The former US Open champion has an amazing kick serve. Stosur hits one of the heaviest balls on tour—high velocity combined with incredible topspin, on both her first and second deliveries. The key to the Australian’s awesome serve is the often-misunderstood concept of racquet tilt at contact.


Stosur turns her shoulders away from the net during her windup, allowing them to rotate back into the ball. She also gets a great push from her back leg, which stays behind her instead of coming up near the front foot.


During the swing, Stosur rotates her arm and racquet 180 degrees out into the follow-through, so the frame is on edge or perpendicular to the court. This motion is often described as pronation, and is an indication of racquet-head speed.


Many believe the racquet tip should point straight up to generate topspin, but it must tilt to the player’s left. This allows Stosur to make contact while the racquet face is still moving upward.


On Stosur’s first serve, the tilt is about 30 degrees to her left. On her second serve, it can approach 45 degrees. Stosur tosses farther to her left so her contact point is between her shoulder and the right side of her head.

John Yandell is the publisher of the digital magazine and an instruction editor for TENNIS.