Pat Dougherty is a stroke and movement specialist who has written and produced more than two-dozen tennis instructional videos including "Sonic Serve" and "Killer Forehand." He patented the A.P. Belt Training System, a breakthrough athletic development program for tennis players used by many top NCAA teams. Pat is based at the Bollettieri Tennis Academy, where he is also known as the "Serve Doctor." To find out more about Pat Dougherty, go to his website AP Belt Training System.