OK I am going to persist with this because, well, I'm annoyed and keen to get to the bottom of it.
Stepping away from players that have in any way been edited, let's look at Dizzy Dean in the same save, which sits in the offseason at the end of 1937.
So the 1938 initial recalc has been done. This save is a 1-year recalc historical save with basically all default settings applied.
Here is how Dizzy Dean looks - scouting at 100% - ratings / real stats / editor:
So from what has been said above, Dizzy should be expected to perform as per the "expected current" output in the editor.
Those stats are miles off his historical stats for 1938. Not even close. Why would this be? Why, in a 1-year recalc historical save with almost complete default settings, wouldn't his "expected current" stats be his historical stats for the year in question, give or take a bit for variance?
While we're at it, why the regression in his CURR / POT ratings for his various pitches? That has bothered me for years.
Thanks
G