In Major League Baseball, the wild card teams are the two teams in each of the two leagues that have qualified for the postseason despite failing to win their division. Both teams in each league possess the two best winning percentages in their respective league after the three division winners. The wild card was first instituted in MLB in 1994, with one wild-card team per league advancing to the Division Series in the postseason to face a division winner. In 2012, the system was modified to add a second wild-card team per league and pit each league's wild-card teams against each other in a play-in game—the MLB Wild Card Game—the winner of which would then advance to the Division Series and play the team with the best record. This system ensures that the two teams with the best records in each league, after the three division winners, will also get postseason berths.
One wild card per league (1994–2011)
From 1969 through 1993, division leaders in each league advanced to the League Championship Series, with the winners of each LCS meeting in the World Series. However, an expanding number of teams over the years made making the playoffs increasingly difficult. The new system was instituted in 1994 when Major League Baseball expanded from two to three divisions per league. In the new three-division leagues, each league had four teams in the playoffs. In addition to the three division winners, a wild-card team made the playoffs as the fourth seed. This was the team with the most wins amongst non-division winners. The wild-card matchup was played in the first round between the League leader in wins and the wild-card team, unless both teams were in the same division, which resulted in the wild card facing the second-best division winner in the league.
Historic anomalies
A "wild card" rule was used in the 1981 season after a players' strike wiped out the "middle third" of the season. The owners decided that the winners of either "half" of the abbreviated season would make playoffs, with the that if the same team won both halves then the team from the division with the second-best record from the second half would enter the playoffs as a wild card. However, the wild-card rule was not actually used since all four divisions had different first half and second-half winners. As a result of the hastily contrived format, the Cincinnati Reds finished the regular season with the best record in all of baseball but failed to qualify for the playoffs because they finished 0.5 game behind the Dodgers in the first half and 1.5 games behind the Astros in the second half. The Astros finished 8 games back in the first half and the Dodgers 6 back in the second.
Two wild cards per league (2012–present)
On November 17, 2011, MLB announced that it would be adding two wild-card teams to the postseason. The two wild-card teams in each league face each other in a one-game playoff. The winner of this game advances to meet the top seed in the Division Series. The revised playoff system began with the 2012 season.
Wild-card winners by year and by most wild-card titles
For each league's list of wild-card winners by year and teams with most wild-card titles, see:
Combined postseason series record as wild-card winners
– Counts one-game wild-card playoff in the statistics.
Notable wild-card team achievements
The following wild-card teams have won the World Series: the Florida Marlins, in 1997 and 2003; the Anaheim Angels, in 2002; the Boston Red Sox, in 2004; the St. Louis Cardinals, in 2011; the San Francisco Giants, in 2014; and the Washington Nationals, in 2019. Thus, three consecutive titles, from 2002 to 2004, were won by a wild card.
A wild-card team appeared in the World Series each year from 2002 to 2007.
The Baltimore Orioles, in 1996, were the first wild-card team to win a Division Series.
The Marlins, in 1997, were the first wild-card team to reach the World Series and the first to win the World Series. By winning again in 2003, they became the first team to win the World Series twice as a wild card. The Marlins are also the only team to win the World Series without ever winning a division title.
The Houston Astros were the first team to have won a wild card in different leagues. NL and AL
The following teams have qualified as a wild card in consecutive years: the Red Sox, the Astros, the Mets, the Cardinals, the Pirates, the Yankees, the Rockies, and the Athletics.