, at least not as much as my brain thinks I do. I like the feeling that I'm "lifting" the ball somewhat on my stroke.

papa
06-16-2005, 05:40 PM
Sometimes what we think were doing and what actually happens can be two very different things. I also think I hit with a slightly closed face but the reality is I probably don't, at least not as much as my brain thinks I do. I do like the feeling that I'm "lifting" the ball somewhat on my stroke.

Rickson
06-16-2005, 06:12 PM
Sometimes what we think were doing and what actually happens can be two very different things. I also think I hit with a slightly closed face but the reality is I probably don't, at least not as much as my brain thinks I do. I like the feeling that I'm "lifting" the ball somewhat on my stroke.
Pops, Federer has been seen on slo mo video using a closed face on contact.

kevhen
06-20-2005, 09:17 AM
http://www.wimbledon.org/en_GB/news/photos/imagepages/2005-06-20/200506201119276679527.html

Looks like this ball would not clear the net if it wasn't coming off at a different angle than the string bed thanks to the upward lift of the swing re-directing the ball during contact.

papa
06-20-2005, 10:25 AM
Pops, Federer has been seen on slo mo video using a closed face on contact.

Yeah, I'm sure your right but his swing speed is really fast, certainly faster than all/most of us.

winks
08-08-2005, 12:10 PM
...the racquet does "grab" the ball for a split second, allowing players to drive up for the topspin and giving the ball some lift/

I agree and I think the pictures that you see just after impact where the angle of the racquet is facing the ground is the essentially the same angle of the racquet on impact. Even though impact lasts only a few milliseconds, the racquet "carries" the ball along it's swing path and the ball leaves the racquet moving upward, with a *LOT* of spin. Check out this pic of HH...

http://arabic.cnn.com/2004/sport/5/27/france.henin/story.henin.jpg~1081946309490919900.jpg

kevhen
08-08-2005, 01:20 PM
Sweet HH mother and queen of the feminine one-handed backhand. If you swing hard enough, the direction of the swing determines the direction of the ball and the angle of the racquet face just determines how much spin will be applied.

Bungalo Bill
08-08-2005, 01:33 PM
...the angle of the racquet face just determines how much spin will be applied...

Kevhen,

This is not true. The angle of the racquet face does not determine how much spin gets applied to the ball.

If I held a racquet still and slanted it downward and a ball hit the strings this would not produce very much spin.

It is racquet speed along a chosen swing path that determines how much spin gets applied to the ball. Ball revolutions (or spin) for a certain effect is primarily governed by racquet head speed.