My Take on
Aryna Sabalenka's Serve

ohn Yandell

I love the fact that the Forum discussion of Aryna Sabalenko's serve is over 1000 views and has 90 or so comments from multiple subscribers.

And it's great to hear all the thoughts about what is "wrong" with her motion. As Jim Fawcette noted when he put up the video, these theories are wide ranging, from there is no biomechanical problem. To it's all mental.

To it's her stance. To it's the hand and racket path at the start of the motion. To it's her toss. To it's the position of her opposite arm. To it's the obvious hitch in her backswing.

Where to Start?

The question is—hypothetically—which is it and where would a coach start to try and help her?

Jim also suggested that a major problem is the lack of "long axis rotation," also known as internal shoulder rotation. That's what I think too.

And if I was that hypothetical coach, that's where I would start.

Doesn't mean that some of the other technical points aren't valid, but there are plenty of top players that have those various issues and still serve way more consistently than Aryna.

Internal Shoulder Rotation

So what doesn't that mean—internal shoulder rotation? This is the hand, arm, and racket rotation from the racket drop position to the contact, then to the extension, which is the point just before the racket starts to come back across the body to the player's left.

For most of the great servers this rotation is about 90 degrees from the drop to the contact, and then another 90 degrees out to the extension. It's an indication of racket speed and that the racket maximizes acceleration up to and through the contact, the same way the extension of the followthrough is critical to racket speed on the groundstrokes.

If we look at Aryna, her serve doesn't have that. She does have a good racket drop. Between the drop and the contact, the racket rotates about 90 degrees.

But then the rotation basically stops. On a small percentage of serves, there is something like 20 degrees of additional rotation.

But on most serves the racket face is flat or parallel to the court. On some she also breaks her wrist forward. Makes me wonder if she is trying to "snap" but no way of knowing that for sure.

Spin Values

If it was up to me, I'd film her and calculate her spin values for both first and second serves. My guess is that they would be low compared to other servers.

Then I'd show her video of great servers making the continued rotation after contact. Then I would have her model this fully rotated position without the ball.

Then I would have her create a mental image of this rotated position with her eyes closed. Then I would have her, still eyes closed, model her motion from the drop to the new position.

Then it would be time for her to hit balls. I'd ask her to use the image of this new fully rotated extension position as a blue print, projecting this image in space and covering it with her actual racket.

My bet is she would gain ball speed—scary since she can already hit 120mph on the gun. But that wouldn't be the goal.

This rotation is also critical for spin. So after she was comfortable with that, I'd measure her spin values again. I'd expect then to go up.

Now what about all the other technical problems? Sometimes if you make one critical correction you see other issue magically disappear.

Only one way to find out. And again high speed video would tell the tale. What if anything would this change do to the start of her wind up? What about the elbow position?

I might ask her to model and try a more circular wind up as I did when I worked with Paul Goldstein years ago. (Click Here.)

I might ask her to modify her stance, starting with her shoulders square to the net rather than open the way she is currently serving .I might ask her to toss a little more to her left to make increasing spin easier.

Who knows? It's all hypothesis, but it would be fun to try.