[Syd Thrift]

One other thing I wanted to add here too is that I do fictional leagues and therefore guys who don't have set BABIPs... and man, they are volatile. I'm in mid-June in a game and watching a starter who's carrying a .205 BABIP to a 2.69 ERA (it's 1972, which was a historically low-offense season but still). For relievers, especially in partial seasons, it can be even worse: I just cut a guy who had OK peripherals but had an ERA near 9 because he'd allowed a .396(!) BABIP on the year. I just saw another guy who was seemingly blowing through the league thanks to a .098 BABIP to date through 20 or so games and 25 or so innings.

If you think OOTP's BABIPs stabilize quickly just because there's an internal number for historical sims that makes it trend up or down (which, there are mechanics for fictional/modern leagues too, they just don't tend to deviate far enough compared to real life, hence the perceived need to add this), I have sad but possibly exciting news for you. You flat out cannot make BABIP stabilize without cheating. By its nature it takes a long time to do so and as noted above relief pitchers above. The whole point of why guys like Allan Anderson and Dave Fleming crapped out after one year is that they really weren't all that good in the first place but just got hit-lucky (and as noted sequence lucky) for a year.

Again, I just want to point out that if you're doing historical leagues and want to deliberately deprive yourself of some of this knowledge, knock yourself out. I basically do this (I do have BABIP displayed because I think that, as I think I noted above, the idea that pitchers don't usually control hits on balls in play was accepted among baseball circles if not among fans going pretty far back) by not having stuff like FIP or for that matter WAR or many of the more advanced batting stats around. That can add to immersion for sure if you're trying to deliberately hamstring yourself by making a decision as to whether or not a particular player is bad or unlucky (I also highly recommend turning off ratings if/when you do this) and increase the difficulty of a game that a lot of people find to be extremely easy once you play it long enough. Just... never let it be forgotten that hamstringing yourself is exactly what you're doing here.