My son is a HS freshman, playing JV, who just turned 15. He's a late bloomer who is only around 5'6" and 140 pounds. Because of this, he has below average velocity for the competition. and his fastball is around 70 mph. He is mainly an infielder, but he is used occasionally on both his high school JV and travel team as a pitcher. He can throw strikes, and throws a very good spike/knuckle curve, that gets a lot of swing and miss. HIs fastball, on the other hand, gets hit a lot.
He is growing rapidly now, and his fastball should tick up a good bit in velocity as he grows. But for now, I'd like for him to add a 3rd pitch. Right now, in order to be effective, he's throwing curveball the vast majority of the time.
Would cutter be a good option for a kid who really has a good feel for a curveball? Not sure what else might work. His changeup has never really been very good or effective.
I think he can be an effective HS pitcher, and he likes to pitch, so trying to set him up to be as successful as possible when his coaches call his number.