where does the tennis ball have to land on a serve
Serve (tennis) A serve (or, more formally, a service) in tennis is a shot to start a point. A player will hit the ball with a racquet so it will fall into the diagonally opposite service box without being stopped by the net. Normally players begin a serve by tossing the ball into the air and hitting it (usually near the highest point of the toss). The ball can only touch the net on a return and will be considered good if it falls on the opposite side. If the ball contacts the net on the serve but then proceeds to the proper service box, it is called a let; this is not a legal serve in the major tours (but see below) although it is also not a fault. Players typically serve overhead, but serving underhand, although rare, is allowed. The serve is the only shot a player can take their time to set up instead of having to react to an opponent's shot. But as of 2012, there is a 25-second limit to be allowed between points.[1]
Tennis A recent rule change is to allow coaching on court on a limited basis during a match.[60][61][62][63] This has been introduced in women's tennis for WTA Tour events in 2009 and allows the player to request her coach once per set.[64]