Stolen base

In baseball, a stolen base occurs when a runner advances to a base unaided by other actions and the official scorer rules that the advance should be credited to the action of the runner. The umpires determine whether the runner is safe or out at the next base, but the official scorer rules on the question of credit or blame for the advance under Rule 10 (Rules of Scoring) of the MLB's Official Rules.

A stolen base most often occurs when a base runner advances to the next base while the pitcher is pitching the ball to home plate.

Background

Ned Cuthbert, playing for the Philadelphia Keystones in either 1863 or 1865, was the first player to steal a base in a baseball game, although the term stolen base was not used until 1870. For a time in the 19th century, stolen bases were credited when a baserunner reached an extra base on a base hit from another player. For example, if a runner on first base reached third base on a single, it counted as a steal. In 1887, Hugh Nicol set a still-standing Major League record with 138 stolen bases, many of which would not have counted under modern rules. Modern steal rules were fully implemented in 1898.

Base stealing was popular in the game's early decades, with speedsters such as Ty Cobb and Clyde Milan stealing nearly 100 bases in a season. But the tactic fell into relative disuse after Babe Ruth introduced the era of the home run – in 1955, for example, no one in baseball stole more than 25 bases, and Dom DiMaggio won the AL stolen base title in 1950 with just 15.