I realize this may a be a bit off topic, but not so if you are playing in an an adult league with Michael Chang. I have some absolute beginners (think no sport experience AT ALL) who will have to play some matches SOON. There are about 5 out of the 7 who cannot throw the ball up in the air and patty cake it over the net into the correct service box 3 out of 7 times. I am working desperately with them on that, but I am also helping teach basic forehand and backhand as well. In a desperation move, I'm thinking of having them serve underhand their first few matches. Almost all of them can bounce hit a forehand into the right service box more than 50% of the time. My Question - is it legal for them to "bounce hit"? Or must they release the ball into the air from their hand and hit it before it bounces?