I have my son, 9yrs, doing Oly lifting w/ a coach. They train the Clean and Jerk and the Snatch. They train accessory lifts like high pulls, rack jerks, front and back squats as well. They also do box jumps and various other Plyo drills. If form is solid then adding minimal weight is ok. At 14, depending on where his test production is...(at 14 I didn't have a hair on me) he may be able to be more aggressive about adding weight.
Some Natl Champ level High School baseball teams are now doing Oly style training (not to mention college, especially off season), as are the football teams. The training creates explosive power, which is very dynamic compared to what is accomplished lying on a bench pressing weight or pulling weight off the floor up to your knees. While good lifts, the bench and deadlift are childs play compared to the Clean and Jerk and Snatch. The auxilary lifts are all harder - form wise and all very taxing.
Not baging the Holy 3, as I train them all, but when in Baseball are you lying flat on your back? Sports are dynamic. Increased speed, power, and quickness are all direct benefits of Oly training. Throw in some plyos and some kettlebell work (a good oly program would have these IMO) and your son will be a machine. He will also gain tremendous strength in his RC's and his entire shoulder girdle (snatch). Flexibilty will improve (oly squats are as real as it gets, people say 'atf' alot, but their butt has never touched the ground w/ weight on thier back...his will, and his legs will be powerful). Speed on the bases, home to first, first to second... he will be able to take biger leads... List really goes on.