Canadian doubles, also known as cutthroat tennis, is a method of playing tennis with three players. It pits two players against one player on the court at the same time. The only major rule variation between Canadian doubles and traditional doubles tennis is that the team of two players can only hit the ball within the single player's singles lines, whilst the single player can hit into the full doubles court on the two player's side. Canadian doubles is used as a training method, to work on shot-making, accuracy and teamwork. It is also used when one player is significantly better than the other two.