There is a 6 ft. LHP that is 13 years old, tops out at about 70. His delivery is around 3/4 (closer to sidearm, sometimes drops down to sidearm) but even when he tries to throw over the top with his curveball, he still gets side movement, now don’t get me wrong, the curveball still drops a lot, but it also moves quite a lot to the right too. His primary pitch is a two seam, and that moves a lot, too. His curveball grip is just like a two seam, accept he moves his index finger right up against his middle finger. Any thoughts?
He hits too much of the side of the ball when he releases it. Releasing it further out in front of him should do the trick so that it leaves his hand almost on the same plane as his fastball.
Probably a wrist-angle issue. If you think of the ball like a box, he’s pulling down on the top left corner (cuz lefty) instead of just the top. I sucked at explaining that. Bleh.
Movement has a bit to do with arm slot. Some curves move a bit away toward the extension side. If you change release point so ot no longer matches your fastball, it will be easier for batters to spot your curve. When working on getting to the front of the ball, just be aware of that.