My 13 yr old brother serve

[hyperthom007]

Hi guys, I am trying to teach my brother serve and he has managed to pick up the flat serve. However, it is not always consistent and I was thinking of teaching him how to do a top spin serve.
I was wondering if 13 years old is a little too young for this serve or otherwise? I have no idea because I did not receive proper coaching and I only picked up tennis like 2 years ago... So advices are pretty much well appreciated.
Thanks

 

[LeeD]

Topspin serve, have him toss the ball over his head, so it lands aligned with his head, instead of out to the hitting arm side.
If he needs more spin, tell him to slice it more, leading with the edge of the racket.
He HAS to clear the net my about 2-3', to get the spinning ball into the court. His topspin serve should be easily 30 mph SLOWER than his flat serve to start with, and for a second serve.
Topspin serves have to ARC in, not go straight to the opponent's service court.