What is an ace in tennis?
An ace has to be a good serve: it lands in the correct service box and the receiver fails to get a racquet on it. If the receiver touches the ball but can't return it into the court, statisticians call it a service winner instead.
Aces come most often from first serves hit flat and wide or down the T, and on fast courts where the ball skids. A serve that clips the net and lands in is a let, not an ace, and is replayed.
In a match
At 30–30 the server hits a flat first serve down the T and the returner doesn't move: that's an ace, 40–30.
Questions
Is a serve the receiver touches an ace?
No. If the receiver gets a racquet on it, it's a service winner, even if the return doesn't come back.
Does a let serve count as an ace?
No. A serve that touches the net and lands in the correct box is a let and is replayed.
Sources
- ITF Rules of Tennis