Discussion in 'Tennis Tips/Instruction' started by drakulie, Sep 19, 2006.
Check P. 25 in Technical tennis if you want some supporting text.
Yes, it states that racket speed is typically 1 to 1.4 ratio to speed velocity, but what they mean by the "racket velocity" is not the velocity at the tip of the frame, but at the impact area.
Some more developments on my serving:
1. I found that instead of just bending the knees they should be "kicked out"! Its hard to explain, but basically instead of worrying about compressing the legs I'm throwing the knees out in front on the swing back from the initial weight transfer to the rear foot (from front).
It looks like a person slips on some ice where the legs are sliding forward leaving the body falling, only here its not the feet but the knees.
This component didn't so much add the pace to my serves as made it more fluid and consistent.
2. This one has really added some smooth violence to my serve - I noticed from my vids ( http://www.youtube.com/watch?v=2Tz_vhrWJRs ) that I was flicking my left hand downwards and not getting the tuck-in bend of the arm until well into shoulder rotation - so my left arm was getting in the way of rotation - so instead, I worked on keeping the palm open after the toss and bringing it in right before shoulder rotation is to begin, so this way that motion would add to it.
The funny thing is I noticed Pete Sampras doing the same thing as I was with almost no arm fold in and a flick of the hand down right before serving :shock: !
You can see how his rotation stops short because of it.
Compare that to Roddik's aggressive arm-fold BEFORE the rotation begins
Did I just find Roddik's secret ingredient to his not-so-secret weapon?
anton, good stuff. Thanks for sharing all that info.
Served some more yesterday with the radar, got some footage with time.
First two serves I moved the arm down but didn't really bend it.
The third one, I do start the rotation with the left arm bend-in and its obvious my torso rotated quicker, too bad I didn't really have my jump timed correctly and I took the ball too low and too close to the baseline.
Here is the slow mo:
DRAKULIE:when are you going to put up a new vieo drak?
ANTON:Could you film your serve straight from behind like Drakulie, it's hard to gauge the speed with the camera moving.
Anton: I'm sure you've noticed, but just to give you a heads up, you step over the baseline occasionally on your final step with your left foot!
Yea I noticed the small double-hopping I'm doing - I've been ridding myself of it for a while now, used to be a lot worse
But I don't think I've actually crossed the line prior to impact in any of these...maybe the last one ever so slightly
Anton, good stuff. I like the way you are documenting the changes/improvement you are making on your serve. Thanks for sharing.Has it been difficult making these small changes??
BeHappy, just haven't had the time to go out and video.
BTW, Anton provided the speed. Just look at the radar.
the radar gun was juiced....
I didn't see a calibration of it....
Anton you need to work on your serve toss.
You are taking a last step with your left leg as wbf noticed but it is an effort
to compensate for an eratic ball toss.
You are trying to reach for the ball. In the last serve for example your foot
moved to the right (that's where your ball toss was) whereas in the one before that
it hardy moved at all(better ball toss). This last step takes a lot of power and control of your serve.
You also slide the left foot backwards just before tossing the ball (last serve)
because of the huge step you take with your right foot backwards in order
to trigger your service action.
Keep your left foot where it is. You should "roll" on it but not move it around.
Anton, not to be picky but I noticed you doing two small steps while serving. Isn't that illegal? Aren't you only allowed one step per serve while serving ?
Don't worry drakulie.. i think your serves sexy!
Not sure about that rule, but not every little motion of the foot counts as a step. Almost everyone makes a slight foot motions throughout the serve
Thanks for the feedback - I'll keep it in mind for my next session
nice video anton. interesting motion. some good pace!
LOL, thanks Josherer.
Anton, have you found it difficult incoorporating all these small changes you are doing with your serve??
drakulie, i can't believe ppl were doubting your 100mph serve.
I attempted returning some 120-130mph servers from a local pro that does NIke tennis camps (nike headquarters is based close to wear i live).
most of the time I had to jump away to protect myself...more importantly my juevos/pelotas/progeny.
most of the time i couldn't even tell if it was in or out... even his second serve i had a hard time seeing. when his second serve bounced right in my striking zone I could hit an OK return back to him. this was with a full swing. he said i shouldn't be trying to take full swipes to return the serve...just to poke at it kinda. block it back.
but yeah...it was scary stuff and I dunno if I could ever return serves that fast.
can't believe some women can serve that fast -.-
wow i stole your avatar...sorry mang. i'll find myself a new one
Hyogen, as for believing the speed of the serve, everything looks much slower on video. Those serves are actually around 110-111 mph. I have played a bunch of posters on the boards, most recently, Sup2Dresq who is nationally ranked. After he met me, someone on the boards asked him if I really served over 100, and he responded that my serve was well over 100. Here is the post:
As the pro told you, the best thing to do is to have a short takeback and forward swing (as if blocking) forward.
Good luck with that.
In love all is easy! :twisted:
In this case I do some weekly serving sessions, at at least half-hour each, pay attention to the details, and never be too satisfied.
But the difference clearly comes out as months go by...sometimes quicker sometimes slower, sometimes you even go back a step.
It's tough to say for any particular element - you can be trying to work on something seemingly simple for hours and not get anywhere and maybe another day you take a swing and something just clicks and you instantly capture the feel.
wow... watching sampras' serve slow mo.......he only is using his left foot to push off the ground and leap upwards!!!!!! check it out :O
Which radar do u use?
Which radar do u use?
Evaluation of serve
You may consider to send a video to tennisplayer.net for evaluation of serve
The speed track.
Ok the proper technique can give even a short guy a ability to serve bombs. Perfect example is Alex Clayton of Stanford, he has the biggest and most devastating serve in division 1 tennis and he is not the tallest guy in division 1. What kind of excercise is best for increasing power and control on the serves ??
Drakulie's serve was definately in the 100 plus range. Look at what happens to the ball after it bounces in the service box!!! It freakin explodes into the back fence area. That ball is moving children. Let the posers come to Miami. I'll bet the Drak can smoke them all.
Practice hitting targets in the service box for control, and practice serving from your knees, or not using your legs to obtain maximum velocity on the swing for power.
LOL. Thanks for checking out the thread and posting. BTW< I'm in Ft. lauderdale now.
You know drakulie, some old friends of mine keep asking me to come out to ft.Lauderdale, so I'm thinking of going there sometime in March or April - would you want to hit some?
hmm, yea good catch, his rear foot stays far from the front.
Absolutely! Alway happy to meet members from the board. Let me know.
^^^ I don't do any of the above. If anything, I would recommend things that will strengthen your shoulder, legs, torso, but make sure it is modest lifting. remember, you are better off being very loose.
I have seen many leg strength exercises with machines in Tennis magazine. I think it has merit. cause the true power of the serves comes from your legs. but i think i hurt my knee doing too much of these last 2 years. I don't have natural oak tree like legs like you, so...
Fedace, I don''t want to discredit the use of the legs in the serve, because they are very important. And having them strong and fit will not hurt>>>>>>>it will definitely help.
However, when I video-taped these service videos, I was barely using my legs (Had a foot injury), and as a result could barley push off the ground.
The power of the serve comes more from a kinetic chain of events starting with the feet, then legs, etc. However, comes more-so from the uncoling of the torso, then shoulders upwrads towards the ball and having a very loose arm.
anyone else notice this and have anything to say about it--technique-wise?
Hyogen, that is not uncommon. He is simply trasitioning his weight from back foot to front foot.
Almost all players do this.
The point of the legs, strength-wise is mostly in the height at the point of impact.
From some calculations I've read - for flatter serves, for every inch gained in the height of the impact you get ~10% more court area to make your shot into.
James Blake himself told me that he think his power on his serves come mostly from the Wrist snap. He said when he doesn't snap his wrist, his serves clock at about 105 or so but when he incorporates the wrist snap, it goes up to 120's.
There is no wrist snap in the serve. It's pronation and the rotation of the forearm. The wrist release naturally after the ball has been struck and left the strings.
But yes, he is correct that he gets most of his pace from that phase of the serve.
I recorded a video some time ago, and I just realized I never uploaded it. Sorry about the crappy quality: The cam wasn't that good, and the angle was even worse.
I used maverick1's formula, but tried to make it even more accurate. Instead of counting the frames, I analized the time elapsed between the contact point and the bounce with an audio editor.
It's really simple: You locate both peaks in the the audiowave, and check the time between 'em. After you got that number, you divide it with your camera's fps (mine was 24 fps) and voilà! You have the exact ammount of frames it took to travel from the racquet to the ground.
In the second serve, according to maverick1's formula, the serve was hit at 117/118 mph.
You guys should try this way. I think it's more accurate than simply counting the frames.
^^That serve is sick. Thanks for sharing that Andres. Much better than the "chair" serve you first loaded a while back.
Shhhh. That chair serve is a classic
I tried this software and actually not impressed with it. I sure would not pay 150 US for it. The sound graph appears to be sampled at .032 seconds but the frame rate is 29.97 fps which does not line up?? (confused). I tried to use my videos but for some reason it will not read the codec I used even though they are avi files. So, I loaded up Drake’s .mov video that shows a 101 radar reading. If I use the sound spike as the start time and use what appears to be the court contact from the video (no contact sound spike), I get 13.4 frames. Just using the video I guessimated 13.5 frames (btw the software locks at one frame for two frames (two right arrow pushes) but the time scale moves??). If I use the distance traveled to 58.5’ (just a guess since I can not see were he is standing on the baseline??) I get 104.78 mph If I use 59’ I get 105.82mph. If this software is not really off by a frame, add a frame and sub about 5mph.
That seems reasonable, 101 at the net, 105-106 avg velocity via frame count, and one would guess around 111 off the racquet face as would be measured by pro radar.
Light travels almost instantly, sound travels at 335 meters per second, so if you go by sound you have to add (~.05?) seconds to the time as the racket impact sound will be slightly more delayed then the landing sound.
FPS method should be more accurate.
BTW niice serve
No, it wouldn't, because I'm not comparing the image with the sound. I'm comparing the sound with another part of the same sound.
If there's a delay between the actual hit, and the hit audio peak, it's the same delay between the actual bounce, and the bounce audio peak. Therefore, there is no delay in this method.
Plus, I AM using FPS to calculate it. Just doing it more accurately. Instead of using 10 frames or 11, I have a way to measure 10.381 fps, impossible to do by SIGHT.
Not the same sound, the point of impact is about 15 meters further away from the mic then the point of landing that should make for about .05 second difference,
Actually the speed cal give Vo=Vpeak=Vmax. It provides the maximum velocity not an average. There is significant possible error with the distance and frame count provided to the formula. It appears the radar and the formula is close in readings in this case.
This is correct. There will be a Doppler effect. With this formula if you want a get a very accurate reading a high frame rate camera should be used along with measuring the distance on court with a string between the contact zones. I would actually like to do this experiment with high speed video and compare the readings to an ATP radar setup. Would be interesting to see the results.
Nice looking serve Andres. Please tell me that wasn't a second serve
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