do forearm exersizes and practice snapping your wrist
You don't snap a curve-ball.
I was taught that it's more like the motion you do when you crank the key on your car.. Faster..
EDIT I was adding on to the above guys post, I don't recommend any kind of key turning workout involving your car
You can snap off a curveball by pronating instead of supinating. But in order to pronate while releasing a curveball you need to have as much supination as Barry Zito has in the photo below. This is how Dr. Mike Marshall teaches his curveball release. Most pitchers don't supinate as much as Zito does on their curveballs, though.
xv do you have continuence pictures, I've always been curious of the "pronated curve" that the Marshallites have always touted and what Zito has going is what appears to me as early supination, how does he get his hand all the way over on top to a pronated position?
He shouldn't be throwing a curve or screwball at his age (11)