Tennis - Rally judgment
Line calls and hindrance, point by point.
Many tennis arguments start after the rally looks finished, but the real ruling usually turns on an earlier event: the ball may already have landed out, touched the correct line, bounced twice, or become unplayable because one player hindered the other. The first decisive event controls the point.
Quick ruling: decide whether the ball was still legally in play before judging the next shot. If the point should already have ended because the ball was out or a player was hindered, later contact does not revive it.