The Wild Card Series is a set of games that serve as the opening round of the Major League Baseball (MLB) postseason. The Wild Card round was initially introduced in 2012 as a single-game playoff between two wild-card teams in each league, with the winner advancing to the Division Series. With the adoption of MLBs new collective bargaining agreement in November 2011, baseball commissioner Bud Selig announced that a new playoff system would begin within the next two years; the change was ultimately put into place in 2012. This format was used through the 2019 season. In 2020, after the shortened 60-game regular season, the first round of the MLB postseason consisted of four Wild Card Series in each league, each series being a best-of-three hosted by the higher seed. Eight teams from each league participated: three division winners, three division runners-up, and two wild card teams (the two remaining teams with the best records, based on winning percentage) . In 2021, the postseason returned to its pre-2020 format, with the two Wild Cards in each league playing a single-game playoff. However, in 2022, a third Wild Card spot was created in each league, bringing the total number of postseason teams to 12. The Wild Card Series returned as a best-of-three, with all three games in the home site of the higher seed. The top two division winners in each league receive byes to the Division Series, while the other four teams in each league play best-of-three series in the Wild Card round, with the higher seed hosting all three games. Each leagues No. 1 seed faces the winner of the Wild Card Series between the Nos. 4/5 seeds in their respective league, while the No. 2 seed takes on the winner of the Nos. 3/6 series.