Federer Racket Drop

[JoeD]

John,

You probably considered this, but just in case.

Re: your Roger's serve article (by the way, VERY well done!) and the section on the degree of racquet drop comparing Roger's to Pete and Andy

Why did you only compare the angle of the forearm to the court. Seems to me that at this stage the upward momentum has already begun. Did you consider seeing where the lower point of the tip of the racquet is? Maybe I am missing something???

Look at the tip of the racquet relative to the player's waist in the motions of each. Seems to me that Roger's "swing length" (assuming swing length potentially = racquet head speed). Roger's is pretty darn far and long. It seems to be just further back because of his more circular preparation.

Of course, you are comparing "external rotation" (whatever that really means and whatever effect that really has on racquet head speed). Am I overly simplifying it by thinking that swing length is equally or more important to generate racquet head speed? Does centrifigal force play a role here vs the more vertical acceleration you wrote about?

BTW, boy doesn't the tip of the racquet on Mark P's serve drop lower than all the others listed? Seems that way.

Good stuff clarifying the wrist action!



Joe Dinoffer

[johnyandell]

An excellent point and question(s). Ladies and gentlemen--this is posed by Joe Dinofer himself from On Court/Offcourt. He does high level speaking at the national coaching conventions as well as creating all that cool stuff for teaching pros.

He will be contributing articles later this year. He and I share a certain fascination (not to say obsession) with some of these thorny issues based on looking at the high speed footage.

What I think is the lowest point for Federer is higher than the other guys--due to the external rotation--or more limited amount thereof .

Here is one of the high speed clips. Back it up around 12 frames from the contact, that appears to the lowest point. What we really need is Brian Gordon's 3D technology to measure the distances, but eyeballing a lot of clips from a lot of angles of all the servers, I'm pretty sure that Fed's racket doesn't fall as far--or travel as far to the ball. You can see that pretty clearly in the still frame freezes in the article from the high speed video.

External rotation as it has been expalined to me is your ability to rotate your upper arm backwards in the shoulder socket. Now if you externally rotate more then when you swing up to the ball you will internally rotate more--and that is a big factor in racket speed.

The reason Philippoussis has that great drop with the ciruclar windup isn't just because of the cirular windup--it's because he can rotate his upper arm back and then forward like Pete and Andy.

Check out the clip of Wayne Arthurs in the Paul Goldstein analysis to watch this in another guy with a scary shoulder joint.

Now the average player can let the racket fall along the side of the body better with a circular windup--so the path will be directly up which I think is important since all the top players do it. BUT the length of the path will be less because they lack this bionic flexibility.

It's interesting to speculate on the role of "length" in racket head speed. If you look at Brian Gordon numbers you can look at it a different way--it's extension, rotation, and forward wrist movement (but not "snap" right?)

Now would those elements contribute more and would the absolute value be higher with a lower racket position and a longer path? Good question. One would think yes--and that is what I see with Roddick, Flipper and Pete--a longer path and definitely more forward (internal) shoulder rotation.

Ultimately I think it's a matter of positions--make the pro drop or as close to it as you can. Have the right ball position (next article) right contact and finish, and you will have the racket head speed god intends for you. If you can't get a deeper drop that's just the way it is. Works out OK for Roger don't you think?

And that's my point. With that windup path (or maybe better yet Mark's) most players can approach this position.

[moderntennis]

Great article, John - I appreciate your scientific approach, changing a hypothesis to fit the incoming data as opposed to attempting to stubbornly shoehorn facts to fit theories. As you point out, knowledge is always a work in progress.

[robertfirlus]

Does Federer Pronate on Serve

I've heard something about pronation on the serve. That it's good...or the thing to do. I guess it means that the palm turns toward the ground after ball contract...on follow thru....Is Federer doing this....pronation on his serve? It doesn't look as tho he does.

robertfirlus

[johnyandell]

Thanks for the feedback. It gets too boring and tedious trying to find ways to defend your positions--easier to try to evolve I think.

And Robert--pronation means your hand turns toward the right fence! Not down at the ground. Federer pronates as do all good servers to some extent. It's the natural consequence or continuation of the hand and arm rotation described in the article.

[Philip_D]

Philip

Hi, John!

Just wondered if Federer's racket drop is less, partly or wholly because of an earlier acceleration upward with his upper arm?

[johnyandell]

If you look at the video above, the elbow does appear to move upward prior to the deepest part of the drop. but If you look at the amount and speed of the movement, I wouldn't call it acceleration. The higher elbow position let's you get a fuller drop if you can't rotate your arm as far back in the shoulder. To me, that's what I see in the video.

[jhm36]

Hi Guys,

Just wanted to say that I've been experimenting in the last week with a more circular racquet drop and while the results are mixed due to my serve breaking down a bit by my changing something so significant, there's no doubt that the more circular path helps me keep my arm and wrist more loose and relaxed than I had them before.

I've been trying to imitate some of Federer's movement, the leaning forward then rocking back with the backswing and I tell you it feels great to just let your arm and racquet swing backwards as you lean to the fence. It's such a positive reinforment tool, knowing that if I'm really relaxed, when I lean back at the start of the motion I should feel my racquet sweep back towards the fence. If I dont get that 'falling away' feeling, I know I'm not loose enough at the start of the motion.

Staying so loose through the entire service motion is another story, but I'm working on it.

Give it a chance. It might work for you.