The devil you know: intradivisional playoff matchups in the Wild Card era

A week into the MLB playoffs, and we’re past the grinder stage, with eight teams shaking out. You’re probably aware that the Braves are one of those eight teams. You’re also probably aware that the Marlins are another (somehow). These two teams will begin their five-game clash early next week, as part of a bizarre slate: literally every Division Series on the docket features two teams from the same division (Braves-Marlins, Athletics-Astros, Rays-Yankees, Dodgers-Padres).

Honestly, the best way to describe all of this is “eh, it’s the playoffs,” and leave it at that. But that’s probably not in the interests of, well, general interest. So, to that end, check out the table below — every intradivisional playoff matchup in the Wild Card era (since 1994). Before that, though, a brief history of the MLB playoffs, just to show why this is fairly rare and why we’re only going back to 1994.

From 1903 to 1968 (except 1904, where the New York Giants refused to participate), the only real “playoffs” were comprised of a single series between the team with the best record in either league. (The “World” Series, duh.) This method stayed even as the number of teams grew to 20, which made it proportionately harder to win the pennant and earn a spot. But, really, at this point, the World Series was more of a capstone than a target, a way of settling a question about which league was superior by making the two league champions duke it out for a few games. Under this system, there were no divisions, and hence, no intradivisional playoffs.

In 1969, MLB expanded to 24 teams, and an unbalanced schedule. Meanwhile, other sports leagues were already using multi-stage playoff systems, so it was, I guess, a no-brainer for baseball to use these as well. It was even “fairer” because of the unbalanced schedule. The end prize was still a trip to the World Series, but it was no longer a contest between the two best teams, just the two teams that survived the first playoff stage. In 1981, due to a strike, baseball had its first three-tiered playoff, which went away immediately afterward. Under this system, there were also no intradivisional playoffs, because it was the two division winners that would face off in the first round.

But, in 1994, we arrived at kinda-sorta the “modern era,” where the divisions were re-aligned, and a Wild Card spot gave the best overall second-place division finisher a shot at the playoffs. The three-tiered playoffs became normal. And, intradivisional matchups finally became possible, if not common. (Also, in 2012, a bunch of Lightning Round garbage started happening, but shhhh.) Here’s what those matchups have looked like since then:

We’re only talking 17 in a quarter century, and while three years featured multiple such matchups, there was also a three-year from 2000-2002 where it didn’t occur.

Anyway, the takeaways from this are kind of... obvious? For one, the worse overall team (that is, the non-division winner) coming out ahead is not the default, but it’s also not that rare: it’s happened in six of 17 matchups. Head-to-head record between the two teams is in a similar boat — while there are two sets of teams with .500 head-to-head records that we can toss out, we get “upsets” in six of 15 series. Not common enough to be the expectation; not rare enough that it would be surprising in and of itself.

The Braves finished ahead of the Marlins (duh) but also went 6-4 against them during the regular season. That bodes pretty well, at least according to this. The Dodgers have a similar situation vis-a-vis the Padres (also 6-4 against them); the Athletics only lost three games to the Astros (7-3). The Rays, meanwhile, dominated the Yankees, going 8-2. In short, any upset in this upcoming round would be “double,” one because of team record, and one because of head-to-head record. Still, it wouldn’t exactly be a particularly rare upset if it occurred once (or multiple times); the Cubs most recently did it in 2015, toppling a 100-win Cardinals team after winning the Lightning Round earlier in the postseason, and going just 8-11 against them over the course of the year.

Historically, the Braves have won one of these intradivisional matchups (Mets, 1999, they led both in terms of overall record and head-to-head record) and lost one (Marlins, 1997, they had a poor head-to-head record against them). This matchup, on paper, is more Mets-y by these two criteria, but as we can see from above, it not matter. While randomness in a five-game series is reduced relative to a three-game set, it’s still there in large quantity. The Braves’ 6-4 record against Miami was compiled as the result of a series win, a series loss, and then winning three of four, after all. There are plenty of outcomes in there where they lose three before they win three — there are more where they don’t, and move to the NLCS — but again, nothing should be that surprising in and of itself. It’s just playoff baseball, after all.