Most leagues send their league winners straight to the final. NPB does something stranger: it gives the pennant winner a built-in advantage and makes them prove it anyway. Welcome to the Climax Series.
The format
After the 143-game regular season, the top three teams in each league qualify:
- First stage: the 2nd-place team hosts the 3rd-place team in a best-of-three series.
- Final stage: the first-stage winner travels to the league winner, who starts with a one-game advantage — effectively, the challenger must win four games to advance. (A 2026 rule change can make that advantage two games; see below.)
- Japan Series: the two final-stage winners meet in a best-of-seven finale.
Why it matters
The Climax Series rewards consistency — winning the pennant is genuinely valuable — while keeping October dramatic. A hot third-place team can ride momentum all the way to the Japan Series, and several have come close. It also means the regular season never feels "meaningless": every win moves a team up the table, and the tiebreakers are tight.
Win the pennant, get a head start. Fall behind, and the math gets cruel.
History and the 2026 change
The Climax Series was introduced in 2007, modeled partly on the idea that a short playoff can correct an imperfect regular season. Before that, each league's pennant winner advanced directly to the Japan Series — a format that still shapes how Japanese fans talk about "the road to the Japan Series."
2026 brought a change: if the first-stage winner finished 10 or more games behind the pennant winner, or finished below .500, the pennant winner now receives a two-game advantage and the stage can run to seven games (first to five). Without that trigger the traditional six-game, first-to-four format applies.
2026: the matchups
In 2026 the Climax Series runs October 10–20. The First Stage (October 10–12): Giants vs. DeNA at Tokyo Dome and Seibu vs. Nippon-Ham at Belluna Dome, both best-of-three. The Final Stage begins October 14: the winners travel to pennant winners Hanshin (Koshien) and SoftBank (Mizuho PayPay Dome). Hanshin carries the conventional one-game advantage; SoftBank carries two, and the stage can run to a seventh game on October 20. The survivors meet in the SMBC Japan Series from October 24. Full details: the postseason guide.