A Shortened MLB Season Favors The Underdogs — But An Expanded Playoff Helps The Favorites

When and if the Major League Baseball season begins — whether in May in fanless Arizona stadiums or at some other point — it may come with a completely different playoff format. Even before the COVID-19 pandemic halted play, the sport was mulling a postseason expansion from 10 teams to 14 for the 2022 season, but the players agreed to the possibility of an immediate change this year as part of a short-term labor deal. “I don’t know if I would say most players are on board with (an expanded playoff), but I’d at least say players are willing to make the concession for this year,” Pittsburgh Pirates pitcher and players union representative Jameson Taillon told FiveThirtyEight. “I will be interested to see how it plays out, if it plays out.”

Adding teams to the playoffs could garner additional revenue through more televised games and perhaps gate receipts if it’s deemed safe to allow fans back into ballparks, which would help reduce the economic strain of the coronavirus-shortened season. But an expanded postseason, coupled with that abbreviated regular season, could also dramatically change the fortunes of many teams. To gain a sense of who would be the winners and losers of such a format change, FiveThirtyEight enlisted the help of our friends at Out of the Park Developments to simulate different scenarios.

To see the effects of a different playoff system, we first had to account for how a shortened season might change who would make the postseason under the current format. As a control group, OOTP ran 1,000 simulations of a 162-game 2020 season with the standard 10 playoff teams and counted the number of times each team made the playoffs. Rosters were set as of March 29, reflecting season-ending injuries to stars including Chris Sale and Noah Syndergaard. OOTP then ran 1,000 simulations of a shortened regular season — we settled on 102 games¹ — with the same standard, 10-team postseason. We compared the two simulations to see how many more or fewer times a team made the playoffs in the shortened season compared to the regular season.

The randomness added by shrinking the season seems like it would hurt the best teams and help those a tier below. In our condensed regular-season simulations, with a typical postseason format, the Chicago White Sox, Cleveland Indians and Chicago Cubs were the greatest gainers in playoff berths, while the biggest losers were the Houston Astros, Washington Nationals and Atlanta Braves. The Astros and Braves were still among the top four teams most likely to make the playoffs, and the Cubs and White Sox would still face long odds, but the elites and everyone else moved closer together in a shorter season.

After establishing a short-season baseline, we then looked at the differences in outcomes generated by playoff formats. The scenario under consideration for 2022 was a 14-team playoff with a best-of-three wild-card round. That setup would see each league’s three division winners advance to the playoffs along with four wild cards from each league. The team with the best record in each league would receive a first-round bye, while the 12 other teams would begin the playoffs in a best-of-three series.

The expanded field, predictably, gave every team a better shot at making the playoffs. The Cubs and Indians were again among the greatest beneficiaries, joined by the Oakland A’s, San Diego Padres and New York Mets in gaining at least 200 postseason berths per 1,000 simulations from the 10-team setup. The Astros, which had lost 122 playoff berths per 1,000 simulations in the switch from a 162-game season to 102 games, gained all of that back and then some with the added playoff teams.

Once teams made the playoffs in this different format, how did they do? In these simulations, the Houston Astros were the big winner, gaining 16 World Series titles over a short season with a standard 10-team playoff. The Padres saw 12 additional titles, while the Philadelphia Phillies added nine, and the A’s, Colorado Rockies and Arizona Diamondbacks gained seven each.

No team advanced less often to an expanded postseason, but some did win fewer World Series. The St. Louis Cardinals lost 24 titles per 1,000 simulations, while the Twins and Angels saw 15 fewer titles each, and the Dodgers dropped eight. But the Dodgers still dominated the simulated title totals, with 312 championships in the 1,000 simulations. The Braves (142) and Astros (106) were the other two most likely champions, and those three teams combined for slightly more titles — nine — in the 14-team playoff than they did in the 10-team format. While expanding the playoff could further promote parity in a shortened season as it widens the field, the best teams in each league would also benefit from the lone first-round bye in such a format.

The final comparison was between the standard 162-game season and the shortened season with a 14-team playoff format. The Indians, Cubs, White Sox, Padres, Blue Jays, Mets and A’s gained the most playoff berths, with the Boston Red Sox also enjoying a 20 percentage point jump in playoff berths.

The Padres added the most World Series championships overall with 19, followed by the Rockies and Rays at nine each and the Cubs at seven. The Cardinals (-28) and Dodgers (-24) were the only double-digit decliners between the simulations.

An interesting change from a normal season to a much different one was that the greatest gainers included a number of clubs that have young and promising cores (the Jays, Rays and Padres) and clubs that made significant offseason additions — like the White Sox, who signed Yasmani Grandal, and the Angels, who gave Mike Trout the best teammate he’s ever had in Anthony Rendon. We wondered in December if such signings would make baseball more competitive; an expanded playoff field would perhaps benefit those teams that tried to improve this winter and serve as a disincentive to tanking.

MLB decision makers will have to weigh the cost of watering down the regular season (with more teams making the playoffs) versus the benefits of an expanded postseason. It’s an experiment that could inform long-term decisions on the playoff format. And it’s worth noting that playoff fields rarely shrink in professional sports.

“There’s something special about really earning that spot,” Taillon said about the traditional postseason format. “At the same time, people want to see baseball. Having more teams in the playoffs is a way for more people to get their eyes on the game.”