MLB’s Playoff Rule Reset: No Automatic Runner, but Two ABS Challenges

Before the September 29 Wild Card slate begins, MLB’s postseason rules reset the extra innings starting point: no automatic runner starts on second base in October. Four best of three Wild Card Series open today, with Phillies at Braves at 2 p.m. ET, White Sox at Astros at 5 p.m. ET, Red Sox at Yankees at 8 p.m. ET, and Cubs at Padres at 10 p.m. ET. That schedule makes the rule change worth settling before the first pitch. [1] The postseason format does not ask readers to predict a result. It asks them to separate three pieces of game procedure that can appear in the same late inning: the automatic runner rule, manager replay challenges, and the ABS Challenge System. Each has its own trigger and its own limits. Combining them produces the wrong picture of what is available during a game. The October extra innings reset MLB’s automatic runner rule applies only to regular season games. In that setting, an extra inning begins with a runner on second base. MLB’s postseason format says that runner is not used in October. Postseason extra innings begin without an automatic runner, which means neither club opens the inning with a runner placed at second. [2] [3] USA Today also confirmed the postseason approach on the morning of September 29. The point is simple, but it matters because regular season habits can carry into the playoff calendar. A regular season extra inning and a postseason extra inning do not begin from the same base state. [5] That distinction is a rule check, not a forecast. It does not identify a winner, set an expected score, or settle a market. The game rule also does not establish how a particular sportsbook handles any market. Provider terms are separate documents, and only a provider’s published rules can answer a settlement question for that provider. The clean pregame note is short: do not import the regular season runner on second into an October extra inning. The postseason format removes that starting runner. Everything that follows still depends on the actual game, the plays that occur, and the official result. Two systems, two separate counts Manager replay challenges and ABS challenges are not one challenge bank. MLB says managers begin postseason games with two replay challenges, compared with one in the regular season. That count belongs to the manager replay system. [3] The ABS Challenge System has a separate count. Each team begins with two ABS challenges. A team keeps an ABS challenge if the challenge succeeds. If a team starts an extra inning with no ABS challenges left, it receives one ABS challenge for that inning. Those rules govern ABS only. They do not add to, replace, or convert manager replay challenges. [4] The people who can initiate an ABS challenge are limited. Only the batter, pitcher, or catcher may make one. The challenge must come immediately, and it cannot come from dugout assistance. MLB presents ABS as a process for a ball strike call, not as a manager replay action. [4] A useful way to keep the systems straight is to ask two questions. First, is the issue a manager replay matter? The team has its postseason replay challenges for that system. Second, is it an ABS challenge on a ball strike call? The eligible batter, pitcher, or catcher acts under the separate ABS rules. The answers do not combine into four interchangeable opportunities. Extra innings add another reason to track the systems separately. The automatic runner rule tells you how an inning begins. The ABS rule describes a limited challenge that can be available when a team enters an extra inning with none left. Manager replay challenges remain their own process. Similar timing does not turn these rules into one system. This is also why the word "challenge" needs context. A broadcast can discuss a replay review and an ABS challenge during the same game, yet the terms point to different procedures. Readers can avoid confusion by naming the system before counting the challenges. SBA Takeaway October baseball changes the extra innings starting point. No automatic runner begins on second in the postseason. Keep that fact separate from the two manager replay challenges that begin a postseason game and the two ABS challenges each team also receives. [3] [4] The ABS count has its own retention rule and its own extra inning provision. Its eligible challengers are the batter, pitcher, and catcher, not the manager. The manager replay count has a different home in the rulebook. Treating the systems as distinct keeps a late game explanation accurate without turning a rule change into a prediction. For the September 29 slate, the right process is to read the playoff rules as they apply to the game on the field. A postseason extra inning starts without the regular season runner. An ABS challenge is not a manager replay challenge. Those are clear procedural facts, and they do not tell anyone what the final score will be. Sources - [1] 2026 postseason schedule, results and how to watch - [2] Automatic Runner - [3] MLB’s postseason format, explained - [4] Everything you need to know about the new ABS Challenge System - [5] MLB playoffs extra innings rules: Is there a ghost runner? Related Reading - The NCAA Says Replay Protocol Failed. The 13 to 12 Final Still Stands. - Rangers Tie Astros in AL West, but Houston Has the Tiebreaker - White Sox and Guardians: Price the Series Before One Game