Starting in 2007, both leagues will play 144-game schedules and have the top three teams in each league advance to a playoff to decide the league champion.
This season, teams in the Central League play 146 regular season games. Teams in the Pacific League play 136 regular season games.
The Central League's representative in the Japan Series will be the regular season champ. Presently, the Chunichi Dragons have a big lead (9 games) over the second place Hanshin Tigers.
The Pacific League's representative in the Japan Series will be one of the teams that finish in the top three. Presently that would be the Seibu Lions, the Fukuoka Softbank Hawks, and the Hokkaido Nippon Ham Fighters. If the season ended now, the second and third place teams (Softbank and Nippon Ham) would play a best of three playoff. The winner of that series would play Seibu in a FOUR game playoff, with Seibu being spotted one win. In other words, the winner of the first series would have to win three games before the champion wins two. I will be in Japan in time to see the second stage of the PL playoffs and I hope to be at the stadiums to see the games. Wherever they may be.
The number of interleague games is being reduced from 36 to 24 games for 2007. Presumably each team (there are six in each league) would play two game home-and-home series.
The last two Japan Series champions, Seibu in 2004 and Lotte in 2005, did not finish first in the regular season. But both benefited from playing a Central League champ in the Japan Series that hadn't played a game in over two weeks.
The Central League still has pitchers bat. The Pacific League uses the DH.