Analyzed by John Yandell
Andrei Rublev can rocket groundstrokes with anyone. His first serve, while not at the high end of pro velocities, can be a weapon. But compared to most elite pro players, his second serve can be a liability, causing him lost points, double faults, and, at times, obvious frustration.
His second serve ball speed can be in the low 90s or high 80s but sometimes drops in the 70s or even high 60s. There are many women servers with higher second serve mphs.
Why is that? If we look at Andre's service motion in high speed video, we see he has a great, flexible shoulder. His internal shoulder rotation and the rotation of his arm and racket in the upward motion–so called pronation--is equal to the best servers.
But Andre has technical problems with his stance and the movement of his feet during the motion. These stem from his extreme pinpoint stance in which he drags his back foot up and then around his front foot.