This book shares my personal knowledge of tennis. I am an amateur player. I started late, at the age of fifty-four. Sometimes I win, sometimes I lose, but I always understand the game. It was impossible without knowledge. Years ago my frustration in skiing came to an end due to a picture that compared skiing to bicycle riding* It was all I needed for skiing technique to become natural to me and to become an advanced skier in a matter of days. The necessity to find the "bicycle" of tennis to really start playing was obvious to me. My background made it possible. Actually, it was two "bicycles" two elements that constitute a powerful tennis stroke. Once found, my game changed from end to end. Implementing these two elements in a stroke and practicing them, rather than chasing a ball, became a major part of my training. Hitting the ball became a result of a well-designed tennis stroke. Identifying and understanding elements of a tennis stroke require knowledge in physics. Sharing this knowledge in a simple language is all this book is about: illustration of two elements that constitute every powerful tennis stroke and then presenting the forehand, backhand, and service as a combination of these two. *The Anatomy of Skiing by R. J. Sanders, MD