Side arm pitch

I have a 10 yr old that pitches side arm and flicks his wrist to the side when he releases the ball how do we break that habit?

Have him try to keep a stiff arm, Kinda imagine your forearm as a board. Some pitches sidearm need a small flick like curveballs and breaking pitches, but it could be problematic and probably slowing down fast balls (Which are money at that age). Good luck!

Let me add, it depends on the degree of the flick. I mean it could just be natural, when i pitch my wrist is really flexible. Just make sure his arm/hand is following all the way through not stopping when he releases

Right. IF what he’s doing with his wrist is natural, don’t worry about it. Just make sure he follows through, completes his pitches—and it would be a good idea for him to learn to use the crossfire. This is a beautiful and absolutely lethal move that works only with the sidearm delivery and that will work with any pitch. I picked up on that when I was 13—I was a natural sidearmer all the way—and a few years later my wise and wonderful pitching coach helped me refine it, as well as showing me how to throw a good slider and teaching me all sorts of very advanced stuff he felt I needed to know. 8)