Situations Resulting in an Ace
The most common reason for awarding an ace is when the served ball lands in-bounds on the opponent's court and is not touched by any of the receiving players. It's also considered an ace if the ball is touched by a receiver and then passed to a teammate, who is unable to keep it in play. If the receiver mishandles the served ball, such as committing a double hit, the official will declare a service ace. An ace can also be the result of the receiving team being out of rotation, such as an overlap violation, which is when receiving players are out of position at the time the ball is served.