**The 2026 MLB postseason opened with Division Series games on October 3 following Wild Card rounds that featured one extra-inning contest (Phillies-Braves Game 2).** High-seed teams like the Dodgers, Brewers, Rays, and Guardians advanced with strong pitching staffs and bullpen depth, increasing the chance of low-scoring, extended games in best-of-five series. Factors such as starter matchups, bullpen usage patterns, and late-inning leverage situations will influence extra-inning potential, especially in tight series where managers lean on relievers. Historical postseason marathons have reached 18 innings, often in NL or ALCS or World Series games with elite pitching. Schedule compression and travel between East and West Coast clubs add fatigue variables that could extend contests, while weather or venue effects remain secondary early in the bracket.