NPB's postseason has always been unusual. In 2026 it got stranger: a new rule gives the league champion a two-game head start in one league but not the other. Here is everything you need to follow October.
The two-round structure
The regular season runs to 143 games. When it ends, the top three clubs in each league qualify for the Climax Series, which has two rounds.
- First Stage — best of three (Oct 10–12). The 2nd-place team hosts the 3rd-place team. First to two wins advances. Both series are on the 2nd-place club's home field.
- Final Stage — from Oct 14. The First Stage winner travels to the league champion, who hosts every game. The league champion walks into the series with an advantage.
The survivors from each league meet in the Japan Series, a best-of-seven that opens on October 24.
The advantage, and when it doubles
Traditionally the league champion starts the Final Stage with a one-game advantage in a six-game series, first to four wins. The challenger therefore usually needs to win four games; the champion needs three.
For 2026 the leagues added an expansion clause. If either of these is true, the league champion gets a two-game advantage and the stage becomes seven games, first to five:
- the First Stage winner finished 10 or more games behind the league champion, or
- the First Stage winner finished the regular season below .500.
The point is to stop a large gap from being meaningless — and to reward dominant regular seasons.
Exactly ten games of separation triggers the clause; exactly .500 does not.
Who it applies to in 2026
Both leagues finished with enough separation for one and not the other, so the two leagues play under different rules this year.
- Pacific League — the rule applies. SoftBank (91 wins) finished 11.5 games ahead of Seibu and 13 ahead of Nippon-Ham. Whichever advances will have to win five games; SoftBank needs three. A seventh game is scheduled for October 20.
- Central League — it does not apply. Hanshin (79 wins) finished 2.5 games ahead of the Giants and 7.5 ahead of DeNA, and both challengers finished above .500. The Central plays the traditional six games, first to four, with Hanshin holding a one-game advantage.
The 2026 schedule
- Oct 10–12: First Stage — Giants vs. DeNA at Tokyo Dome; Seibu vs. Nippon-Ham at Belluna Dome.
- Oct 14–19: Final Stage, Games 1–6.
- Oct 20: a seventh Final Stage game, if the Pacific League series needs one. For the Central League this date is a reserve day.
- Oct 24 – Nov 1: the SMBC Japan Series at the Central League champion's park first.
Why it matters
A first-stage team that goes on a long October run still has a realistic path, but it has to win more games to get there — and a dominant regular season is now worth something concrete in October. For visiting fans, the practical takeaway is simple: in the Pacific League, expect longer series and more night games.