Rule Number 10
Service Fault
The Service is a fault:
(a) If the Server commits any breach of Rules 7, 8 or 9(b);
(b) If he misses the ball in attempting to strike it;
(c) If the ball served touches a permanent fixture (other than the net, strap or band) before it hits the ground.
Case 1. After throwing a ball up preparatory to serving the Server decides not to strike at it and catches it instead. Is it a fault?
Decision. No.
[USTA Comment: As long as the Server makes no attempt to strike the ball it is immaterial whether he catches it in his hand or on his racket or lets it drop to the ground.]
Case 2. In serving in a singles game played on a Doubles Court with doubles posts and singles sticks the ball hits a singles stick and then hits the ground within the lines of the correct Service Court. Is this a fault or a let?
Decision. In serving it is a fault because the singles stick the doubles post and that portion of the net or band between them are permanent fixtures. (Rules 2 and 10 and note to Rule 24.).
[USTA Comment: The significant point governing Case 2 is that the part of the net and band outside the singles sticks is not part of the net over which this singles match is being played. Thus such a serve is a fault under the provisions of Article (c) above . . . By the same token this would be a fault also if it were a singles game played with permanent posts in the singles position. See Case 1 under Rule 24 for difference between “service” and “good return” with respect to a ball’s hitting a net post.]