When I was umpiring college baseball at one of our yearly clinics we had Dr Andrews come and speak. I wish every parent who had a child that plays baseball could have heard his lecture. He said that he sees more damaged elbows from kids who throw way too much. He said that it's ok to teach a kid to throw a curve ball, but would not recommend letting him throw it on a consistent basis, in games or practice till they were at least 16-17 years old. He said 90% of rec league and travel ball coaches over throw pitchers and don't know how to care for their arms after they are taken out of games and the following day. If anyone ever gets the chance to hear him speak, please do so. There is not a more qualified person when it comes to shoulders and elbows.