Interactive Forum March 2012: Sam Stosur's Kick Second Serve

[stroke]

Nice. I noticed in watching video of Dougherty's student Naomi Totka that she finishes even higher than opposite hip. And I do think her signature "sick kick" is powerful yet totally relaxed, spin-loaded and no depth with very sharp angle all on purpose. I saw Michael Llodra, another lefty, do the same thing with great effect in Winston-Salem.

I saw that video also. That girl does have a very nice motion under Pat's tutelage. She is using the technique he teaches in his "Serve MPH" video, which is his latest serve instruction video which kind of builds on, and offers some new ideas to his "Sonic Serve" video.

[DougEng]

Rod Cross wrote a recent article on the physics of the kick serve with some interesting points: http://twu.tennis-warehouse.com/lear.../kickserve.php

Nice find! Great article! Rod does excellent work. However, Rod apparently made an error at the start by saying a kick serve needs to be 100 mph. For example, Stefan Edberg regularly served a kick on his first serve at 85-100 mph. Cross corrects himself at the end of the article saying it's possible to serve a kick at below 80 mph. I suspect a "fingerfehler."

An excellent point is the extra spin applied to the ball on a higher toss. Rod points out a toss 3 feet above contact allows a vertical velocity of 9.5 mph or 780 rpm more spin than a toss at the contact point. Howard Brody also used to argue for a higher toss to add spin. Vic Braden argued for a lower toss to allow accurate of contact point. My feeling is that few players mishit the ball on the 2-3 foot drop so it's better to go with Brody/Cross than Braden. In addition, loading must occur in a shorter time frame with a low toss. I don't think many players can generate significant ground force on a low toss, and would benefit from a higher toss. Hence, almost every touring pro tosses at least 12" higher than contact (average is maybe 18-24" above contact or that's the same as the ball drop).

[jimlosaltos]

yeah ...

The ratio is
the velocity of the ball divided by the number of rotations per sec

Well, yes, but since she hits at up to 120 mph is he saying she should hit with higher velocity, which seems unjustifiable, or is he saying she should hit slower serves?

Or is he saying she doesn't get enough spin (since others say she has the most kick on the tour that doesn't make much sense to me either).

So, what is the criticism exactly?

[julian1]

The ratio

I'm not remotely an expert, but with Stosur's serve clocked at up to 120 mph, and typically 110-115 mph, I don't know what ratio you're seeking. Now "in tennis" is tough. Ryan Harrison has a lot of kick at 130 MPH, as just one example, but on the WTA I don't think anyone gets close to Stosur's kick. That's a primary reason WTA players do far worse defending their second serves than ATP players do IMHO i.e. it's extremely difficult to attack del Potro's second serve at 85 mph.

Stosur's downside seems to be predictability and variety.
.

The ratio is
the velocity of the ball divided by the number of rotations per sec

[gzhpcu]

Rod Cross wrote a recent article on the physics of the kick serve with some interesting points: http://twu.tennis-warehouse.com/lear.../kickserve.php

[jimlosaltos]

120 mph not enough?

Study Carsten Ball...his ranking won't get him into these archives...most likely...but since when does ranking have anything to do with mechanics?

Stosur's kick is flawed. Doesn't have enough velocity to spin ratio to be considered the best in tennis. I can see how old school thinkers would latch onto Stosur's kick as being so awesome.

Her right shoulder is not torqued and involved enough...this thread could lead people to think that she is flawless...when she is not...so people go out and try to teach what she does.

I'm not remotely an expert, but with Stosur's serve clocked at up to 120 mph, and typically 110-115 mph, I don't know what ratio you're seeking. Now "in tennis" is tough. Ryan Harrison has a lot of kick at 130 MPH, as just one example, but on the WTA I don't think anyone gets close to Stosur's kick. That's a primary reason WTA players do far worse defending their second serves than ATP players do IMHO i.e. it's extremely difficult to attack del Potro's second serve at 85 mph.

Stosur's downside seems to be predictability and variety.
.

[bottle]

Nice. I noticed in watching video of Dougherty's student Naomi Totka that she finishes even higher than opposite hip. And I do think her signature "sick kick" is powerful yet totally relaxed, spin-loaded and no depth with very sharp angle all on purpose. I saw Michael Llodra, another lefty, do the same thing with great effect in Winston-Salem.

[stroke]

I think John said something very significant when he described Stosar's serve as a very physical event. It certainly is not a relaxed motion, and I think this leads to the rather abrupt finish on the right side of her body. Pat Dougherty stated once when you serve the way he teaches the serve, "the harder you try, the worse you get. The motion he teaches is a very efficient way to serve". I'm not sure this is true in Stosar's case because I do think she has the best serve in women's tennis, but it certainly is physical.

Federer, Sampras, and Raonic, who all have beautiful serves to watch, all have what appears to be a very relaxed motions. When you watch Federer, particularly when he warms up his serve, you really notice how relaxed he is. Same particularly for Sampras, maybe even more so if possible. And all those guys finish their serve motion in a relaxed, balanced way, hand toward the left hip finish.

I think the same principle applies to Federer's forehand vs Nadal. Federer has a very relaxed, efficient forehand and tends to finish relaxed on the left side of his body. Nadal has a very physical, not relaxed forehand, and finishes in a very different way. A lot more physical effort appears to go into his forehand vs Federer's. This does not mean Nadal's forehand could be better if he relaxed more. Clearly, it is a brutal weapon.

I just think the relaxed motions are much more efficient and to quote a phrase used by an announcer on the Tennis Channel, "more pleasing to the eye".

Nope...Carsten Ball is far better

Study Carsten Ball...his ranking won't get him into these archives...most likely...but since when does ranking have anything to do with mechanics?

Stosur's kick is flawed. Doesn't have enough velocity to spin ratio to be considered the best in tennis. I can see how old school thinkers would latch onto Stosur's kick as being so awesome.

Her right shoulder is not torqued and involved enough...this thread could lead people to think that she is flawless...when she is not...so people go out and try to teach what she does.

[blake_b]

It seems to me that Stosur's toss is further to her left than the toss that most pros use for their kick serves. From a front view, it looks like the contact point is to the left of her head.

[DougEng]

Kick Serve Description

Doug:
Why do you think there will be less emphasis on pronation? I'm inclined to agree, since with ideal mechanics pronation is a result, not an action. But I don't have a teaching idea on that one way or the other.

"Hitting up" seems a misnomer to me. Most certainly the vector of the ball off the strings is horizontal at best, likely down slightly. I suppose it feels like you're hitting "up". But I doubt it at point of contact.

For Doug and anyone: Stosur can't hide her kick at all. Sampras did masterfully. How did Sampras (and Fed to some degree) use the same toss and starting motion to also generate a kick vs. radical ball toss and body position?

Lastly, do any of you guys have a simple verbal way to teach and describe how to hit a kicker that's an improvement over the typical?

Thanks --

That's worth an article. Yes, it can be articulated but maybe sometime later if I have time.

[DougEng]

Doug:
Why do you think there will be less emphasis on pronation? I'm inclined to agree, since with ideal mechanics pronation is a result, not an action. But I don't have a teaching idea on that one way or the other.

"Hitting up" seems a misnomer to me. Most certainly the vector of the ball off the strings is horizontal at best, likely down slightly. I suppose it feels like you're hitting "up". But I doubt it at point of contact.

For Doug and anyone: Stosur can't hide her kick at all. Sampras did masterfully. How did Sampras (and Fed to some degree) use the same toss and starting motion to also generate a kick vs. radical ball toss and body position?

Lastly, do any of you guys have a simple verbal way to teach and describe how to hit a kicker that's an improvement over the typical?

Thanks --

Sorry for any miscommunication. I meant the catch word in the next few years probably won't be "pronation" anymore. Separating pronation from other power-producing kinetic chain links isn't ideal. The correct terminology is "long axial rotation" which combines internal shoulder rotation, elbow extension, pronation, wrist flexion and deviation. Biomechanists and sport scientists are using this alternative terminology. But old habits are hard to die.

Here's an article by Bruce Elliott (top Australian biomechanist)

http://www.ncbi.nlm.nih.gov/pubmed/10824641

http://w4.ub.uni-konstanz.de/cpa/article/viewFile/2695/2533

And the USTA white paper on injuries (see page 12):

http://assets.usta.com/assets/1/USTA_Import/USTA/dps/doc_437_102.pdf

Hitting upwards is really a reference from driving off the back leg and using ground forces. The racquet drops from the power position ("trophy position") to the launch position (racquet butt points upwards to the sky and ball) as the legs straighten and come off the ground. The actual contact point is upwards and then forward/through the ball tangentially to the path of the ball.

Sampras didn't have the "same toss" all the time. If you analyze his serve, the toss actually varies but less than the typical pro. What Sampras did extremely well was hit any direction off any toss.

Yes, I have a simple way of teaching the kick serve and I can get 3.5 players to do it almost right away. It's best to feel what's happening so not truly verbalizing.

[ravirama]

Minimal back arch

What I like about her serve is the absence of a pronounced arching of the back. I wonder what she does to compensate for that and still get a good kick ?

[stotty]

Doug:
Why do you think there will be less emphasis on pronation? I'm inclined to agree, since with ideal mechanics pronation is a result, not an action. But I don't have a teaching idea on that one way or the other.

"Hitting up" seems a misnomer to me. Most certainly the vector of the ball off the strings is horizontal at best, likely down slightly. I suppose it feels like you're hitting "up". But I doubt it at point of contact.

For Doug and anyone: Stosur can't hide her kick at all. Sampras did masterfully. How did Sampras (and Fed to some degree) use the same toss and starting motion to also generate a kick vs. radical ball toss and body position?

Lastly, do any of you guys have a simple verbal way to teach and describe how to hit a kicker that's an improvement over the typical?

Thanks --

How is it possible to hit a kick serve without "hitting up". The ball would have leave the racket strings going, however briefly, "up"...wouldn't it? Can someone clear this question up.

[Smokey]

Kick

Doug:
Why do you think there will be less emphasis on pronation? I'm inclined to agree, since with ideal mechanics pronation is a result, not an action. But I don't have a teaching idea on that one way or the other.

"Hitting up" seems a misnomer to me. Most certainly the vector of the ball off the strings is horizontal at best, likely down slightly. I suppose it feels like you're hitting "up". But I doubt it at point of contact.

For Doug and anyone: Stosur can't hide her kick at all. Sampras did masterfully. How did Sampras (and Fed to some degree) use the same toss and starting motion to also generate a kick vs. radical ball toss and body position?

Lastly, do any of you guys have a simple verbal way to teach and describe how to hit a kicker that's an improvement over the typical?

Thanks --