Settling the Score
Sometimes two players disagree on the current score during a tennis match played without an on-court official. The correct procedure to resolve the dispute is to roll back the score until they reach agreement on the score at a previous point in the match. Play is resumed from there. In fact, if a roving official is summoned to the court that is usually how resolution is achieved. If the score was previously announced by one player without objection from the other, that is generally regarded as a point of agreement.