2. When a player chooses to serve first or receive first or choose a court, another player should have another choice.
3. After each score, the receiver becomes the server, and so on, until the end of the game, or until the scores of both sides reach 10, the order of serving and receiving remains unchanged, and each person only serves one point in turn.
4. The party in one direction in a certain game should be changed to another direction in the next game. In the singles deciding game, when one side scores 5 points, it is necessary to change places.