Commonly people think a knuckle curve is related to a knuckle ball A knuckle curve is part of curveball family It’s just the way that you get your pointer finger out of the way Some guys knuckle it with their fingertip like how you throw a knuckle ball and some guy actually curled her finger all the way and have their actual knuckle on the ball. Both are correct. This can help people throw it hard harder and get more spin But everybody is different with how they’re curveball feels and what’s bes