What does knuckling a ball mean?

Answer 1

A knuckle ball is thrown when a pitcher hold the ball, not with his fingers fully extended, but bent such that only the "knuckle" of the fingers is touching the ball when released. When done right -- and it is not an easy pitch to throw correctly -- the ball will have very little spin. As such, the ball can go just about anywhere before it reaches the plate, depending on how the wind is blowing. When a good knuckleball pitcher is throwing well, batters will be flaying at the ball almost helplessly, as even the pitcher has no idea what it will do as it heads towards the catcher.