This tennis stroke analysis, based on the application of biomechanic principles, is designed to help those who play tennis only once or twice a week. It is noted that, because the tennis player has a limited power potential, the only way to increase his racket head speed is to rotate his body. The mechanics of tennis are discussed by dividing it into: (1) ground strokes; (2) footwork; and (3) forehand and backhand. The section about ground strokes talks about how to stand, how to hold the racket arm, and how to distribute body weight; the stroke is subdivided into the step, the rotation, and the swing. The section on footwork discusses (with illustrations) the position of feet on the court, four different types of step selection, the follow through, and the defensive position. The section on forehand and backhand strokes describes both processes, and the proper grip for each. Throughout the paper, specific application of biomechanic principles is made to help the tennis player who plays occasionally to improve his or her game. (JM)