It doesn't take a lot of effort to understand why "advanced stats" have a larger following in baseball than they do in football, basketball, hockey, soccer, or any of the many, many sports in which stats beyond standard box score fare exist. The reason is because, more than in any other team sport, baseball is a long series of individual events. It's easier to analyze the offensive impact of Matt Carpenter during a given plate appearance than it is the offensive impact of Todd Gurley during a given play or Vladimir Tarasenko during a given shift because Carpenter isn't dependent on an offensive line or on passes—it is Matt Carpenter alone in the batter's box against a pitcher (and a defense behind him, but that's where increasingly sophisticated batted-ball statistics come into play).
Speaking strictly on the basis of these individual matchup statistics, St. Louis Cardinals catcher Yadier Molina was an MVP candidate in 2012 and 2013. Among National League position players, Molina ranked 8th and 7th in fWAR; 5th and 7th in bWAR. And the calculus isn't exactly difficult to grasp: he posted wRC+ of 138 and 133 in 2012 and 2013 and was, anecdotally and through conventional fielding metrics such as fielding percentage and caught stealing rate (not to mention the general unwillingness of opponents to be too daring on the basepaths with Yadi behind the plate), a superb defender.
But while Yadier Molina's defense remained strong in 2014 and 2015, his offense clearly took two major steps back. In 2014, he was somewhere in the neighborhood of a league-average offensive player—a 102 wRC+ with his lowest ISO since 2010, the year before he started to garner nearly as much acclaim for his bat as for his glove. He didn't receive any MVP votes, even down-ballot ones, though he probably could've mustered one or two had he played more than 110 games (Dee Gordon got one with a lower wRC+ and below-average defense—though his 64 steals were, um, more than Yadi put up). Molina's 2015, however, marked a precipitous offensive downturn. In 530 plate appearances, he had four home runs, his lowest on-base percentage since a 2006 season in which his offense was so wretched that he was below replacement level even with Gold Glove caliber defense, and an offensive reputation which fell so quickly that even though he started 30 games in 2015 batting seventh, there remained a chorus (which often included myself) begging for him to bat eighth. It's not that we questioned whether he should be starting or anything quite that bold yet, though it is a bit tougher to grasp a potential eight-hitter as a player of MVP-level importance.
But when Yadier Molina was injured at Wrigley Field on September 20, amidst this mediocre-at-best offensive season, the reaction of baseball media was universally that this was an injury verging on catastrophic for the Cardinals. This wasn't just local media, either—Molly Knight, whose principal professional baseball association is with the Los Angeles Dodgers, tweeted after the injury that "no player (is) more valuable to any team than he is." This was met with criticism (which went full-circle into criticism of Cardinals fans because this is the state of Baseball Twitter in 2015), but the overall sentiment is clearly that Yadier Molina is more valuable than his statistics.
What Molina is purportedly excellent at, beyond what we can measure, is handling the Cardinals pitching staff. Even with staff ace Adam Wainwright missing the majority of 2015, the Cardinals had the lowest team ERA of my lifetime. But how much of this is Yadier Molina and how much of this is the Cardinals staff? It's tough to tell, really, especially since the vast majority of Cardinals innings this year were pitched by men who have never known a regular starting catcher in the Majors other than Yadier Molina. But the major exception to this rule, salty veteran John Lackey, had his best season since 2007 by both Baseball Reference and Fangraphs WAR. Not that I read too much into Catcher ERA, for a variety of reasons, but Yadier Molina's 2015 CERA was 2.80 while teammate Tony Cruz's was 3.51. But again, I don't know how much of this is actually attributable to Yadier Molina. Some, probably. But all of it? Probably not. But maybe?
The unknown is a little bit scary, but even over the last few years, perception of the importance of a great defensive catcher has changed dramatically. My favorite quote which embodies this ethos comes from a New York Yankees report, which, as observed by Grantland's (RIP) Ben Lindbergh, reads: "Jorge Posada could hit like Albert Pujols and Jose Molina could hit like Jose Molina, and Molina would still be better." I'm not sure if I'm quite willing to co-sign that, but I'm at the mercy of people smarter than I am who would also not be willing to co-sign that. Because this wasn't some half-baked fan theory—these are smart insiders. And they prefer Jose Molina, 2.8 career fWAR in 2,795 career plate appearances, to a trumped-up version of borderline Hall of Famer Jorge Posada. It's entirely possible that the Yankees, and every MLB team for that matter, have proprietary systems which suggest things along these lines. As much as fans like to make fun of front offices perceived to be anti-sabermetric, even the most ardently old-school organizations are lightyears ahead of where the Moneyball Oakland A's were in 2002 and where websites frequented by interested yet outsider baseball fans are in 2015.
In its simplest terms, we have no freaking clue how valuable Yadier Molina is. Maybe he's exactly what player value measures on the internet say he is. Maybe he is the most valuable player in baseball history. Likely, he's somewhere in-between, but there's an awfully sizable gap here. But I've also learned to embrace the mystery. I don't need to know how important Yadier Molina is—I'm not going to spend my time arguing with San Francisco Giants fans that he's better than Buster Posey (after all, it's not like the three time World Series champion Posey doesn't appear to be really, really good in his own right as a leader of pitching staffs, which have had three different aces during his title runs), but if some Cardinals fans want to do this, go for it. Giants fans will have the edge in hard numbers, but that we don't know what to do about the pretty significant intangibles means we can argue about silly things like which not-even-close-to-available-on-the-open-market catcher we prefer. And even if they were available, it's not like we as fans are going to be the ones making the decisions. Perhaps John Mozeliak and Brian Sabean have a very good idea of what exactly their superstars catchers are worth. Until they let us in on the secret, I'm just going to sit back and enjoy not knowing it all. It's fun to know that no matter how much we read about baseball statistics, not all frontiers have been explored, that what we have is a blueprint and not a solution. That perhaps, decades from now, contrary to our contemporary standards of logic and reason and objectivity, Yadier Molina is as valuable as we all believed he was at our most boisterous.