The investigation was instigated by a growing concern from the International Tennis Federation (ITF) that the contribution of racket technology in the modem game of tennis might be changing the nature of the game by making it too fast. The serve was earmarked as the most critical stroke influencing the speed of the game, resulting in the decision to build a test machine, which would investigate racket performance under realistic serve conditions. In order to determine the design specifications for the machine the following studies were performed.