Apart from being one of the most important strokes in the game, the tennis serve is also the most complex (Girard et al., 2005).  It is unique to the game as it is the only stroke in which the player has complete control over, as it is not interfered with by their opponent. There are three main types of tennis serves; the flat serve, the slice serve and the kick serve. However, despite these slight variations, all three types of serves are extremely similar in the biomechanical principles behind them.