Here are the stats for two players, as independent as we can easily get them.
No Wins, no Losses - too dependent on team.
No Saves, GS, or GP - too dependent on coach usage.
These are the stats that I think best represent the effectiveness of the pitcher. Ideally, we could control for the defense behind the pitcher and the home park, among other things, but the quick-and-dirty is perhaps the best we can easily do given the stats provided by WhatIf.
Red = Average or Worse
Orange = Good/Very Good, but not Great and/or under 145IP.
Green = Great Season with 145IP+
Player A had 7 "Great" seasons.
Player B had 6 "Great" seasons.
Player A had 5 "Good/Very Good" seasons of significant (100+) IP, plus 1 "Good/Very Good" lower-IP season.
Player B had 8 "Good/Very Good" seasons of significant (100+) IP, plus 1 "Good/Very Good" lower-IP season.
Player A had 1 "Average or Worse" season of significant (100+) IP, plus 2 "Average or Worse" lower-IP seasons.
Player B had 0 "Average or Worse" seasons of significant (100+) IP, plus 2 "Average or Worse" lower-IP seasons.
Let's focus on those "Great" seasons, but not on the W/L from them. Instead, we're going to judge effectiveness on the mound by ranking ERA, WHIP, OAV, OBP, and SLG against. A top 3 finish is in bold.
In the 13 "Great" seasons, here are the ERA rankings:
Player A - #3, #4, #6, #7, #8, #9, #10
Player B - #1, #2, #5, #11, #12, #13
In the 13 "Great" seasons, here are the WHIP rankings:
Player A - #1, #2, #4, T-#5, #8, T-#9, T-#9
Player B - #3, T-#5, T-#5, T-#9, T-#9, #13
In the 13 "Great" seasons, here are the OAV rankings:
Player A - #3, #6, #9, #10, #11, #12, #13
Player B - #1, #2, #4, #5, #7, #8
In the 13 "Great" seasons, here are the OBP rankings:
Player A - #1, #2, #6, #7, #9, #10, #13
Player B - #3, #4, #5, #8, #11, #12
In the 13 "Great" seasons, here are the SLG against rankings:
Player A - #4, #6, #7, #9, #10, #11, #12
Player B - #1, #2, #3, #5, #8, #13
In case you were unsure, Player A is a 4-time Cy Young winner and perhaps a lock for the HOF - Bartolo Escobar.
Player B is a 1-time Cy Young winner and probably not going to make it - Zack Damon. This is not because he was any less effective as a pitcher over his career, or any less dominant at his peak, but instead because he had the misfortune of being a middle reliever rather than a starter and so did not accumulate enough wins or awards. I feel some responsibility for this as his owner for 3 seasons.
During those 3 years he was 46-14, but it was the third season - which was not the best of the 3 (his Cy Young and best season was the first of the 3) - where I used him in such a fashion as to allow his W/L to reflect his abilities at the expense of saves. He went 26-4 that season and it was his only ML season without a save or save opportunity. It was decried as a gimmick, and the Cy Young instead went to Escobar. Granted, Escobar was more effective that season, but the voting was close as I recall, and Damon had the better W/L record.
A difference of 2-3 votes for Escobar in Season 9 going to Damon's 26-4 record, and suddenly Escobar has only 3 Cy Youngs and Damon has 2 Cy Youngs.
Had I successfully traded for Damon a few years earlier (and still used him in such a way to let him accumulate wins) or not let him walk in FA where he went back to part-time closer costing him wins, and Damon is easily (by his effectiveness) a 200-90 W/L pitcher, at least.
This whole thing is evidence of a very simple (to me) point - these two pitchers were basically the same player in World Major Leagues when they were on the mound.
That one was a SP and the other was used/misused as a MR/sometimes closer is a silly reason to draw distinctions between them for purposes of HOF voting, just like it was for purposes of Cy Young voting.
I'm not sure if I am voting for either of them yet, but I am pretty sure I won't be picking just one and leaving the other out.
For me, they may as well be joined at the hip in HOF voting - just as they are in statistical effectiveness.