LONDON (AP) Once deemed the ''next big thing'' in tennis, 2009 U.S. Open champion Juan Martin del Potro grew so frustrated after needing three operations on his left wrist that he considered quitting ...

If you have trouble snapping your wrist to create spin on your serve, you might be gripping your racquet too tightly. To serve effectively, you must relax your hand and keep your arm loose. Serving ...