Major League Baseball is an organization that operates two leagues, the American and the National League, and has existed since 1903. It is comprised of 30 teams; 16 teams in the National League, and 14 Teams in the American League. The Major League baseball season runs from March or April until September or October, and consists of 162 games (or 163 in the event of a tiebreaker). Spring training comes before the main season, usually in February. The playoffs follow the regular season, culminating in the World Series in October. The only difference between the play of the two leagues is that American League teams are permitted to allow a designated hitter to bat in place of the pitcher.