MLB playoff rules differ from the regular season in a few important ways: there is no automatic runner on second base in extra innings, games cannot end in a tie, the Wild Card Series are played on three straight days at one park, and the bracket does not reseed after upsets. The pitch clock, 26 man rosters and the universal DH all carry over. The chart below covers the 12 rules that matter most, starting with the Wild Card Series that opens Tuesday, September 29.
MLB postseason rules
12 rules that decide the playoffs, and which ones change in October
Tagged by whether the rule is different from the regular season, a bracket rule, or the same as always.
No automatic runner in extra inningsThe regular season rule that starts extra innings with a runner on second does not apply in October; extra innings are played straight up until someone wins.
DIFFERENT IN OCTOBER
No tie gamesEvery postseason game is played to a winner, no matter how long it takes.
DIFFERENT IN OCTOBER
No off days in the Wild Card roundThe best of three series are played on consecutive days, Tuesday through Thursday, all at the higher seed’s park.
DIFFERENT IN OCTOBER
No reseedingThe bracket is fixed: the No. 1 seed plays the winner of 4 vs. 5, and the No. 2 seed plays the winner of 3 vs. 6, even if a lower seed pulls an upset.
BRACKET
Byes for the top two seedsThe two best division winners in each league skip the Wild Card round and open the Division Series at home on Saturday, October 3.
BRACKET
Home field by recordWithin a series, the team with the better regular season record hosts more games; in the World Series, home field goes to the pennant winner with the better record.
BRACKET
Series formatsWild Card: best of three, all at one park. Division Series: best of five, 2, 2, 1. LCS and World Series: best of seven, 2, 3, 2.
BRACKET
Pitch clock stays onThe pitch clock, pickoff limits and shift restrictions used all season apply in the postseason.
SAME AS THE REGULAR SEASON
26 man rostersTeams set a 26 man roster with a maximum of 13 pitchers before each series and can change it between rounds.
SAME AS THE REGULAR SEASON
Injured playersA player replaced on the roster because of an injury during a series is not eligible to return until the following round.
DIFFERENT IN OCTOBER
Universal DHThe designated hitter is used in every game in both leagues.
SAME AS THE REGULAR SEASON
Replay reviewManagers have one challenge per game and get a second if the first is successful, plus umpire initiated reviews late in games.
SAME AS THE REGULAR SEASON
Rules are set by MLB and the players’ association and can change from year to year; the format above has been in place since the 12 team playoffs began in 2022.
How the 12 Team Format Works
Six teams from each league make the playoffs: three division winners and three wild cards. The two best division winners get byes to the Division Series. The other four teams are seeded 3 through 6, with the No. 3 seed (the third division winner) hosting the No. 6 seed and the No. 4 seed hosting the No. 5 seed in best of three Wild Card Series. Ties in the standings are broken by head to head record, not by extra games, so there has been no Game 163 since the format began.
Why There Is No Ghost Runner
The automatic runner was introduced to keep regular season games from running late and wearing down pitching staffs. MLB has never used it in the postseason, where the stakes justify playing extra innings to a natural finish. The longest postseason game in history, Game 3 of the 2018 World Series, went 18 innings.
Related
MLB playoff bracket · Wild Card Series schedule · Division Series schedule · What is the magic number
Official rules and definitions are published on MLB.com.
