In 2013, it was the Central Division that was the talk of the National League. The Central snagged three of the NL's five playoff berths, boasting three teams with at least 90 wins. Overall, the Central was 176-154 against the NL's other divisions, getting beat somewhat by the West (78-87) but dominating the East (98-67). They also had a secret weapon: thanks to the division-by-division rotating nature of interleague play, the Central also got a bump by facing the American League's weakest division last year, the AL West (55-45).
This year, the NL Central doesn't seem to be quite as good, but it's still about as lucky. It's the AL East's turn to match up with the NL Central, and the AL East has far and away the worst run differential in the AL. The NL Central is actually one run down (-1) in interleague play so far this season, but that's more a testament to the Central's waning strength. While the Brewers have taken a step forward this season, last year's NL Central playoff teams (Cardinals, Pirates and Reds) have all taken a step back, and are a combined 95-100 (.487) after going 281-205 (.578) last season.
The NL's three divisions are now neck and neck in terms of record, all three or four games under .500. But digging under the surface in two ways, there's some evidence that it's the East that is the NL's top team.
The first is, again, interleague play. So far this season, both the AL East (-71 total run differential) and AL Central (-39) have just one team with a positive run differential. Meanwhile, the AL West is 115 runs up. That's powered in large part by the Althetics' ridiculous run differential (+130), but the rest of the division still looks favorable (-15) without them, especially considering they've played so many games against the A's. And it's the NL East that drew the short straw in interleague play this year with a matchup against the AL's top division. It may be that league-wide wild cards are not compatible with an unbalanced schedule. But it may be even less compatible with interleague play, especially now that the number of interleague games has increased from 252 to 300 games.
The second is how the NL East has fared against the other NL divisions. The East is 77-72 against the Central and West, while the Central is 59-57 against the other divisions and the West is 66-73. Run differential backs up the claim that this discrepancy is real. Through the games on June 11, the East is 59 runs over against other NL divisions, while the comparable run differentials of the Central (-12) and West (-47) are both negative.
The season is young, and the differences between the divisions are not enormous. But it's interesting that although each of the NL divisions have almost identical records, subtracting the effect of interleague play makes for a clear favorite.
Here are each NL team's run differentials against each division, as well as its record against the AL (through Wednesday's games):
|Team||AL RD||NLW RD||NLC RD||NLE RD|
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All statistics courtesy of Baseball-Reference.
Ryan P. Morrison is a featured writer at Beyond the Box Score, and co-author of Inside the 'Zona, a site on the Arizona Diamondbacks with a sabermetrics slant. You can follow him on Twitter: @InsidetheZona.