This seems like a simple question that someone must know the answer too, or it was discussed before in a thread and I could be pointed to.
Perhaps a visual representation. This is a New 1970 Import using the Wizard with 1 year Recalc with Real Stats. Any adjustments in the Wiz were minor, like using the 1-100 Scale rather than the 20-80 scale (old habit that's impossible to break).
First image is Steve Carlton in the game. I scrolled down on my screen so that Career could be shown, which worked nicely as the famed 1972 is the first Season shown and easy to see.
Second is his Fangraphs page.
Fangraphs - Steve Carlton
Can someone jump in? Both FIP and FIP- are off. I actually find value in FIP- as a useful shorthand when looking at non-obvious players rather than the Carlton, Ryan, Blyleven, Seavers of the world. Hence the examples of Torrez & Splittorff in the first post.
2.01 Fangraphs in 1972 --> 2.74 in OOTP 1972 is a pretty massive variance for what is a pretty simple math equation.