“Yadi knows everything about every single hitter, exactly what to throw. If you execute your pitches and throw them where he wants the ball, you’re going to get hitters out, have a better ERA, win the game. I seriously believe that all the success I’ve had is totally on him.” – St. Louis Cardinals’ rookie Shelby Miller

“It’s not just instinct. It’s sense, based on how a hitter’s standing, how he responds to the pitch or two before, and he’s very creative in how he makes his adjustment based on what he sees with the hitter and knowing what his pitcher can do. That’s art.” – Former manager Tony La Russa

“With him catching me, I never had to worry. It’s never like he was back there guessing. He gets to know his pitchers. He got to know me, what I like to do, my strengths and weaknesses. When I got into trouble, what do we need to do to get me out of it? Those are the things he not only has to remember for one guy, but a whole staff. The ability to do that is pretty amazing.” – Milwaukee Brewers’ pitcher Kyle Lohse

The quotes listed above are just a small sampling of the praise that has generally rained down on Yadier Molina over the past 5 seasons or so. He’s widely regarded as the best defensive catcher in baseball thanks to his sublime framing skills, his Howitzer arm, and a glove so soft that Adam Wainwright once described it as a pillow. But can the mighty Molina really lower a pitcher’s ERA while taking runs off the board, as Shelby Miller and so many others claim? Or is there something else at work here? Let’s dive into the data to see if we can catch a glimpse at the inner workings of St. Louis’ finest:

So, at least by the simplest of measures, it appears that the hype surrounding Molina is indeed justified. If we strictly go by ERA, St. Louis’ pitchers have allowed fewer runs with Molina behind the plate in 8 of his 10 seasons and over the course of the sublime catcher’s career he’s been responsible for a half a run drop in his staff’s ERA.

The youngest Molina brother has only gotten better with age too. Since the beginning of the 2009 season, Molina and his pitchers have posted a 3.48 ERA with him behind the plate, compared to a 4.24 ERA with anybody else. There are only a handful of catchers in baseball with even one season of ERA improvement that’s more than 0.76. Molina’s been averaging that for 5 straight years while spending more innings behind the dish than any other ballplayer.

At least some part of Molina and his staff’s success has to be attributed to the way he calls a game. St. Louis’ pitchers rarely shake of their catcher and the younger members of the staff (Miller, Trevor Rosenthal, Michael Wacha, among others) follow Molina’s instruction to the letter. And while it’s difficult to tell whether or not that the majority of that drop in ERA is caused by Molina’s pitch selection, there are a couple of things the All-Star catcher does that are guaranteed to keep runs off the board.

The first (and potentially most important) cause of the Molina effect is Yadier’s ability to block any ball thrown his way. The Cardinals as a team have allowed fewer passed balls and wild pitches than every other team in baseball for the better part of the past decade and Molina, who catches between 75-80% of his team’s games annually, is the biggest reason why.

This year alone Cardinals’ catchers have allowed just 26 passed balls/wild pitches and no other team, outside of Philadelphia, is even in the same ballpark. Not only does every blocked ball prevent base runners from advancing, but it also has the added effect of instilling confidence in a pitcher while giving them a greater variety of options with two strikes. Shelby Miller and Adam Wainwright can throw vicious, bouncing curveballs into the dirt all day long with the knowledge that, no matter what, Molina will be there to keep the ball in front.

Yadi is also second to none at taking runners off the bases. His arm strength is the stuff of legend and his extensive history of picking runners off of 1st base keeps lead-offs to a minimum. His effect on the running game is also unmatched in baseball today. As we saw back in May, most runners are cautious when even thinking about swiping a bag. Molina allows the fewest stolen base attempts in the league and those brave souls that are foolish enough to run are gunned down at an elite 45% rate.

What Yadier Molina is doing on defense right now is almost otherworldly. He’s one of the 3 or 4 best catchers in the game at every single aspect of defensive play and thanks to his production at the plate. He’s a legitimate MVP candidate in the National League and at this point a 6th straight Gold Glove is a foregone conclusion.