How Much Damage Did MLB Teams Do to Their Playoff Odds in One Weekend?

Baseball is a sport made for large numbers. It’s predicated on “We’ll get ’em next time” and occasionally its darker cousin: “Oh, no, not again.” Because MLB teams play almost twice as many games per year as their next closest major-league counterparts, you can understand the shape of a team’s season only by examining dozens of games; thousands of plate appearances; and tens of thousands of individual pitches. To truly know a baseball team is to be positively immured in data, like the dirty cop in Witness who gets buried in the corn silo. And even that’s not enough sometimes.

So it’s important not to get carried away with one weekend’s results. In Monday’s column about immediate reactions from MLB’s opening weekend, I tentatively identified the Phillies’ sweep of Atlanta as a bellwether, fully aware that the same thing happened in 2019, when the Braves went on to win the division and the Phillies finished 16 games back. Or consider the 2018 Mets, who started the season 11-1 and finished 77-85. Obviously it’s too early to tout the Orioles as the new AL East favorites or start hemming and hawing about the Braves, but while these games are but a trivial fraction of a 162-game season, they still count.

So for teams that anticipate being in a close pennant race this year, how much damage can three or four games do?

Quite a lot, as it turns out. According to FanGraphs, nine teams saw their playoff odds move up or down by five or more percentage points after the first series of the season.

Every statistical process is the product of the assumptions and methodology, and playoff odds this early in the season rely heavily on preseason computer projections; as more data rolls in, the projections get better. In short, caveats abound.

But as a former professor of mine used to say: All models are wrong, but some models are useful. So what can we learn from this group of nine teams?

Well, the first thing to note is who’s not on this list. Of the teams that came into the season with a playoff percentage above 61 percent or a projected win total higher than 90, only the Astros’ odds shifted enough to be featured on that table. The Dodgers and Padres both went 3-1 last weekend and their chances barely moved. They’re merely performing as expected. The Orioles, who went 3-0, also moved by just a tenth of a percent. On opening day, FanGraphs’ projection systems had them pegged for about 65 wins, nowhere near enough to make the playoffs. Now they’re projected to win 67 games, which is, again, nowhere near enough to make the playoffs. A difference of two expected wins doesn’t matter at that end of the standings.

But for teams projected to win between 80 and 90 games, two wins could make or break a season. In eight MLB seasons under the current playoff structure, no team has made the postseason while winning fewer than 85 regular-season games, and 74 of 80 playoff teams have won at least 88. Conversely, no team that’s won more than 93 games has missed the playoffs in that time, and only 4 percent of non-playoff teams have won 88 games or more. With two wild-card berths per league, a team that wins at least 87 games will probably make the playoffs, and a team that wins 86 or fewer will probably go home early.

The postseason cutoff point has actually been a few wins higher than 87 in the past few years, but the principle remains the same: Teams projected to be on the playoff bubble can see their odds move significantly, even this early in the year.

The other thing that stands out from the season’s early returns: Eight of the nine teams that moved more than 5 percentage points in playoff odds played a division rival over the weekend. Five of those eight teams either swept their series or were swept themselves. Oakland in particular merits special mention. The A’s entered the season as underdogs in the AL West to the Astros, with about a one in six chance of winning the division and one in three of making the playoffs, according to FanGraphs. Very much in the mix, but in need of a few breaks.

The A’s have made the playoffs in each of the past three seasons, and a big part of their success has been their ability to hold their own against Houston. Between 2018 and 2020, the A’s went 22-26 against the Astros, which doesn’t look great on paper, but is actually the fourth-best winning percentage of any AL team against Houston during that span. No AL team was more than two games over .500 against the Astros through those three seasons, and no other AL West team was within 12 games of .500 against Houston. In order to keep pace with the Astros this year, the A’s need to basically break even head-to-head.

That will be tough now, after they dumped four in a row at home. And I do mean dumped—the aggregate score of those games was 35-9. Meanwhile another AL West rival, the Angels, took three of four from the White Sox, while the Blue Jays—a competitor for the wild card—won a series against the Yankees in New York.

Yes, it’s early, and the A’s have plenty of time to recover. But it’s a body blow; if that happened in late August, at least one local newspaper would put the Grim Reaper on the front page in an Astros hat. Oakland’s opening weekend struggles bring to mind the old truism about how you can’t win the pennant in April, but you can lose it. Ditto the Red Sox, who were long shots for the AL wild card a week ago; after being swept by Baltimore, their playoff odds have gone from discouraging to remote.

In both of those cases, there’s no use revisiting the site of the disaster to indulge regrets. When you get outscored by six runs a game over a series, the best thing to do is burn the game film, put it in a lead-lined box, and bury it in an EPA-approved disposal location. The Braves, meanwhile, held the Phillies to just nine runs total last weekend, but lost three close games because they ran into three very good, very hot starting pitchers. It happens.

But sometimes the margins are thinner. Consider the White Sox, whose playoff odds suffered only a 2.5 percentage-point drop after they went 1-3 in Anaheim, while the Twins and Blue Jays won their respective series. All four Chicago starters this past weekend left the game either tied or leading, and the bullpen—considered to be one of the team’s strengths—coughed up three of those four games.

It’s easy to write that off as anomalous, as Evan Marshall, Aaron Bummer, and Codi Heuer were all outstanding last year and should be again in 2021. But the team—more specifically, manager Tony La Russa—made some preventable errors: failing to challenge a borderline call in a one-run game on Opening Day; letting Billy Hamilton hit for himself while down a run on one of the team’s last four outs; and letting Matt Foster lose that game an inning later while superstar closer Liam Hendriks sat idle in the bullpen.

These are small errors, but they add up, even this early in the season. After that series against the Angels, FanGraphs had the White Sox projected to win 85 games. If they’d banked two extra wins this weekend, they could be in line for 87. Remember how things go in the 10-team playoff era. Usually, 87-win teams make the playoffs; 85-win teams don’t.