All score challenges must be made before the return of serve.

4.K. Wrong Score Called. If the wrong score is called, the referee or any player may stop play before the return of serve to correct the score. The rally shall be replayed with the correct score called.

4.K.1. After the return of serve, a player who stops play to identify or ask for a score correction will have committed a fault and shall lose the rally. A player who stops play after the serve to identify or ask for a score correction when the score was correctly called will have committed a fault and shall lose the rally.

4.K.2. After the return of serve, play shall continue to the end of the rally and the score correction made before the next serve. After the return of serve, a player who challenges the score will have committed a fault and shall lose the rally.

4.K. Wrong Score Called. If the wrong score is called, the referee or any player may stop play before the return of serve to correct the score. The rally shall be replayed with the correct score called. After the return of serve, play shall continue to the end of the rally and the score correction made before the next serve. After the return of serve, a player who stops play to identify or ask for a score correction will have committed a fault and shall lose the rally. A player who stops play after the serve to identify or ask for a score correction when the score was correctly called will have committed a fault and shall lose the rally.

After returning the serve, a savvy receiving team can question the score or player position with the intention of causing the serving team to stop play.

The referee has called the correct score. The server serves and just after returning the ball the receiver raises his paddle and says, "What's the score?". The server stops play. The referee faults the serving team for stopping play. According to 4.C.2. all "not ready" signals or questions are ignored by the referee. Since the question arose before the serving team was about to return the ball the question cannot be considered a "distraction." This rule change would eliminate the possibility of a receiving team intentionally causing the serving team to commit a fault by stopping play.