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 games — 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.

Who gains (and loses) the most in a shorter season? MLB teams by playoff berths and World Series titles gained or lost in 1,000 simulations each of a standard, 162-game season vs. a 102-game season PLAYOFF BERTHS WORLD SERIES TITLES Team 162 games 102 Games Diff. 162 games 102 games Diff. Chicago White Sox 109 187 +78 2 2 0 Cleveland Indians 387 457 +70 16 20 +4 Chicago Cubs 211 264 +53 5 8 +3 Pittsburgh Pirates 139 177 +38 4 4 0 Kansas City Royals 7 40 +33 0 0 0 Cincinnati Reds 289 321 +32 8 10 +2 Milwaukee Brewers 35 64 +29 0 0 0 Boston Red Sox 186 210 +24 3 2 -1 Toronto Blue Jays 173 196 +23 4 5 +1 Miami Marlins 4 23 +19 0 0 0 San Diego Padres 362 381 +19 9 16 +7 Colorado Rockies 91 108 +17 0 2 +2 New York Mets 327 339 +12 11 14 +3 Texas Rangers 30 41 +11 0 0 0 Arizona Diamondbacks 106 112 +6 3 1 -2 Seattle Mariners 4 9 +5 0 0 0 Detroit Tigers 0 5 +5 0 0 0 Philadelphia Phillies 198 202 +4 7 2 -5 Baltimore Orioles 0 3 +3 0 0 0 San Francisco Giants 27 28 +1 0 0 0 Tampa Bay Rays 607 608 +1 27 31 +4 New York Yankees 600 593 -7 44 45 +1 Los Angeles Dodgers 994 980 -14 336 320 -16 Oakland Athletics 390 370 -20 17 16 -1 St. Louis Cardinals 705 669 -36 67 63 -4 Los Angeles Angels 746 708 -38 64 77 +13 Minnesota Twins 855 789 -66 77 86 +9 Atlanta Braves 933 845 -88 141 141 0 Washington Nationals 579 487 -92 43 45 +2 Houston Astros 906 784 -122 112 90 -22 Source: Out of the Park Developments

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.

Everybody’s playoff odds get better with more teams MLB teams by playoff berths and World Series titles gained or lost in 1,000 simulations of a 102-game season with a standard, 10-team playoff vs. a 14-team playoff with a three-game wild-card round PLAYOFF BERTHS WORLD SERIES TITLES Team 10-team playoff 14-team playoff Diff. 10-team playoff 14-team playoff Diff. Oakland Athletics 370 593 +223 16 23 7 San Diego Padres 381 592 +211 16 28 12 Cleveland Indians 457 666 +209 20 17 -3 New York Mets 339 548 +209 14 13 -1 Chicago Cubs 264 467 +203 8 12 4 Toronto Blue Jays 196 395 +199 5 2 -3 New York Yankees 593 791 +198 45 38 -7 Washington Nationals 487 679 +192 45 43 -2 Boston Red Sox 210 396 +186 2 3 1 Philadelphia Phillies 202 381 +179 2 11 9 Los Angeles Angels 708 881 +173 77 62 -15 Chicago White Sox 187 355 +168 2 5 3 Cincinnati Reds 321 484 +163 10 9 -1 Tampa Bay Rays 608 767 +159 31 36 5 Colorado Rockies 108 267 +159 2 9 7 Pittsburgh Pirates 177 323 +146 4 6 2 Arizona Diamondbacks 112 258 +146 1 8 7 Minnesota Twins 789 922 +133 86 71 -15 Houston Astros 784 912 +128 90 106 16 St. Louis Cardinals 669 786 +117 63 39 -24 Texas Rangers 41 139 +98 0 1 1 Atlanta Braves 845 934 +89 141 142 1 San Francisco Giants 28 111 +83 0 2 2 Kansas City Royals 40 121 +81 0 1 1 Milwaukee Brewers 64 120 +56 0 0 0 Seattle Mariners 9 39 +30 0 0 0 Miami Marlins 23 53 +30 0 1 1 Los Angeles Dodgers 980 997 +17 320 312 -8 Detroit Tigers 5 16 +11 0 0 0 Baltimore Orioles 3 7 +4 0 0 0 Source: Out of the Park Developments

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.

Fewer games but more playoff teams increases parity MLB teams by playoff berths and World Series titles in 1,000 simulations of a 102-game season with a 14-team playoff and a three-game wild-card round, compared with a standard season and playoffs PLAYOFF BERTHS WORLD SERIES TITLES Team Short season, expanded playoffs Diff. from stand. season Short season, expanded playoffs Diff. from stand. season Cleveland Indians 666 +279 17 +1 Chicago Cubs 467 +256 12 +7 Chicago White Sox 355 +246 5 +3 San Diego Padres 592 +230 28 +19 Toronto Blue Jays 395 +222 2 -2 New York Mets 548 +221 13 +2 Boston Red Sox 396 +210 3 0 Oakland Athletics 593 +203 23 +6 Cincinnati Reds 484 +195 9 +1 New York Yankees 791 +191 38 -6 Pittsburgh Pirates 323 +184 6 +2 Philadelphia Phillies 381 +183 11 +4 Colorado Rockies 267 +176 9 +9 Tampa Bay Rays 767 +160 36 +9 Arizona Diamondbacks 258 +152 8 +5 Los Angeles Angels 881 +135 62 -2 Kansas City Royals 121 +114 1 +1 Texas Rangers 139 +109 1 +1 Washington Nationals 679 +100 43 0 Milwaukee Brewers 120 +85 0 0 San Francisco Giants 111 +84 2 +2 St. Louis Cardinals 786 +81 39 -28 Minnesota Twins 922 +67 71 -6 Miami Marlins 53 +49 1 +1 Seattle Mariners 39 +35 0 0 Detroit Tigers 16 +16 0 0 Baltimore Orioles 7 +7 0 0 Houston Astros 912 +6 106 -6 Los Angeles Dodgers 997 +3 312 -24 Atlanta Braves 934 +1 142 +1 Source: Out of the Park Developments

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.”