This article will show you how to grip a 4-seam fastball, a 2-seam fastball, a cut fastball (cutter), and a split finger fastball (splitter), as well as offer tips on how to throw them. 1. Pick up baseball and place in throwing hand. 2. Hold the ball with a proper throwing grip. This means your index finger and middle finger are on top of the ball with your thumb pushing it against your folded ring finger and pinky for support. 3. Rotate the ball in your hand until you find the “horseshoe seam”.