In table tennis, how often does service change during a game before deuce?

In table tennis, service changes every two points during a game before deuce.

The server delivers two consecutive services, after which the receiver becomes the server for two points. This alternating pattern continues until the game reaches 10–10. At that stage, service changes after every single point rather than every two points.

The rule helps prevent one player from gaining an excessive advantage from serving throughout a long sequence. It applies in singles and doubles, although doubles adds a prescribed order for which player serves to which receiver.

A common mistake is to apply the one-point-at-a-time rule throughout the entire game. That rule begins only at deuce, the score of 10–10. A game is won by the first player or pair to reach 11 points while leading by at least two points, so extended games can involve many rapid service changes.