So give this til the end of the season, check back, see how it looks. Might be nothing. But for now, it looks like something. Or it doesn't make sense.
So, my original question was:
Does WPA correlate with ERA-, with respect to a team's bullpen ala relief pitchers?
The answer to that question is yes, see below.
My other original question was: does it reflect on the manager?
Meaning, does a high WPA but average ERA- mean that the manager was able to get the most out of his guys.
My thought process was something like this, 'does a manager who's average bullpen accumulates a lot of WPA deserve credit?'
I don't know. Here's some charts:
2022 -AKA "Worst Year Ever"
2019 - Woody's First Season as the Big Dog
2016 - Peak Banny
One thing is abundantly clear: what Woody has done this season is special. And unusual. I checked 2019 to see if he was always this shitty. Pretty average that year. So is managing a bullpen a repeatable skill? That would take a lot more work.
This shows that better bullpens have strong (around 0.5 rsquare) correlation with increasing individual game's win probabilites over a season.
Pretty funny that Houston was at the top twice, and now Baltimore is. I suspect those bullpens are being managed by FO's, not former baseball players, but who knows.
Let me know what you think, ok? Am I off my rocker?