[uruguru]

I've always been a fan of symmetrical schedules where each team in a division plays the same schedule. This is how historical leagues work, of course, until the leagues expand to 14 games (AL:1977,NL:1993).

However, it is possible to maintain symmetrical schedules with a 154-game season for pretty much any league size. The attached file is a zip of symmetrical 154-game schedules for each MLB season from 1901 (16 total teams) to 2025 (30 total teams). For years with identical structures (e.g 1901-1960), the team IDs are shuffled so the schedules vary each year.

Details about the schedules
154 games over 25 weeks (175 days)
Start day should be first Monday on/after April 3rd.
Symmetrical schedules for division rivals
5-day All-Star Break in Week 15
Each team has 12 weekend homestands
No Doubleheaders
No Interleague games

How they work, by league size
8 teams - 1 division, 22 games vs each division rival. This was the AL until 1961, and the NL until 1962
10 teams - 2 divisions, 5 teams each. 26 games vs each division rival, 10 games vs other teams.
12 teams - 2 divisions, 6 teams each. 26 games vs each division rival, 4 games vs other teams.
14 teams - 2 divisions, 7 teams each. 14 games vs each division rival, 10 games vs other teams.
16 teams - 2 divisions, 8 teams each. No inter-divisional games. 22 games vs each division rival.


How the MLB will need to be restructured within OOTP to use these symmetrical schedules
1901-1960 : Each league has 8 teams. No change necessary.
1961: AL expands to 10 teams. AL must be restructured into two 5-team divisions.
1962-1968: Both leagues have 10 teams. AL & NL must be restructured into two 5-team divisions.
1969-1976: Both leagues have 12 teams. No change necessary.
1977-1992: AL has 14 teams, NL has 12 teams. No change necessary.
1993: Both leagues have 14 teams. No change necessary.
1994-1997: Both AL & NL switch to 3 divisions. Both must be restructured back to two 7-team division.
1998-2012: NL expands to 16 teams. Both leagues need to be restricted back to two divisions.
2013-present: Houston forced to AL because reasons. Need to revert to 14/16 structure with two divisions.

I'm going to experiment with creating some files that will restructure the league automatically for each division. I'm not sure if it can be done, but if it can I'll add it here.