Knuckle curve

The knuckle curve is a breaking pitch similar to a curve-ball which is thrown with a grip similar to its namesake, the knuckleball. Its grip involves any number of fingers—usually all four or just the index finger—bent the same way as a knuckleball grip. If only the index finger is bent, the rest of the fingers grip it as a normal curveball grip. It is thrown similarly to a curveball. Its movement is less predictable, often more downward, than a curveball, but less erratic than a knuckleball.

This pitch is currently used by Major League pitcher Mike Mussina [1] (http://www.baseball-reference.com/m/mussimi01.shtml).