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.

Successful base stealers must be fast and have good timing.

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. However, in the late 1950s and early 1960s, base-stealing returned to prominence primarily thanks to Luis Aparicio and Maury Wills, who broke Cobb's modern single-season record by stealing 104 bases in 1962. In turn, Lou Brock broke Wills’ record in 1974, as did Rickey Henderson in 1982. The stolen base remained a popular tactic through the 1980s, perhaps best exemplified by Vince Coleman and the St. Louis Cardinals, but began to decline again in the 1990s as the frequency of home runs reached record heights and the steal-friendly artificial turf ballparks began to disappear.

Base stealing is an important characteristic of the "small ball" managing style (or "manufacturing runs"). Such managers emphasize "doing the little things" (including risky running plays like base-stealing) to advance runners and score runs, often relying on pitching and defense to keep games close. The Los Angeles Dodgers of the 1960s, led by pitcher Sandy Koufax and speedy shortstop Maury Wills, were a successful example of this style. The antithesis of this is reliance on power hitting, exemplified by the Baltimore Orioles of the 1970s, who aspired to score most of their runs via home runs. Often the "small ball" model is associated with the National League, while power hitting is associated with the American League. However, some successful recent American League teams, including the 2001 Seattle Mariners, 2002 Anaheim Angels, the 2005 Chicago White Sox, and the 2015 Kansas City Royals, have excelled at "small ball." The Royals in particular embodied this style within the 2010s, leading the league in stolen bases but finishing last in home runs in 2013 and 2014, leading to a berth in two consecutive World Series, the second of which they won in 2015. Successful teams often combine both styles, with speedy runners complementing power hitters—such as the 2005 champion White Sox, who hit 200 home runs, which was fifth most in the majors, and stole 137 bases, which was fourth.

Baseball's Rule 8 (The Pitcher) specifies the pitching procedure in detail. For example, in the Set Position, the pitcher must "com[e] to a complete stop"; thereafter, "any natural motion associated with his delivery of the ball to the batter commits him to the pitch without alteration or interruption." A runner intending to "steal on the pitcher" breaks for the next base the moment the pitcher commits to pitch to home plate. The pitcher cannot abort the pitch and try to put the runner out; this is a balk under Rule 8.

If the runner breaks too soon (before the pitcher is obliged to complete a pitch), the pitcher may throw to a base rather than pitch, and the runner may be tagged out between the bases. Past this moment, any delay in the runner's break makes it more likely that the catcher, after receiving the pitch, will be able to throw the runner out at the destination base.