CADad, It sounds like you're doing a great job with your son and congrats on his success. My son is 15 and just finished his freshmen year. He is playing with the varsity a couple of days a week and with a top 15U team Thursday-Sunday. We didn't let him throw a curve until really last summer. As a result, he has a nice changeup which is still a more effective pitch. Good luck with your team as the summer goes on.