I am new to the forum, but would appreciate any help you all can offer. I have a son (15) who is pitching for his High School team. He is a lefty, and is having trouble with control. He either misses low and inside on a righty or high and outside on a righty. I am wondering if there is something we can try, or if his mechanics are causing this?
Throwing strikes is all mechanics. So you’re right about that.
On the low and inside pitch to a righty, your son might be 1) rotating too much, which is causing his release point to be farther in front of his body, or 2) holding on to the baseball too long, which, again, is causing his release point to be too far in front of his body.
On the high-outside pitch, he’s not rotating the hips enough and/or leading the release of the pitch with his wrist and not his finger tips.
Positive repetition is how to change control issues: throwing practice bullpens off of a mound, throwing on the side, etc. It’s a feel thing, so repition is key here. (Video taping is also an excellent way to develop better pitching mechanics – which, of course, leads to better control.)