That's one of things that has always puzzled me, or intrigued me, about catchers. How much positive impact do catchers have on the pitchers they are catching? Some catchers are obviously calling for certain pitches in games, and that can affect things, but in the grand scheme of things, how much to pitchers rely on their catcher? I suppose veterans would be less reliant than younger pitchers, but still, I wonder about these things and I don't know how you measure or use stats to accurately rate the job that a catcher does behind the plate, other than pitch framing or throwing out steal attempts.