You know who should care about whether or not one league is superior to the other? Baseball analysts. Analysts on the Internet or analysts who work for baseball teams, who have to worry about things like league adjustments when evaluating a player's performance. Outside of that, it doesn't matter. The All-Star Game pits one league against the other, but it pits only the best players against the best players, and it's one game. The World Series is supposed to match the best team in the American League against the best team in the National League, but it doesn't always feature the best teams, one team is only one representative, and the series is limited to four-to-seven games. If you aren't an analyst, you shouldn't be too concerned with league superiority or inferiority.
Yet people still are, because people are sports fans, and sports fans are irrational. In recent years, the AL has dominated the NL in interleague play, and this has caused fans of AL teams to become obnoxiously smug. In response, this has caused NL fans to be obnoxious back, with no one pausing to consider that they're getting all emotional over a league. Nobody roots for leagues. I did one time see a guy wearing a blank All-Star Game jersey who wasn't at the All-Star Game, but he was homeless. The most likely possibility is that the jersey was a donation. An alternate possibility is that this is something that happens to people who get emotionally invested in leagues.
Anyhow, I don't think it's worth becoming emotional over league performance. I do still think it's worth examining league performance for the sake of curiosity, and right now we're exactly a third of the way through 2012's slate of interleague play. So this seems like a good time to check out the results. Fans of the Nationals might assume that the National League is doing better, after their team went into Boston and swept the Red Sox. Fans of the Yankees might assume that the American League is still in control, after their team hosted its crosstown rivals and swept the Mets. How do their assumptions check out?
Over 84 interleague games, the AL has won 46 of them, good for a 54.8 winning percentage. In the history of interleague play, that would be the third-highest winning percentage ever, albeit a great distance behind No. 2 and No. 1. A year ago, the AL had a 52.0 winning percentage. The NL hasn't won at least half of the games since 2003. The full history:
Year | AL Wins | NL Wins | AL Win% |
1997 | 97 | 117 | 45.3% |
1998 | 114 | 110 | 50.9% |
1999 | 116 | 135 | 46.2% |
2000 | 136 | 115 | 54.2% |
2001 | 132 | 120 | 52.4% |
2002 | 123 | 129 | 48.8% |
2003 | 115 | 137 | 45.6% |
2004 | 126 | 125 | 50.2% |
2005 | 136 | 116 | 54.0% |
2006 | 154 | 98 | 61.1% |
2007 | 137 | 115 | 54.4% |
2008 | 149 | 103 | 59.1% |
2009 | 137 | 114 | 54.6% |
2010 | 134 | 118 | 53.2% |
2011 | 131 | 121 | 52.0% |
2012 | 46 | 38 | 54.8% |
We could stop there, but I don't want to, since the leagues have played just the equivalent of roughly half a full season. Over small samples, win/loss records can be deceiving. Over even bigger samples, win/loss records can be deceiving. What if we go beyond wins and losses and check out run differentials? That's probably going to be a better indicator of league performance.
So far in 2012, the AL has scored 410 runs, and the NL has scored 335 runs. For the American League, that's good for a Pythagorean 59.1 winning percentage. That's the second-highest Pythagorean winning percentage in interleague history, a hair behind 2008. The complete results:
Year | AL Runs | NL Runs | AL Pyth% |
1997 | 994 | 1007 | 49.4% |
1998 | 1089 | 1078 | 50.5% |
1999 | 1246 | 1374 | 45.5% |
2000 | 1278 | 1233 | 51.6% |
2001 | 1175 | 1175 | 50.0% |
2002 | 1127 | 1097 | 51.2% |
2003 | 1239 | 1267 | 49.0% |
2004 | 1252 | 1210 | 51.6% |
2005 | 1230 | 1056 | 56.9% |
2006 | 1336 | 1115 | 58.2% |
2007 | 1352 | 1172 | 56.5% |
2008 | 1249 | 1014 | 59.4% |
2009 | 1206 | 1061 | 55.8% |
2010 | 1168 | 1098 | 52.8% |
2011 | 1074 | 993 | 53.6% |
2012 | 410 | 335 | 59.1% |
Historically, the AL has won 52.3 percent of games, with the run differentials suggesting it should have won 52.9 percent of games. There's good agreement there, as we'd expect, and so it looks like the 2012 win/loss records aren't as lopsided as they should be. Over those 84 games, AL hitters have posted a .757 OPS, while NL hitters have posted a .697 OPS.
In the National League's defense, the Dodgers have played just three interleague games, and the Cardinals have played just three interleague games. But the same also goes for the Padres and the Brewers so that kind of gets canceled out. The real point in the National League's defense is: sample size. We're a third of the way through interleague play, which means we have another two-thirds of interleague play yet to go. Things could balance out, or things could even conceivably swing way in the other direction.
So we'll see where things go from here. It's too early to say anything conclusive about league superiority in 2012. According to the early indications, though, AL fans might just stay really annoying for at least another year.