What are some effective drills/ways to help high school pitchers bring the ball down?
Mechanical issues like inappropriate postural shifts or timing issues such as early shoulder rotation can pull the release point back and raise it up. That will make it difficult to keep the ball down.
So, work on keeping posture stable through ball release and manage the glove side to buy the timing to keep the shoulders closed and rotate late.
Roger brought up an important point here: watch your release point. If you release the ball too soon, your pitch is likely to be low, and if you release the ball too late the pitch is likely to be high. So what you want to do is keep an eye on the release point and make sure that you get it to the point where the pitch is where you want it to go. Another thing: I have no idea what your arm slot is, but if you throw 3/4 or sidearm you will probably have greater success in keeping the ball down in the strike zone. 8)
roger what do you mean by manage the glove side to by the timing?
I always drill into the minds of my high school pitchers to finish with their chest over their front knee, if you can prevent them from finishing standing straight up you can help eliminate the tendency of high pitches
Don’t drop the glove, don’t pull it, and don’t fly open with it. Extend the glove out front with arms in an “equal and opposite” position, stabilize the glove out front, and bring the chest towards the glove. If you do this, you will likely buy yourself the timing to keep the shoulder closed longer and rotate later.