Here we see one of the big three secrets of pro strokes. Watch how Acasuso's hand and shoulder work together to lift the ball. The straight arm, perfectly supported by the shoulder, provides a lot of mass and leverage through contact. You should feel your shoulder and and hand working the ball on every stroke.

A second element to notice is the gradual turning of the hand. The knuckles of Acasuso's hand, which face the net on contact, end up facing the right fence. This gradual and steady turn of the hand helps impart topspin on the ball.