American League Division Series
The first Division Series was played in the strike shortened 1981 MLB season.  Teams in first place before the strike took on teams in first place after the strike.  In 1994, the Division Series was added for good.  Both leagues were split in to three divisions each; and the wild card was added as well.  However, a strike cancelled the rest of the 1994 season, including the playoffs. The current-day Division Series thus began the play in 1995.