Why does a curveball curve?
The principle factor affecting a moving (and spinning) baseball is air drag. Imagine a standard fastball thrown with a straight overhead motion. The ball will be spinning naturally on a horizontal axis (with the top of the ball rotating back toward the pitcher). This spin causes the magnitude of the drag vectors to be different near the top half of the ball than they are on the bottom half. Without the spin, the drag force would be equal on both hemispheres of the ball… Read more…