My Take on
Aryna Sabalenka's Serve
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.