4-man, 5-man rotations
 

In what year would you suggest switching the league setting from 4-man to 5-man rotations? I spent some time on baseball-reference.com to look at the data, and it seems that by the late 60s most teams had gone to 5-man rotations, with some like the Dodgers and Orioles, sticking to 4. Is there a commonly agreed year when the transition was made? Thanks.

Was it the 60's. Or were they just starting to use a spot starter more not actually going full time with a 5-man rotation. I thought it was the 70's when they went to a 5-man rotation full time. I myself prefer to just stay with the
4-man rotations.

For the teams:
5 man came in to spare bad teams (expansion teams & others) of a bunch of 20 game losers!!!!

For the players:
You couldn't go free-agent very well with a bunch of 20's on your resume!!

The answer to the question
Bad teams early 70's
Good teams mid-70's.

Actually IIRC it was the Dodgers who were the first team to move from a 4 1/2 man rotation to a 5-man. And the last team I can remember moving away from the 4-man was another very good one: the early 80s Baltimore Orioles. As is usually the case, strategies like these are first adopted by a very good and very innovative team and then copied by everyone else in the hopes that it's akin to the Holy Grail of winning baseball games. See also: Tony LaRussa's A's in the late 80s and the complete compartmentalization of bullpens soon thereafter, platooning apparently happening after George Stallings led the Miracle Braves to a World Championship in 1914 utilizing the trick, and nobody trying to swing for the fences on every pitch until one George Herman Ruth led the Yankees up from mediocrity doing so.

If I'm simming out history (I usually do fictional historical, so YMMV), I usually go to a 5-man somewhere in the 60s. To me it produces the most realistic stats, even if that's not how it went down. Of course, OOTP produces better stats when your game becomes more like the modern one anyway.

It would be nice to have a convenient way for something to be implemented gradually rather than in a sweeping change. I know that one thing I've done is change it in the middle of the season, just to get some kind of gradual change in there.