The Wild Card Series (WCS) is the opening round of the Major League Baseball (MLB) postseason, covering both the American and National Leagues. Originally a single, do-or-die Wild Card Game from 2012 to 2019 (and again in 2021) introduced under Commissioner Bud Selig, it became a permanent best-of-three series starting in the 2022 season, after a one-off trial in 2020. In the current format, the three division winners in each league are seeded #1–3, while the three best non-winners are wild cards (#4–6); the top two seeds get byes, while seeds #3–6 play in two best-of-three series, with the higher seed hosting every game. This expansion, which replaced the long-standing system of a single wild card team per league (used from 1995–2011), also abolished regular-season-extending tie-breaker games like the famous "Game 163." The winners of these wild card series then advance to face the top division winners in the Division Series, completing the new playoff bracket.