Hanging or spinning curve

Have him try to shorten his stride slightly when throwing a CB, focus on getting on top of the ball, and think about driving his fingers into the ground. He is most likely starting to throw more of a slider and getting on the side of the ball, and coming out through more toward the batter. Usually an easy fix. A spiked curve grip tends to force your hand up on top of the ball if he wants to mess around with grips some.

I think you answered your own question. He can throw a curve, just not the same way every time. So, have him walk through each step and tell you what he does and why. Consider grip (2S, 4S, ??), arm slot (3/4, sidearm, high), stride (long, short), start position (stretch, windup), release (pronate, supinate), etc.

ExWrangler,

Postural issues and timing issues (i.e. opening up early) will pull the release point back and raise it up. That will do two things: (1) launch your pitch on an up-and-in trajectory and (2) make it difficult to get over the top of the ball to spin it.

Look for posture changes during the delivery including tilting to the glove side. Also look at what the glove arm does. If it flies open, drops or pulls back then the result will likely be early shoulder rotation.

A release point that is further out in front will get more movement.

Has he went through any kind of growth spurt? He could be just out of whack with his body. The stuff above is pretty good but it might be as simple as he's got to relearn his body.

My son does this as well. Have him remember to finish his pitch and have his arm continue downward after release to the outside of the left knee (if a RHP). Also, tell him to remember to keep his thumb up at release like a "karate chop". The grip on the ball needs to be a two seem grip with the index and middle finger basically touching each other up against the RH seam. Let it fly and it should spin with both a vertical and horizontal drop...

My son always had a late breaking, tight spinning breaking ball....... As long as "he thought fast ball" when throwing it. I.E., same slot, arm speed and late release out front, it was virtually untouchable.

When he was off, caused by all the physical flaws mentioned earlier; stride too long, flying open, trying to impart spin, etc; all he needed was that mental cue, "think fastball" and he was right back where he needed to be.

What works for one may not work for another but always felt it was important to stay on top and release out front, just as you do with your heater.., if you want a non-"humper" that the hitters sees early because it just spins up there.

Great points Roger Tomas and not just because of the name.

My son has the same problem. With him it is that he throws 3/4 and will drop his elbow causing the ball not to break and hit the batter. I always tell him to go threw each step of throwing in his head before he throws a pitch, especially to keep his elbow up.

throwing like a fastball is number one... number two try the knuckle curve grip. It should impart the ability to throw harder with tighter spin. This was the case with my son. ymmv of course

Here's a youtube on How to keep from hanging your curveball that I just came across.