The Wild Card Series is the first round of the postseason in Major League Baseball. It consists of two best-of-three series in each league, with all games played in the home ballpark of the top seeded team. The four teams participating are the third-ranked division winner, who is seeded #3, and three wild card teams ranked #4 to #6. Team #3 hosts team #6 in the first Wild Card Series, and Team #4 hosts Team #5 in the second Wild Card Series. The winner of the first series goes on to play the #2-seeded team in the Division Series, while the winner of the second series plays the #1 seed. This format will first be used as part of the 2022 Postseason.
There was a first use of the Wild Card Series in 2020 as a result of the special postseason format adopted due to the shortened season resulting from the coronavirus pandemic. That year, all postseason teams took part in the "Wild Card Series", pitting the three division winners in each league and the top second-place team hosting the other two second-place teams, and the next two best teams in best-of-three format, with all of the games played in the home ballpark of the higher-ranked team. The winners then moved on to the Division Series, as per other years.
Wild Card Series
American League Wild Card Series
National League Wild Card Series