MLB expansion: How a 32-team league might work

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When MLB expansion comes up, which cities will get new teams is always the first topic. But there's another factor that will impact the entire sport: How will MLB realign its divisions -- and structure its playoffs -- to accommodate those new franchises.

How much could this matter? Look no further than one of the biggest stories of the 2023 season: the emergence of the Arizona Diamondbacks. Given a different context, one in place only a couple of years before, few may have noticed.

The 84-win Diamondbacks squeezed into the playoffs during the final week of the season, landing the National League's No. 6 seed, and parlayed that opportunity into a World Series berth. They were an exciting, emergent team that turned into one of baseball's great Cinderella stories.

Now consider how baseball's current format abetted Arizona's run:

Schedule: One of the teams the Diamondbacks held off for that last slot was division rival San Diego Padres, who they last played on Aug. 19. The Padres wound up two games back of Arizona in the standings. In 2022, under the previous scheduling formula, the teams clashed seven times after that date.

Divisional alignment: Arizona finished second in the NL West and sixth in the NL as a whole. If the D-backs had been in the AL West, they would have finished fourth in their division and eighth in the league standings, out of the running.

Playoff structure: The Diamondbacks became the second straight No. 6 seed to win an NL pennant. Before 2022, there was no such thing as a 6-seed in baseball, save for the ad hoc playoffs after the pandemic-shortened 2020 season.

None of this is to decry Arizona's memorable postseason run. Nevertheless, the reality remains that the choices baseball makes in the way it formats itself is intrinsically tied to the way we experience and remember each campaign.

We've been discussing future expansion lately and when it comes to format, one thing we know for sure is that it will change. Expansion is always accompanied by a structural makeover of some kind, whether it's season length (1961, 1962), divisional structure and/or assignments (1969, 1998), or the schedule formula (all expansions, if only to accommodate the new teams).

So when baseball moves to 32 teams, how will the format change to accommodate the growth? How will the key structural elements -- schedule, league/division assignments, playoff format -- inform baseball's future narratives?

We don't have an ironclad timeline for expansion, and while we've tried to narrow the list of candidate cities to a fairly small pool, we don't know which cities will land teams. We also don't know where the 30 existing franchises will be playing by the time expansion occurs.

With so many moving parts, it's impossible to pinpoint what the future looks like for baseball's format. However, after examining the topic and consulting with industry experts, we can point out some of the factors that will come into play, how we might evaluate those factors through the prism of the seasons to come until expansion becomes a reality and look at one possible way it could all come together.