In volleyball what is an ace?

Answer 1

Any time the receiving team does not have "two controlled touches" on the ball, and does not get it back over the net, an ace is awarded.

Example: The receiver misses the ball completely. Ace.

Example: The receiver makes contact, but shanks the pass out of bounds. Ace.

Example: The receiver shanks the pass into the back of the middle's head. Not a controlled second touch. Ace.

Example: The receiver makes a beautiful pass, but the setter forgets to set it and the ball hits the floor. While naively you might not consider this an ace because of the good pass, technically it is an ace indeed because there was no second controlled touch.

Example: The serve hits the receiver in the head but somehow bounces over the net into the serving team's court. Despite the lack of "controlled touch" by the receiving team, the ball was kept in play so obviously not an ace.

Answer 2

an ace is when your team serves it over and the opponets didn't touch the ball at, but it was in.