Japanese baseball is full of paradoxes. A nation schooled in the righteousness of the sacrifice bunt lusts after the long ball, while the less popular Pacific League has clearly become the best of Japan’s two major leagues.
What prompted that thought was the news this week that the Japan Series champion Fukuoka Softbank Hawks are turning their spacious dome with its imposing outfield ramparts into a home run park. Yafuoku Dome is being transformed with inner fences that will give the stadium similar dimensions to Tokyo Dome, whose power allies are the shallowest in Japan.
The Japanese story is here: http://www.daily.co.jp/baseball/2014/12/24/0007607586.shtml
Essentially, the isssue is that the Hawks hit just 95 home runs over their 144 regular season games, the ninth fewest in Japan. Some must be longing for the days before the 2011 introduction of a standard ball, when teams could just choose livelier balls for their home games. But with everyone forced to use the same ball, the club is bringing in the fences, creating what the Japanese call “lucky zones,” where cheap home runs can drop in. It remains to be seen how the change will impact Softbank’s performance, but it’s kind of sad when a good PL club feels it has to take a page out of the Central League playbook.
It has long been a given that Japan’s two leagues are equal. Although that view remains the accepted norm in Japan, it is hard to support when one looks at the records since interleague play was introduced in 2005. In 1,592 games between the leagues, including the Japan Series and excluding ties, PL teams have a .526 winning percentage — that is much lower than expected (.545) given the number of runs scored and allowed.
http://jballallen.com/files/League results.pdf
Some of the talent gap might be explained if the CL clubs were losing their biggest stars to the majors and to the PL — instead of it being the other way around. Yu Darvish, Hisashi Iwakuma and Masahiro Tanaka all came out of the PL. The bulk of quality players going to the States have been from the PL, while until very recently no stars in their prime left the CL as free agents to sign with PL clubs.
Given the just mentioned cast of former PL characters, the common explanation for the PL’s interleague dominance is better pitching, and that appears to be part of the reason but not the main one. Although offensive levels vary quite a bit from month to month, NPB’s interleague action conveniently starts in the middle of May and wraps up before the end of June. A look at how well teams hit and defend depending on whether their visiting opponents are in the PL or CL in May and June is instructive.
The biggest difference between the two leagues appears to be CL clubs not having big-hitting designated hitters when they play in PL parks. Since 2006, when detailed game data became available, PL designated hitters have posted a .747 OPS in interleague, while their CL rivals have managed only .681. While the CL’s pitchers make up some of that slack, their edge over their PL counterparts has been just .269 to .246. Indeed, the average visiting OPS in the main PL parks in May and June drops from .713 to .655 when the opponents are from the CL.
http://jballallen.com/files/League to league differences.pdf
But that’s not the end. PL teams also outperform CL teams when visiting CL parks (.713 to .700) without the DH. As for the PL’s famous pitching, that shows up in their home parks, when the home offenses pick up against visiting CL pitchers, seeing an average increase in OPS from .704 to .718.
These data cannot explain the whole story, but they do indicate the designated hitter gives the PL a real advantage. The exception is the CL’s best interleague team, the Yomiuri Giants. They happen to have NPB’s deepest pockets and usually a few guys on the bench who could cut it as front-line DHs. Over the past nine seasons, the Giants’ interleague DHs have a .744 OPS, just a hair shy of the PL average.
The Hawks and the rest of the PL have had a pretty good thing going on, playing in huge, pitcher-friendly parks in a league that uses the DH. The PL game is a little faster with more emphasis on fielding and base running, but there is something about the home run that many cannot resist and that seems like a step backward.
Each main park’s individual OPS averages for league and interleague play from 2006 to 2014 can be found here: Interleague park data.pdf