From Lookout Landing....
We would expect better game-callers to post lower (CERAs), and we would expect worse game-callers to post higher CERAs. Adjusted for pitchers and opponents, of course. Obviously, if you're calling a better game, that means your pitchers are allowing fewer runs. And here's where it gets interesting. Catchers catch a lot of innings. There's nobody out there who's, say, a full CERA point better than average, but do you think a study could really pick up on a difference of 0.2? What about 0.1? With all the variables and all the adjustments, do you think that, if there were a spread from -0.1 to +0.1, any study would be able to catch it?
Over 900 innings - the average of the top 30 catchers in innings caught - a 0.1 CERA effect would be equal to ten runs. So if such a true-talent spread from -0.1 to +0.1 did exist, that would come out to a spread of 20 runs over a full season, or roughly two wins.
The implication being that, even given a spread that small, we could be talking about the best game-caller being two wins better than the worst game-caller over a full season by true talent, on game-calling alone.
This makes sense to my English major brain. Calling a good game might be a big deal, and it's not necessarily something that we can quantify just yet. Of course, that sets up this question: Does a catcher magically become a good game caller through experience, or can a lunkheaded ten-year veteran still be a lunkhead when it comes to baseball strategy? Because I've seen veteran catchers make unbelievably silly pitch calls -- a first pitch fastball to Vinny Castilla? Sure! Why not? -- so independent of any evidence, I'm not ready to assign pitch-calling bonus points to one catcher and demerits to another catcher just based on experience. That would be like assuming Bengie Molina would have better plate discipline than Buster Posey because of the disparity in major league at-bats.
But now I get how pitch-calling can make a huge difference. Until there's a way to quantify it, the choices are a) to use anecdotal evidence and personal observation when determining who calls a good game, or b) ignore it entirely because we can't properly quantify it yet. Both are pretty repugnant choices.
And I'd still like Posey to start, dang it...