[Reed]

It take me 2-3 hours to set up a random league but I like the results.
Start regular historic league in 1895.
Under historical tab set for random debut 1896-1900 (will explain why later).
Turn injuries off for now.
UNCLICK players miss season according to history and UNCLICK players retire according to history.
Turn development on (I use combination 3 yr recalc and development).
Under rules tab set rookie draft for 10 rounds. There were about 310 players that debut between 1896-1900 or just over 19 draft rounds. With 10 round rookie draft all those players will be drafted in 2 years or by the end of 1896.
Spring 1897 under historical tab change random debut years to 1901-present.
Under rules change draft rounds to 6 or whatever you normally use.

Spring 1900 is my busy time and takes a couple hours.
Go through and delete all players (over 100) from league that DID NOT play IRL in 1901 or later! Some teams might be short of players after deleting so many so I release all player and let AI do an inaugural draft. Should have about 500 players available
Go into league functions and delete/reset ALL 8 tabs on bottom left (service time, injuries, league history, etc.).
I generally use 1984 as my base year for stats so go in stats & AI tab and on left side set 1984 as my year, go to day before opening day and set 1984, go through and uncheck the automatic update things.
Fast sim to end of year and check stats to make sure it looks reasonable.

Go to spring 1901. At this time my league will have all the players that played in 1901 that are in their prime or are about to retire or missed 1901 due to injury IRL but showed up a year or 2 later (Jimmy Ryan, Dan Brothers, etc.). My league also has almost 400 youngsters (or just entering their prime) that debut IRL 1901-present.
I again go into league functions and delete ALL 8 items on bottom left.
Not necessary but I usually release all players and do an inaugural draft.
I make sure my schedule is correct.
Set injury setting to whatever.
Go to day before opening day, set 1984 for modifiers and off we go.
This way I have Wagner, Lajoie or Waddell being league leaders with a young Willie Mays or Lou Brock. It is a little weird to see Charlie Hickman or Mike Donlin lead the league in Home Runs for a couple years.
The only thing that seems weird to me is Pete Dowling often gets 4 or 5 cy Young awards before he retires and sometimes he doesn’t do anything. I admit that if he is playing lights out after a couple seasons, I go into his editor and change his ratings. That’s the only player I modify.
Anyway, that is basically how I start out. I may have missed 1 or 2 minor steps.