A stolen base, abbreviated SB, occurs when a baserunner advances to the next base without the ball having been hit into play or a fielding error. Stolen bases are awarded at the discretion of the official scorer.
Typically a stolen base is the result of the runner running to the next base simultaneously with the pitch being thrown and reaching it before being tagged by the ball thrown by the catcher to the base the runner is trying to reach. A stolen base can also occur while the catcher is relaying the ball back to the pitcher, or when a pick-off is attempted.
A baserunner can only attempt to steal an unoccupied base, unless there is a double steal. If the runner fails in his attempt, it is a caught stealing. In situations wherein the opposing team does not attempt to catch a baserunner stealing, then the official scorer may not award the baserunner with a stolen base, and instead the advanced base is scored as defensive indifference.
A number of factors have an impact on whether a stolen base attempt will be successful: the speed of the runner, the quality of his jump from the base, the strength of the catcher's arm, and the speed of the pitcher's motion to home plate. It is easier to steal on a breaking ball than on a fastball. If the defensive team expects that a runner will attempt to steal, it can reply by either attempting a pick-off play, or by calling for a pitch-out.
As a strategy, the stolen base has risen and fallen in popularity over the years. It was a major part of the game in the Deadball Era, fell out of favor from the 1920s until the 1950s, then enjoyed its heyday from the 1960s to the late 1980s. With the offensive explosion of the 1990s, and sabermetric research indicating that it is only a useful strategy when the success rate is higher than two-thirds, the stolen base has fallen into disfavor. It is typically used more often in a low run-scoring environment and is considered a small ball tactic.
A stolen base is often abbreviated SB.
A Sports Illustrated article named what its author thought were the ten most famous steals of all time, with #1 being Jackie Robinson's steal of home in the first game of the 1955 World Series, off of pitcher Whitey Ford and catcher Yogi Berra. 
|All Time Leaders|
|Game||George Gore||7||June 25, 1881|
|Game||Billy Hamilton||7||August 31, 1894|
|Negro league Career||Oscar Charleston||182|
|Minor league Career||George Hogriever||947|
|Minor league Season||Billy Hamilton||155||2012|
|NPB Career||Yutaka Fukumoto||1065|
|NPB Season||Yutaka Fukumoto||106||1972|
|CPBL Season||Bernie Tatis||71||1997|
|AAGPBL Career||Sophie Kurys||1114|
|AAGPBL Season||Sophie Kurys||201||1946|
|AAGPBL Game||Shirley Jameson||7||July 2, 1944|
|AAGPBL Game||Lois Florreich||7||July 2, 1944|
|AAGPBL Game||Shirley Jameson||7||July 24, 1944|
|AAGPBL Game||Betsy Jochum||7||August 2, 1944|
|AAGPBL Game||Sophie Kurys||7||September 3, 1944|
|AAGPBL Game||Maddy English||7||May 21, 1947|
- John McMurray: "Examining Stolen Base Trends by Decade from the Deadball ERA through the 1970s", The Baseball Research Journal, SABR, Volume 44, Number 2 (Fall 2015), pp. 25-31.
- Pete Palmer: "Stolen Bases and Caught Stealing by Catchers: Updating Total Player Rating", The Baseball Research Journal, SABR, Volume 43, Number 1 (spring 2014), pp. 23-25.