Looking at the bigger picture (no pun intended), we are talking about an age for curve balls. Consider this, in high school, I see way too many kids with rotator cuff and elbow problems. Not from curves, but from things like 1)improper or no warm up, 2)poor pitching form (from throwing too hard), and 3) too many pitches. I'm talking about the top 10%, the ones that might play at the next level, but are the ones getting the raw end of the deal, just to win for their Coach, dad, or themselves. Nobody want to hurt these kids, but it happens. There is not an easy solution to correct this other than education.