Where the Federer's ball goes?

[marcolisa]

Dear John, your article about Federer forehand is...............FANTASTIC.

In my opinion, you must relate all the wonderful analisis, also,
to where Roger is going to send the ball on the various footages.
I am sorry if I ask something about this wonderful article.
But I feel that this part, where he is going to send the ball, is missing.

Anyone else share with me this opinion?

Marco.

[brieno2003]

Yes, I definitely agree with that. I also think it has to do with the spin on the ball that is approaching him, how high the ball is, what surface he is playing on, and possibly even the direction of the wind.

The tv commentators tend to pick out one follow through of Federer's forehand and talk (every week) as if that is his only follow through. I'm glad this analysis went infinitely deeper than the commentators, but I still believe there is much more to analyze.

Thanks for the post.

[johnyandell]

Gentlemen,

We are all three in agreement. That is actually my view of the limitations of the articles as well--the fact that the technical patterns aren't specifically connected to actual shot locations, spins, trajectories. And that's the next step to try to plot. If we had tape of Federer's matches from Canada last year--that would give us a resource. but I'm not sure how much was televised and it was mainly Canadian anyway in the early rounds we filmed.

In the past we have tried to film with one additional high camera for shot location, but haven't been able to pull off the logistics--we might try that again too.

We are also doing some spin/speed analysis. We have some raw spin data about Federer--and some other top players. What we found may surprise you--it did me, about the amount of spin Roger is generating--more on that later. We are also trying cooridinate that spin data with some data from the shot spot guys on speed, location, trajectory.

This could help with the missing pieces. My feeling is not that there is much more to learn, but that we are just getting started!

John Yandell

[marcolisa]

Dear John, I want to underline that mine is not absolutely a critic.
Maybe it will be enough, to write on the captions under the footages,
a phrase like " this ball landed is in topspin near the baseline " or
" this ball is going very flat on the backhand side....... "
maybe a rough indication will be useful.

I am sure that for you to add a camera to shot location it could be a problem.
And probably is not useful.
I agree that it is much more important to read your analisis about speed / spin / trajectory, my " idea " is that we dont know where the ball will land.

I could presume that this is also the doubt of brieno2003.
Marco.

[johnyandell]

Don't worry I understand. What we have done so far is obviously way beyond what was previously known. But I think the location thing is the next step. There is still a ton I don't fully understand myself and I plan to.

[ruymendes]

Another step

Another question. The videos now available already show a lot of action, that is, they last about ten seconds, I suppose. With the technology under use, isn´t possible to extend the duration of the videos, in order to be possible to show as well the reply of the original shot, using a panoramic camera?

[johnyandell]

Not sure I completely understand the question, but... The average stroke lasts a little over a second in pro tennis--it just looks slow in the high speed footage! Seeing the reply would require a second camera. It is impossible to pan back and forth between the players--we've tried! Just happens way too fast for even the best cameramen in sports--and we've had some.