Caroline Wozniacki Photos: Picture Gallery of Strokes

Caroline's wrist has completed the last link in the kinetic chain, whipping upward and forward to drive the racquet up and across the back of the ball for the combination of topspin, slice (sidespin), and power that constitute a world-class first serve. The absolute full extension Caroline shows here is essential to making the kinetic chain work, and it maximizes her angle over the net.