No, stealing a base does not mean sneaking onto the baseball field at night and physically carrying off a base plate. Instead, it refers to the event in which a baserunner progresses to the next base without help from a teammate's hit.
With high stakes and only seconds to spare, stealing a base is a rare and a risky undertaking that, if unsuccessful, can derail the team's momentum. For instance, influential baseball statistician Bill James has proposed that attempts to steal a base may be more detrimental than beneficial for a team, unless the attempting baserunner has a success rate of at least 70%.
A runner on first base will stand slightly toward second base. This is called leading off. When the pitcher begins his pitching motion, the runner will sprint toward second base. He only has a few seconds to get there safely, because once the baseball reaches the catcher, the catcher will throw it to the second baseman as fast as he can.
If the runner reaches the base before the second baseman can tag him out, the runner is safe and now occupies second base. Attempting to steal a base is a gamble that only the speediest base runners are willing to take, and often only in low-risk situations (for example, when there are less than two outs).
Sometimes, a potential base-stealing runner is put out even before he has the chance to steal the base. Runners often stand near the base they are currently on, but in the direction of the next base. This is because runners are not required to touch the base when someone is at-bat, so they take advantage by standing slightly closer to the next base. Runners who are planning to steal will try to get as far in advance as they can get, which puts them at the risk of being picked off.
Pickoffs most often occur at first base: Before his pitch, the pitcher will quickly throw the baseball to the first baseman, who tries to tag the potential base-stealing runner with the baseball. If the first baseman tags the runner before the runner touches first base, the runner is out and the pickoff is successful.
Double steals are rare occurrences in baseball. They may refer to two base runners stealing bases in the same play (either simultaneously or with a slight delay between them), or a base runner stealing two bases in one play.
Base runners do not have to tag up on a foul tip and can also steal a base. However, it is a foul ball if the foul tip isn't caught and runners must return to their previous base, even if the steal was successful.
Runners can not advance to the next base on an interference call. For example, if the umpire interferes with the catcher's attempt to make a play on a steal or pick, the runner will be forced to return to the previous base.
In order to successfully steal a base, timing is absolutely crucial. Many baserunners hence only attempt to steal a base while the pitcher is throwing the ball to home plate. This is due to Baseball's Rule eight, which states that once the pitcher commits his set position to one specific direction, he must follow through. If the pitcher is found guilty of "balking" - changing his mind mid-pitch and attempting to throw elsewhere - all the baserunners will be allowed a free walk to their next bases. By waiting until the pitcher has committed to throwing towards home plate, the baserunner is able to ensure that he has the maximum amount of time to safely make it onto the next base.
Most baserunners attempt to steal second base. Again, this has to do with deceiving the pitcher. Statistically, there is a higher percentage of right-handed pitchers than left-handed pitchers. Furthermore, the set position of a right-handed pitcher requires him to turn his back on first base, effectively creating a blind spot. By waiting until the pitcher has completely turned away and has diverted his attention elsewhere, a baserunner on first base can maximize the chances of safely making it onto second base.
In short, stealing a base is all about being able to read the pitcher. For instance, there may also be specific tell-tale signs that provide a clue as to which direction the pitcher may throw. Through careful observations, it may be possible to detect that a certain pitcher always shifts his back leg or digs in his toes when he is about to enter the set position towards home plate, but not elsewhere. Another common giveaway is that the pitcher may always look towards a specific direction before pitching towards home plate, but not anywhere else.
While physical speed and agility are, without a doubt, absolutely essential when stealing a base, equally as important are timing and the ability to make quick decisions. Within five seconds, the baserunner must be able to determine whether or not attempting to steal a base will be the best course of action - and follow through. There is very little room for error.
Although it may seem obvious, it is illegal to "reverse steal," or steal a base backward. Because the action is so counterintuitive - the goal of a baserunner is to safely run from first base to home plate, not to run back to first base - the rule prohibiting this action had not even been written until 1919.
Herman "Germany" Schaefer, an MLB player widely known for his sense of humor and various pranks during his games, is famous for being the only player in history to have stolen first base. During a game in 1908, Schaefer had been on second base with a teammate on third. In order to distract and draw the pitcher's attention away from his teammate so that he could safely steal home, Schaefer spontaneously decided to run backward to first base - back to where he had started. According to accounts provided by teammates, everyone had stood dumbfounded, in shock at what had just happened. However, as there had been no rule prohibiting such actions, the umpires had little choice but to let the play stand.
After Schaefer's death in 1919, the MLB rulebook was revised to include Rule 7.08i, which states that a player who runs in reverse order or will be called out by the umpire.