Abstract: In some sports it is difficult for a coach to instruct his player during a game or match. For example, the coach may be out of earshot from the player. In tennis, the rules for elite amateur and professional matches prohibit a coach from instructing a player during a match. This is problematic because a player, especially a young player, can be easily distracted from his or her game or strategy. It would be desirable to be able to remind the player of certain desired aspects of his game or to provide words of encouragement when needed in real time during the match to direct the player back to a game-winning strategy.