A major league pitcher's curveball can break over 17 inches, and you thought trying to hit your dad’s underhand slow pitch was hard. Curveballs are one of the most unorthodox pitches in baseball, but they can really mess with the mind of a batter. Over the course of a pitch, the deflection of the ball from a straight line increases as the ball gets further away from the pitcher. Overall, that deflection can be greater than 17 inches. On top of that, the ball can break towards either first or third base, depending on which way the ball is spinning.