My 7-year-old son played in his first QuickStart tournament today. He did great! He had a great attitude, played hard in all his matches, despite losing 8-1 (pro set) in his first match, he was very polite, friendly and eager to play again later in the day. In one of his later matches, I noticed that a few serves were maybe six inches over the service line and thus, a fault. However, he was hitting them back and playing it. The other player would sometimes be confused and then quit playing, then losing the point! (kind of funny to watch) He explained to me later that he thinks winning points on double faults was boring and that he enjoys actually hitting the ball. My understanding is that every shot that lands on his side of the court is his call. He is honor-bound to make a call with integrity and honesty. But if he is calling bad serves good (to his opponent's benefit) in order to get more on-court action, is that technically legal? What does the rule book say on this?