Interactive Forum July 2023 Jannik Sinner Serve

[johnyandell]

Interactive Forum July 2023 Jannik Sinner Serve

Here is a gorgeous frame by frame slow motion clip of Jannik Sinner’s first serve created by Jim Fawcette. Notice the platform stance, the timing of the racket on the windup, the deep knee bend, the timing of the racket entry into the backswing, the contact point, and the full rotation of the hand arm and racket in the followthrough.

No wonder it’s a great serve! But what else do you see?

[mp4t]https://www.tennisplayer.net/members/forum/2023/July_SinnerServeDeuce_IW23.mp4[/mp4t]

[jeffreycounts]

Jim - how many frames a second is that? It's spectacular!

[jimlosaltos]

Jim - how many frames a second is that? It's spectacular!

Thanks a lot! Appreciate it.

More tomorrow when I'm on a real keyboard, but short version 120 frames per second. BUT those frames were shot as still images, which requires explanation. To come.

But I think it provides some good insight into Jannik's serve.

[jimlosaltos]

Jim - how many frames a second is that? It's spectacular!

Jeffrey, at the risk of providing more than you're interested in, it was shot at 120 fps. But this was still photography, which I converted into video afterwards, so it's not exactly analogous.

I was experimenting with this format when I did this and some of the prior videos of Sabalenka and Medvedev. I normally don't just hold the button down and try to capture something, derisively called "spray and pray" or "press and spray". But my then-new camera is so darned good at it, so I'm testing what that's useful for.

The other "conventional" videos I shot of Sabalenka and Medvedev were shot at 4k/ 120 fps. When played back at 20 fps, it then slows down the action 6x.

With this video made from still images, I first edited the images for color, sharpness, exposure in Lightroom, then imported them to a video editor, Final Cut Pro X. There I set the "duration" that each picture is played subjectively. Long-winded but the point is I don't know exactly how much it was slowed down. I'd guess about 10-12X? So, it is more like shooting video at 200-250 fps in terms of how much the action is slowed down.

Among several differences for anyone that actually read this far: With video, one normally doesn't use shutter speeds of more than twice, the frame rate. So, 120 fps video is shot at 1/250th of a second shutter speed. Using a higher shutter speed to stop the action, results in a jerky image. With video, one usually wants a smooth, "cinematic look" that we're trained to expect. But these stills were shot at 1/2500 th of a second to freeze the action, contributing to the "stop action" look.

Seems to work for tennis with an audience that wants to see the details of a stroke. But it is a lot more work.

P.S. I also used a camera feature called "pre-capture". The camera buffers images as you hold down the shutter button. I tried to capture the moment of impact, as I might with an individual shot. When I pressed the shutter button anticipating the racket hitting the ball, the camera saved that image plus the prior 1/2 second of shots and kept taking them until I lifted my finger. Gets the moment of impact, plus shots before and after.

Sorry you asked ?

[jimlosaltos]

Here are a pair of still photos that might add. I've posted at least one of these before, but hope they're helpful here.
These are from different serves, not the one in the video.

Look at the knee bend. Guy is 6 ft 4 in or so and the bottom of his knee cap is just about the top of his sock, what, 10- 12 inches off the ground?

filedata/fetch?id=101318&d=1688229998&type=thumb

And here is the moment of impact. Jannik is fully rotated and ball is well to his left of his head -- even more so than in the serve in the video.

filedata/fetch?id=101319&d=1688229998&type=thumb

#

[stotty]

I can't view the clip for some reason. The photos are super. He seems to have a very deep knee bend.

[jimlosaltos]

I can't view the clip for some reason. The photos are super. He seems to have a very deep knee bend.

Hmmm. Plays for me in Safari. There is a pause at the beginning to allow people to read the titles, but that's just a couple of seconds.

Retried a couple of times just now. There was a lack of response one time when I clicked the small "Arrow" to play. You might try clicking in the middle of the image, which has worked every time for me.

[stotty]

Hmmm. Plays for me in Safari. There is a pause at the beginning to allow people to read the titles, but that's just a couple of seconds.

Retried a couple of times just now. There was a lack of response one time when I clicked the small "Arrow" to play. You might try clicking in the middle of the image, which has worked every time for me.

Ok clicking the centre of the image worked. Seems there's no end to your skills or energy when it comes to these things. I just love the video and its 'stop action' look. Sinner really drives up, doesn't he? And keeps his eyes glued to the ball.

[jimlosaltos]

Ok clicking the centre of the image worked. Seems there's no end to your skills or energy when it comes to these things. I just love the video and its 'stop action' look. Sinner really drives up, doesn't he? And keeps his eyes glued to the ball.

And I do remote IT Support as well <g>. Glad to help -- and glad you like the vid.

[jimlosaltos]

Since I'm avoiding chores as it hits 97 deg F outside here, let's litter TPN's servers with more bits.

The many fans of Internal Shoulder Rotation, and I know there are a lot of you here, should admire this one. What's striking to me is that Jannik gets to almost his full rotation while his racket is pointed so high, which tells me he turned his arm really fast.

It continues to rotate just a bit further after this but by then he's started "ulner flexion". I've never understood why some servers twist their forearm down severely while others, like Fed, I can't recall doing that all.

Caption: Sinner again from Indian Wells last March. This from a low res jpeg burst All. (c)jfawcette aka me.

filedata/fetch?id=101327&d=1688249735&type=thumb

[doctorhl]

Jim and JY: At the moment of impact on Jim's post #5 in this thread, if you dropped a plumb line from the center of racket face to the ground, can you guestimate how far into the court the plumb would drop? I am not fully appreciating the amount of sidebend and back arch needed, and where exactly on his toss arc contact was made. I also am having trouble appreciating the amount of external rotation needed when the shoulder angle appears to be about 90 degrees flexed while elbow is at 110 degrees in second 42 of the video.. I dont think even at birth I was that flexible! I know JY and Brian Gordon have discussed this, I just need to find it. Would be Sinner considered average or an outlier for ESR and back arch?

[doctorhl]

Your beautiful still on post #10 also demonstrates that Sinner's ISR after contact is also pretty good?

[dimbleby69]

Unexpected ingredient to the discussion.

Just watched Sinner win the final set of his 6-2 6-2 6-2 first round victory at Wimbledon.

He was serving pin-point. J McEnroe was commentating. Didn't mention the change during the 3rd set but might have done earlier.

I'm left scratching my head. He sometimes seemed to me to be rushing his motion somewhat, the pinpoint added to the impression.

Is this a temporary fix for an injury problem? Have I missed something about it elsewhere?

regards
Rob

[stotty]

Unexpected ingredient to the discussion.

Just watched Sinner win the final set of his 6-2 6-2 6-2 first round victory at Wimbledon.

He was serving pin-point. J McEnroe was commentating. Didn't mention the change during the 3rd set but might have done earlier.

I'm left scratching my head. He sometimes seemed to me to be rushing his motion somewhat, the pinpoint added to the impression.

Is this a temporary fix for an injury problem? Have I missed something about it elsewhere?

regards
Rob

Well, that's interesting if he has reverted back to pin-point. Many players do revert back to pinpoint after trying platform for a while. I tried to find the match on replay but couldn't find it.

[don_budge]

Unexpected ingredient to the discussion.

Just watched Sinner win the final set of his 6-2 6-2 6-2 first round victory at Wimbledon.

He was serving pin-point. J McEnroe was commentating. Didn't mention the change during the 3rd set but might have done earlier.

I'm left scratching my head. He sometimes seemed to me to be rushing his motion somewhat, the pinpoint added to the impression.

Is this a temporary fix for an injury problem? Have I missed something about it elsewhere?

regards
Rob

I noticed that in Halle...but didn't want to wake anybody up.