The MLB postseason operates under a different set of standards in several key areas. Beyond the shortened series formats used to determine who advances to the World Series, Major League Baseball alters specific ground rules, most notably eliminating the controversial “ghost runner” rule, which automatically places a runner on second base to start extra innings.
There is no automatic runner on second during October baseball for good reason: placing a runner in scoring position fundamentally reshapes traditional baseball strategy. In October, league officials prefer to avoid scenarios where a simple sacrifice bunt and a fly ball can walk off a high-stakes playoff game without a single hit.
When MLB initially introduced the automatic runner during the pandemic-shortened 2020 season, the goal was to manage workload and preserve player health. By expediting extra-inning games, the league sought to prevent bullpen burnout and avoid marathon late-night contests over the course of a grueling 162-game regular-season grind.
Playoff baseball also enforces unique protocols regarding weather delays and official games when teams are fighting to secure a spot in the next round. Yet despite these select tweaks, the fundamental dynamics on the field remain largely identical to regular-season play.
Ben Rice #22 of the New York Yankees celebrates as he round the bases.
Other key MLB postseason rule changes
Beyond the removal of the automatic runner in extra innings, MLB implements several distinct structural changes during the postseason that shape how managers handle their benches and bullpens. Here are the major rule adjustments in effect for October:
- Replay challenges: Managers receive two replay challenges per game in the postseason, up from the single challenge granted during the regular season. As always, managers retain a challenge if a call is successfully overturned.
- Roster size caps: Active postseason rosters shrink back down to 26 players, down from the expanded 28-man rosters allowed in September. Teams are capped at a maximum of 13 pitchers, compared to the 14 allowed during the final month of the regular season.
- Weather delays & suspended games: Playoff games cannot be shortened or called early due to inclement weather. If a postseason game is halted by rain at any point—even after becoming an official game in the 7th or 8th inning—it is suspended and resumed from the exact point of stoppage. All nine full innings (or more) must be played to completion.
- Expanded umpiring crew: MLB adds two outfield umpires along the left-field and right-field foul lines, expanding to a six-umpire crew to ensure maximum precision on boundary, catch/trap, and fair/foul calls.
- Position players pitching: In the postseason, position players can pitch if a team is leading or trailing by 6 or more runs at any point, or during extra innings. This is a shift from regular-season rules, which require a team to be trailing by 8+ runs or leading by 10+ runs in the 9th inning.
These strategic rule modifications give managers greater flexibility to manage their rosters and game plans, particularly in short-burst matchups like the Wild Card Series and Division Series where every single inning carries immense weight.
Key takeaways
- Ghost runner rule is eliminated during postseason extra innings to prevent easy walk-off wins.
- Managers receive two replay challenges per game during the postseason instead of one.
- Postseason active rosters shrink to 26 players with maximum 13 pitchers allowed.
