USTA Comment 3.1: May a player cause a ball to become wet by using the ball to wipe perspiration from the player’s body? No. A player may not take any action that materially changes the condition of the ball; therefore, a player may not use a ball to wipe off perspiration.
The Racket
Case 3: Can vibration damping devices be placed on the strings of a racket? If so, where can they be placed?
Decision: Yes, but these devices may only be placed outside the pattern of the crossed strings
Ball Touches a Pernament Fixture
USTA Comment 13.1: What happens if a ball hits an object attached to the net or post (such as a scoring device) or the top of the net outside the singles stick and then lands in the court? The player who hit the ball loses the point because it hit a permanent fixture before landing in the court.
Service Fault
Case 1: After tossing a ball to serve, the server decides not to hit it and catches it instead. Is this a fault?
Decision: No. A player, who tosses the ball and then decides not to hit it, is allowed to catch the ball with the hand or the racket, or to let the ball bounce.
When to Server and Receive
The server shall not serve until the receiver is ready. However, the receiver shall play to the reasonable pace of the server and shall be ready to receive within a reasonable time of the server being ready. A receiver who attempts to return the service shall be considered as being ready. If it is demonstrated that the receiver is not ready, the service cannot be called a fault.
The Let During a Serve
The service is a let if:
a. The ball served touches the net, strap or band, and is otherwise good; or, after touching the net, strap or band, touches the receiver or the receiver’s partner or anything they wear or carry before hitting the ground; or
b. The ball is served when the receiver is not ready
The Let
Case 1: When the ball is in play, another ball rolls onto court. A let is called. The server had previously served a fault. Is the server now entitled to a first service or second service?
Decision: First service. The whole point must be replayed.
Player Losses Point
The point is lost if:
g. The player or the racket, whether in the player's hand or not, or anything which the player is wearing or carrying touches the net, net posts/singles sticks, cord or metal cable, strap or band, or the opponent's court at any time while the ball is in play; or
h. The player hits the ball before it has passed the net; or
i. The ball in play touches the player or anything that the player is wearing or carrying, except the racket; or
j. The ball in play touches the racket when the player is not holding it; or
Case 7. A ball that has just been served hits the receiver or in doubles the receiver's partner before it touches the ground. Which player wins the point?
Decision. The server wins the point, unless it is a service let
A Good Return
Case 2: A ball in play hits another ball which is lying in the correct court. What is the correct decision?
Decision: Play continues. However, if it is not clear that the actual ball in play has been returned, a let should be called.
Hindrance
If a player is hindered in playing the point by a deliberate act of the opponent(s), the player shall win the point.
However, the point shall be replayed if a player is hindered in playing the point by either an unintentional act of the opponent(s), or something outside the player's own control (not including a permanent fixture).
Case 3: A ball in play hits a bird flying over the court. Is this a hindrance?