I always subtract at least 150 pts of OPS from Memphis hitters making the jump to the majors. That would put Crooks in the .620 OPS range. His actual was .396, which was even worse.
This was an interesting comment and I wanted to drop it into some real stats before I commented. I looked up our current “regulars”-meaning the top 12 players by PA from this past year. I’d think we would agree that these guys constitute the core of the position side of the roster for 2025. Here are their AAA OPS vs MLB OPS side by side:
Player AAA OPS/MLB OPS/Diff
Herrera 0.874/ 0.806/ -0.068
Pages 0.667/ 0.643/ -0.024
Contreras 0.961/0.811/ -0.15
Donovan 0.867/ 0.772/ -0.095
Winn 0.838/ 0.68/ -0.158
Arenado 0.999/ 0.846/ -0.153
Nootbaar 0.878/ 0.747/ -0.131
Scott 0.597/ 0.576/ -0.021
Walker 0.745/ 0.68/ -0.065
Burleson 0.842/ 0.742/ -0.1
Gorman 0.821/ 0.719/ -0.102
Saggese 0.762/ 0.625/ -0.137
It looks like the majority of them don’t meet your “at least 150 pts of OPS” test, yet all of them showed a drop in OPS in their major league careers from their AAA stats. Of course, the hitting environment matters. Not all of them came up in the St Louis system, but for the ones who did, the hitting environments in St Louis vs Memphis are a bit different. Using fangraphs’ wRC+, an “average” hitter in St Louis this year would have about a .690 OPS, while an “average” hitter in Memphis would have about a .770 OPS, for an 80 point difference. So the actual drop in offensive performance would be a little less. Of course, this isn’t a perfect analysis. I found this article stating that the jump from AAA to MLB results in about a 25 point drop in wRC+, which of course isn’t universal, but it’s a good average.
Bottom line, I would probably adjust to about a 100 point OPS drop and think about a guy shedding anywhere from 10-25 points of wRC+ on the move. Some will be more and some less, but it’s probably not fair to expect any prospect to do much better than their minor league stats (to be fair, some notable names have done just that). I’d guess that the guys who “make it” and have longer big league careers skew closer to the 10 point loss, while the guys who do more poorly and flame out probably push past the 25 point loss. For Jimmy Crooks, that means he’s probably looking at a .680 OPS line (which is about average in St Louis’ environment) and a 90-100 wRC+. That’s fine, if he’s also playing good defense at catcher. That’s probably a slightly sunny projection. Realistically, he could well be looking at anywhere from being a 75 wRC+ guy (nearly unplayable without elite glove) to 105 wRC+ and it wouldn’t be a real shocker.