American League Division Series

The ALDS is a best-of-five series where the wild card team is assigned to play the divisional winner with the best winning percentage in the regular season in one series, and the other two division winners met in the other series with the team with the second best winning percentage, getting home-field. (From 1998 to 2011, if the wild-card team and the division winner with the best record were from the same division, the wild-card team played the division winner with the second-best record, and the remaining two division leaders played each other.) The two series winners move on to the best-of-seven ALCS. According to Nate Silver, the advent of this playoff series, and especially of the wild card, has caused teams to focus more on "getting to the playoffs" rather than "winning the pennant" as the primary goal of the regular season.[1]

Beginning with the 2012 season, the wild card team that advances to the Division Series was to face the number 1 seed, regardless whether or not they are in the same division. The two series winners move on to the best-of-seven ALCS. Home-field advantage goes to the team with the better regular season record (or head-to-head record if there is a tie between two or more teams), except for the wild card team, which never receives the home field advantage.

Beginning in 2003, MLB has implemented a new rule to give the team from the league that wins the All-Star Game with the best regular season record a slightly greater advantage. In order to spread out the Division Series games for broadcast purposes, the two ALDS series follow one of two off-day schedules. Starting in 2007, after consulting the MLBPA, MLB has decided to allow the team with the best record in the league that wins the All-Star Game to choose whether to use the seven-day schedule (1-2-off-3-4-off-5) or the eight-day schedule (1-off-2-off-3-4-off-5). The team only gets to choose the schedule; the opponent is still determined by win–loss records.

Initially, the best-of-5 series played in a 2–3 format, with the first two games set at home for the lower seed team and the last three for the higher seed.[2][3] Since 1998, the series has followed a 2–2–1 format,[4] where the higher seed team plays at home in Games 1 and 2, the lower seed plays at home in Game 3 and Game 4 (if necessary), and if a Game 5 is needed, the teams return to the higher seed's field. When MLB added a second wild card team in 2012, the Division Series re-adopted the 2–3 format due to scheduling conflicts. It reverted to the 2–2–1 format starting in 2013.[5]

In the sortable table below, teams are ordered first by number of wins, then by number of appearances, and finally by year of first appearance. In the "Season(s)" column, bold years indicate winning appearances.