Interactive Forum: Jan 2008 The Upward Swing More High Speed Video

[airforce1]

Correction

Many of you probably noticed my misleading comment related to this upward swing piece, relating to it being written on "the Pro level serve", and were too kind to correct me on that.

Looking back over info on the data collection I now realize that the subjects used for data were college players. Clearly very valuable data to study and learn more about the serving motion, but not directly applicable to our conversations on the game's Elite pro servers and how they generate exceptional velocities. This data appears to be an average among the subjects, with no regard or weighting to their ability to generate speed or spin.
Clearly a good approach and we all realize how challenging data collection can be.
This is clearly outstanding work on its focus. I just needed to correct my comment for those who might not have noticed my mistake.

[BrianGordon]

I think what the readers probably noticed is the point of my series seemed to have escaped you.

As to whether the information helps to understand pro technique, I'll let the readers decide. The magnitudes of velocities or any parameter measurable are as high as I've seen measured on any pro.

[airforce1]

ouch!

the starting page of this thread--

Tennisplayer has provided 4 more slow motion close ups of the serving arms of top players, all starting 12 frames away from contact.
Is it possible that timing differences may be an important key to increasing serve speed? Does Sampras extend his forearm later than Agassi? Does this contributes to his increased serve speed?
What about the differences between Roddick and Nadal. They have some similarities in their motions, but what accounts for the speed disparity?

Brian, You may be right, as given the topic stated above for this thread, and the "point of your article" you stated in your article-

"My hope is this explanation well shed some light on serve mechanics."
"Nonetheless I believe we have succeeded in highlighting the many factors and choices that go into constructing a high level serve for yourself or for your players."

I'm not sure why your outstanding piece was referenced on this topic. I have been complimentary of your fine work, but just don't see the direct relevance to this thread. Your article, while impressive, does not appear to deal with any issues contrasting an elite server with a mere normal pro level server. And please forgive my enthusiasm for this topic, as I have been conversing with John on racket drop since 2003-2004 time frame and I'm excited to see some of the other members here that have taken an interest. Even though John wrote an excellent article in 2005 relating to Sampras racket drop, and it is constantly mentioned in "your strokes", he still appears to be less than convinced of it's importance as the difference maker for an elite server.

Of course this is why forums are here; so we can ask questions, point out observations and share info. Maybe you will take the time to show me the point of your article that has "escaped" me as it relates to this thread.
thank you,

[julian]

lateral trunk tilt of tour players

I think what the readers probably noticed is the point of my series seemed to have escaped you.

As to whether the information helps to understand pro technique, I'll let the readers decide. The magnitudes of velocities or any parameter measurable are as high as I've seen measured on any pro.

Question:
Does anybody know data/numbers of lateral trunk tilt for tour players?
It should NOT be very difficult to get this number using Dartfish.
Does anybody know how large is a contribution of flexion
to a speed of a racket for tour players ?

[johnyandell]

I would be circumspect about doing any quantitative measurements off a one dimensional camera view.