Fans of both the American and National Leagues swear their league is best. I obviously think the NL is better for a variety of reasons, most notably that the DH is absurd, and the average time of an American League game is something like 9 hours. Now, the DH is essentially a spot for fat guys, so you'd think I'd enjoy that, but even creating a roster spot specifically for fat dudes isn't as entertaining as watching Pedro Martinez swing a bat with a knowing smirk on his face. Also, fat guys fielding is a significant part of their fat guy charm. Finally, to make matters worse, AL baseball tends to center around the Yankees and the Red Sox, which would probably be the least interesting rivalry in the world if not for the great Bristol Palin-Meghan McCain throwdown.
But all kidding aside, currently, there's an interesting difference between the two leagues: the degree to which each leagues' contenders, intentionally or not, are built around a specific philosophy: Lots of frontline pitching in the NL, and tons of offense in the AL. The perception has always been this way, but the difference is really striking right now.
If you look at the three best teams in the National Leauge this season -- the Phillies, Braves, and Giants -- they are all being powered entirely by pitching. In fact, those are the three best pitching staffs in all of baseball by xFIP and FIP (all numbers from Fangraphs). Milwaukee, tied for the NL Central lead, is fourth in xFIP. Meanwhile, even St. Louis, tied with the Brewers, ranks a respectable No. 9. These teams, generally, aren't very good offensively, particularly the Braves, Giants and Phillies (though admittedly injuries and slumps for Buster Posey, Jason Heyward, Dan Uggla and Chase Utley have something do with this).
In the AL, the opposite story plays out. If you stopped the season today, Boston, Detroit, Texas and the Yankees would make the playoffs and those clubs don't pitch well. The best of the bunch is the Yankees, 12th in baseball and powered entirely by the amazing C.C. Sabbathia and the amazing C.C. Sabbathia's gut, followed the Rangers at 17, and the Red Sox and Tigers way down at 26 and 27, respectively. If you want to expand to five teams, add Cleveland, the next closest team to a playoff spot, which ranks 15th. Even Anaheim, another contender, who you'd think would have a good pitching staff with Jered Weaver and Dan Haren, ranks all the way at No. 14.
This isn't terribly surprising when you think about it: the Giants, Phillies and Braves were all clearly built on their pitching staffs. But it is an interesting trend. The Phillies gladly bailed on Jayson Werth in the offseason to sign Cliff Lee (a decision that now seems even more brilliant in retrospect). The Giants -- sans Buster Posey -- have one position player you could describe as good, Pablo Sandoval. Similarly, the Braves are built on a combination of very good starting pitching and tremendous relief pitching. The Brewers are the exception here, but if not for Zach Greinke's injury and some bad luck, their pitching would be even better. Plus their offense is skewed downward by giving play time to The Gomez, among others terrible players.
You simply can't make the same argument about most of the AL teams. The Yankees rotation is essentially put together as C.C. Sabbathia and whoever they can find. Can you even name a Detroit pitcher besides Justin Verlander and Rick Porcello? An Indians pitcher besides Justin Masterson? The Red Sox rotation is the best of the bunch on paper, until you remember that John Lackey is horrible at this point, and Clay Bucholz is relatively unproven, and injured for that matter. But those teams -- and particularly the Yankees and the Red Sox -- simply have no holes in their lineups, running out good hitter after good hitter (well, except Derek Jeter).
If you arbitrarily go back five years to 2006, you'll see the playoff teams's pitching success far more scattered by league. The AL playoff teams ranks by xFIP were: Twins (1), Tigers (11), Yankees (22) and Athletics (23) and the NL teams ranks were Dodgers (4) Mets (8), Padres (9), Cardinals (18), which is to say, certainly the NL pitched better, but not nearly to the degree we're seeing now.
I'm not sure how much this means, or whether it's pure coincidence that the NL teams we're talking about developed Cole Hamels, Matt Cain, Madison Bumgarner, Tim Lincecum, Gallardo and Jaime Garcia, and that the AL teams -- most notably the Yankees -- have done nothing of the sort. Maybe it comes down to a fluke, Cliff Lee and Roy Halladay both ending up in Philly as opposed to one ending up in New York and one in Boston, as you'd generally expect. But it is, at the least, an interesting phenomena.