Best. Season. Ever?

Yesterday, I talked a little bit about why I don’t really care who baseball writers vote as the AL MVP, because we pretty much all realize it’s Joe Mauer, and it’s not particularly close. In fact, Mauer’s having such a good season that there’s a pretty good chance it will go down as the best season any catcher has ever had in the history of the game.

Mauer is currently hitting .383/.448/.653, good for a .464 wOBA in 415 plate appearances, the best mark in baseball. His +46.5 wRAA is better than any non-Pujols player in baseball, and he missed the month of April. The next best catcher in wRAA this year – Victor Martinez at +15.9, and he’s not really a full-time catcher. Mauer is a catcher hitting like a DH, and that just doesn’t happen very often.

The current standard for best catcher season of all time is probably Mike Piazza’s 1997 campaign. He hit .362/.431/.638 for a .454 wOBA, and because he played almost every day, he racked up 633 plate appearances and a +63.9 wRAA. Mauer’s rate stats are better, but he’s not going to match the counting numbers that Piazza put up thanks to his one month stint on the disabled list.

However, that’s just the offensive side of the game. Piazza wasn’t a defensive asset, even early in his career. Runners advanced 187 bases against Piazza in 1997 (via stolen bases, wild pitches, or passed balls), while he only nailed 45 runners attempting to advance. Mauer’s only had runners take 74 bases on him this year, and while his 16 “kills” aren’t that impressive, his reputation is keeping guys from running at will.

How much does that stuff matter? Well, in 1997, Piazza was rated as a -2 defender by Sean Smith’s catcher defense formula, while Mauer has been +10 or better in each of the last two years. Mauer’s ability to keep guys from running on the bases saves his team runs, and that goes in his ledger as well, to the tune of something like 10 extra runs that Piazza didn’t provide.

Remmeber, Piazza’s lead in wRAA is +17.4, but Mauer makes up most of that with his defensive abilities. As of right now, it’s pretty close to a push between ’97 Piazza and ’09 Mauer, but if Joe keeps hitting in September, he’s going to pull away. This very well could go down as the best season any catcher has ever had.