MLB Interdivision Records Since 2013 Realignment

We’ve spent some time on this site outlining how bad the Central Divisions are right now, and we do stand by that. But it’s more historically unusual than we realized. Or rather, the NL Central being this bad is more unusual than we realized. The AL Central has been bad for a while.

Since the Astros moved to the American League, prior to the 2013 season, the NL Central has actually been the best in baseball in interdivision games against teams of their own league (we limited the examination thusly because 1- the schedule became much more even beginning in 2013 and 2- that evenness doesn’t extend to interleague games). Within the NL, the numbers look like this:

Within the AL, they look like this:

These win percentages might not look like much, but a .525 win percentage is an 85-win season, and a .468 win percentage is roughly a 76-win season, and this sample is coming from eight full seasons of baseball. The NL Central has, for the last eight years, been pretty good. The AL Central has, for the last eight years, been very bad.

Even last year, the NL Central posted a winning record in interdivision, intraleague games. The division may have peaked in 2015, when the Cardinals, Pirates, and Cubs each won upwards of 95 games, but it’s remained competitive since, while the NL East has quietly failed to beat either of its counterparts over the course of a full season since it beat the Central 85 to 80 in 2016. This, despite NL East teams winning two World Series in the last three years.

The AL Central doesn’t have a streak like the NL East’s to point to—in 2017, the AL Central eked out 83 wins against 82 losses in games against both the AL East and the AL West—but they do have the most woeful individual season against a rival division, going 51-114 against the AL West in 2018.

I don’t know exactly what to make of it. Part of our point about the National League’s struggles has been to highlight the wisdom of eight-team divisions when expansion rolls around, but adding the Pirates to the NL East might risk amplify existing disparities, even with the addition of the Reds and the Montréal Rays (the most likely realignment/expansion scenario, right now, seems to be a new AL franchise in Nashville, a new NL franchise in Portland, the Rays moving to Montréaland flipping to the NL, the A’s moving to Las Vegas, and someone from the NL flipping to the AL—most believably the Brewers, for whom such a move would be a return to the olden days).

At the same time, though, maybe this will all change. At least on the NL side. The NL East is having a good year. The NL Central is having a bad year. In the AL, as is tradition, the Central is struggling and the East is good. Thankfully, with the schedule changing next year—MLB is replacing two series against each division opponent with one series against each interleague opponent, making each franchise play each of the other 29 at least once annually—things will only get clearer. 2020, paradoxically, highlighted some Central Division ineptitude when all seven playoff teams from the Centrals lost the Wild Card Series, with five of the seven swept. 2023 and other short-term-future seasons might expose things further, perhaps with a losing-record division champion.

Here are the head-to-head, division-vs-division records for each of the last eight full seasons, in order from biggest mismatch to most competitive: