A four-seam fastball has the most velocity of all types of fastballs, but usually has the least movement. It is the most basic pitch in every arsenal and the foundation of every pitcher’s success.
Normally, pitchers place their index finger and middle finger across the seams — where the Rawlings sign is located; i.e. the horseshoe — with medium to light grip pressure. The distance between the fingers should fall naturally. The thumb should rest between those two fingers with a clinched ring, and the pinky finger should be rested right on the ball with as little pressure as possible.
Ideally, the amount of pressure should rest entirely on the fingertips and pitchers should be able to tuck a few fingers between the ball and their palm. Four-seamers are intended for minimum friction; the decreased friction means less drag and induced spin, which increases the speed out of the hand.