I trying out a few different settings and started a few different leagues to see what I was interested in doing.
I started a 1993 historic league, looking to see if I could manage the Braves to more than one World Series win (I chose 1993 so that Maddux is on the team). I put myself as "Manager Only", so I have no control over the roster moves - and then I intend to play out the games.
Bad luck #1 - before the regular season even began, the GM shipped off Chipper Jones (rookie year) for some 35 year old has-been.
So then I decided, how about I try a 1946 season with the Brooklyn Dodgers - with historic minors, so I could how that plays out. Same deal, Manage Only, intend to play out games...
Bad luck #2 - Before the regular season begins, the GM ships off Jackie Robinson for Joe Grace and Owen Friend - not horrible players, but...
I have also done a random debut historical where my GM drafted 22 year old Clayton Kershaw...and then traded him away after three starts.
So, I have to assume that the AI can read my mind and knows what players I am excited to have on the field - and then trades them away.