I was just thinking about this too. I'd be curious as to what his numbers would be like with Johan back in the day, or when the Twins actually had an MLB caliber pitcher or two on the roster, let alone one with a high enough "respect" factor to earn a call on the corner. I'm not just blindly trying to defend Mauer, but I find it hard to believe he'd be among the very worst in the league at what is supposedly a basic part of the fundamentals of catching. He's been catching his whole life, he's very athletic, he has star-status and respect among the league. I could see him being average, or even a little below average, but being near dead last among all catchers? I'm thinking there's a lot more to this stat than just a catcher's ability.