The fastball is the most common type of pitch thrown by pitchers in baseball and softball. Its distinctive feature is its high speed. "Power pitchers," such as former American major leaguers Nolan Ryan and Roger Clemens, rely the speed of the fastball to prevent the ball from being hit and throw fastballs at speeds of 95–105 miles per hour (153–169 km/h) (officially) and up to 108.1 miles per hour (174.0 km/h) (unofficially). As an alternative to the fastball, pitchers can put movement on slower thrown balls, or throw them towards the inside or outside of home plate where batters cannot easily reach it.

In baseball, the pitcher is the player who throws ("pitches") the baseball from the pitcher's mound toward the catcher to begin each play, with the goal of retiring a batter, who attempts to either make contact with the pitched ball or draw a walk. In the numbering system used to record defensive plays, the pitcher is assigned the number 1. The pitcher is often considered the most important player on the defensive side of the game, and as such is situated at the right end of the defensive spectrum. There are many different types of pitchers, such as the starting pitcher, relief pitcher, middle reliever, lefty specialist, setup man, and the closer.