Ace (tennis)
An ace in tennis means a single-stroke point won by the server who produces a service that his opponent cannot reach with his racket and thus fails to return. By definition, an ace will NOT occur should the opponent touch the ball in any way, even if the return is illegal.
In professional tennis, aces are generally seen on a player's first serve, where the server can put maximum effort on power and take more chances with acute placement (usually the corners of the service courts and the centre serviceline).
The fastest recorded ace in tennis history has been served by the American Andy Roddick.
The ATP circuit record for most aces served in one match is held jointly by Joachim Johansson and Ivo Karlovic (51 aces).