Winners And Losers In MLB’s New Playoff Format


Earlier this week, we released our MLB predictions to reflect each team’s chances during this year’s shortened, 60-game schedule. But it wouldn’t be baseball in 2020 without one last curveball before first pitch. In an eleventh-hour amendment to the 2020 season’s structure, the owners and players union agreed on Thursday to expand the postseason from the usual 10 teams to 16. The playoffs will include every division’s first- and second-place teams, along with two extra wild cards from each league.

My colleague Jay Boice has crunched the numbers, and we’ve updated our MLB predictions interactive to reflect baseball’s new postseason reality. So whose odds changed the most? Well, the expanded playoff system has altered the overall World Series picture some: The Dodgers — aka the best team in baseball — were the biggest movers, losing almost 3 percentage points of championship probability (still leaving them at an MLB-best 19 percent going into the season). The Astros and Yankees each lost nearly 1 percentage point, and everyone else gained or lost less than two-thirds of a percentage point apiece:

Which teams gained or lost the most title probability?

Largest gains or losses in 2020 championship probability — according to the FiveThirtyEight model — for teams whose odds moved by at least +/-0.2 percentage points under MLB’s new postseason format

Moving up Championship Probability
Team Division Before After Diff.
Red Sox AL East 1.5% 2.0% +0.6
Diamondbacks NL West 1.5 2.0 +0.5
Athletics AL West 3.0 3.4 +0.4
Cubs NL Central 2.9 3.2 +0.3
Cardinals NL Central 2.0 2.3 +0.3
Angels AL West 1.0 1.3 +0.3
Rockies NL West 0.5 0.7 +0.3
Rays AL East 4.9 5.2 +0.3
Braves NL East 3.0 3.3 +0.3
Mets NL East 3.4 3.6 +0.3
Brewers NL Central 2.6 2.9 +0.2
White Sox AL Central 1.0 1.2 +0.2
Rangers AL West 0.4 0.6 +0.2
Phillies NL East 1.1 1.3 +0.2
Blue Jays AL East 0.3 0.5 +0.2
Padres NL West 1.2 1.4 +0.2
Moving down Championship Probability
Team Division Before After Diff.
Nationals NL East 6.5% 6.4% -0.2
Twins AL Central 6.6 6.4 -0.2
Yankees AL East 14.4 13.6 -0.8
Astros AL West 13.4 12.5 -0.9
Dodgers NL West 21.7 18.9 -2.8

Predictions as of July 24, 2020.

These swings boil down to the extra postseason series that top teams will have to play, even if they win their divisions. Nearly as important, the new system also reduces the odds that any reasonably talented team will miss the playoffs — meaning the playoffs will include more teams that are legitimate threats to pull off upsets.

Among teams that gained the most postseason probability,1 the biggest beneficiaries weren’t the top teams — L.A.’s playoff odds went up by only 9 percentage points, second-fewest of any club. Rather, the big winners were the good-but-not-great teams that could still potentially make noise if they get in the field. The Boston Red Sox, for all of their problems, picked up 30 points of playoff probability under the new system. The Chicago White Sox went from just a 27 percent playoff probability under the old system to over 57 percent now, another increase of around 30 points. The Athletics, Angels, Rays, Diamondbacks, Indians and Braves all got boosts of at least 25 percentage points.

The common theme: The teams helped the most were those that looked pretty solid on paper but weren’t especially likely to win their divisions or even take one of the old wild-card slots. The expanded postseason has given them another path to make the playoffs — and a chance to create havoc once there.

Whose playoff outlook got brighter?

Largest gains in 2020 playoff probability — according to the FiveThirtyEight model — under MLB’s new postseason format, for teams with a current playoff probability of at least 25 percent

Playoff Probability
Team Division Before After Diff.
Red Sox AL East 29.9% 60.2% +30.4
White Sox AL Central 27.4 57.6 +30.2
Athletics AL West 45.3 73.6 +28.4
Angels AL West 22.7 50.7 +28.0
Rays AL East 54.6 81.3 +26.7
Diamondbacks NL West 28.9 55.3 +26.3
Indians AL Central 54.6 80.8 +26.2
Braves NL East 39.5 64.9 +25.4
Padres NL West 25.6 50.3 +24.7
Mets NL East 42.3 66.5 +24.2
Reds NL Central 42.6 66.7 +24.2
Cubs NL Central 43.1 66.8 +23.7
Brewers NL Central 39.6 63.3 +23.6
Cardinals NL Central 38.6 62.2 +23.6
Rangers AL West 14.8 37.3 +22.6
Phillies NL East 22.8 45.2 +22.3
Nationals NL East 57.3 78.9 +21.5
Blue Jays AL East 13.0 34.2 +21.3
Twins AL Central 66.9 87.9 +21.0
Rockies NL West 15.6 36.3 +20.7
Astros AL West 76.5 92.5 +16.0
Yankees AL East 81.6 94.5 +12.9
Dodgers NL West 87.4 96.0 +8.6

Predictions as of July 24, 2020.

The change in format also filters into the odds of making subsequent rounds: The Red Sox, D-backs and Angels are also the teams whose odds of making the division series (the “Elite Eight” of this bracket) went up the most; the Dodgers, Yankees, Astros and Twins all saw their division series odds go down by at least 8 percentage points apiece.2 A similar story goes for making the league championship series and even the World Series — MLB’s middle class got a boost, while the elite teams took a hit.

The old theory that a team’s primary job is to simply make the playoffs — and ride the wave of randomness after they arrive — might be truer now than ever before, even as 53 percent of teams will now punch a postseason ticket. Our model thinks the new format will have a leveling effect, pulling the top teams slightly down and giving a bonus to those clubs who would have been at the fringe of the playoff picture under the old system but still have enough talent to make things interesting in a postseason series.

Although the overall effect wasn’t enough to keep the Dodgers, Yankees and Astros from staying World Series favorites, their odds have dropped by a not-insignificant amount. That should add an extra element of uncertainty to the 2020 season. Because, hey, apparently we didn’t already have enough chaos in this strange, short, pandemic-marred campaign.

Jay Boice contributed research.