Is this getting too weird? For the second straight season, the Pacific League dominated the Central League in interleague play.
After thrashing the CL 81-59-4 in 2010, the PL whipped their more popular rivals 78-57-9 this year. The PL is now 586-534-32 in interleague play.
There are a number of potential causes, including the possibility that the PL might just be a better league.
Marines second baseman Tadahito Iguchi has suggested that a wider strike zone is one factor in the equation.
Interleague games have always been worked by umpires from both leagues. But this season, umpires are no longer affiliated with the leagues. Former CL umps now work PL games, while ex-PL officials call balls and strikes in CL clashes.
Former CL umps, Iguchi said, tend to have a strike zone wider by the width of one ball. He argues it is easier for PL pitchers to work a bigger strike zone than for CL pitchers to switch to a smaller one.
Since Opening Day, PL pitchers have allowed 7.6 percent fewer runs in games with a former CL umpire. CL pitchers, however, have allowed just 2.8 percent fewer runs pitching with an ex-CL ump.
But wait a minute. Over the previous three years of interleague play, an umpire's affiliation made virtually no difference in the number of runs scored.
Even if this is currently an advantage for PL pitchers, it won't last for long.
As strike zone widths become more standardized and batteries become more familiar with the umpires, there won't be any advantage to be had.
How about the differences in rules between the leagues? In CL parks, the pitchers bat; in PL parks, teams use the designated hitter.
Prior to this year's interleague play in the majors, Detroit Tigers manager Jim Leyland said interleague was inherently unfair to American League teams, because better-hitting National League pitchers would give their teams an advantage.
The problem with that argument is that pitchers don't get paid to hit, and most of them can't. Regardless how many at-bats a really poor hitter gets each year, he's not going to be a threat.
CL pitchers batted .070 prior to this year's interleague and .084 against PL pitching with no extra bases and five walks. PL pitchers, on the other hand, batted .098 with three doubles, a home run and nine walks. Advantage PL.
On the other hand, PL clubs have a real advantage at home, where they can use a DH. Unlike CL clubs, many PL teams have a quality DH available.
Since 2006, PL's designated hitters have a .750 interleague OPS (on-base percentage plus slugging average), 58 points higher than their CL counterparts. This advantage, however, appears to be fading, as CL DH's have had the upper hand in each of the last two seasons.
Of course, there is always the possibility that PL teams might simply be better. This is what Swallows right-hander Shohei Tateyama suggested last week.
"This is the seventh year , and they've won [more games overall] six times. Perhaps, the PL is just stronger," he said. "In those big parks, with the DH rule, you'd think PL pitchers might develop more.
"It is harder to learn how to pitch in the CL, because if you start a game poorly and a pinch-hitting opportunity comes up, you can be out of the game after three innings. In the same circumstances, a PL pitcher might work seven innings.
"They [PL pitchers] can also just concentrate on pitching. They don't have to think about hitting at all. That makes a PL pitcher's job easier."
That argument makes lots of sense.
If playing conditions help the PL get more out of its pitchers, we would expect to see more career win leaders begin their careers in the PL, and we do.
Among the 20 active pitchers with the highest career win totals, 12 spent their formative years in the PL.
If the DH is the reason--as Tateyama suggests--then we should see the same effect in the major leagues, and we do.
Of the majors' 21 top active winners (two pitchers are tied for 20th), 13 developed in the DH-using AL.
If the DH has helped make PL pitchers--and in turn the PL--better, this is what one would expect to see. It's not a definitive answer, but it is an interesting thought.