/cdn.vox-cdn.com/uploads/chorus_image/image/7552037/153673128.0.jpg)
If you were—for whatever reason—looking for one way in which the St. Louis Cardinals' Yadier Molina has something to learn from his older brothers, you could do worse than to read up on pitch-framing, which is probably the most important and annoying sabermetric discovery since DIPS or the replacement level. (Here's one of the early articles on the topic, from former Baseball Prospectus writer and current Houston Astros employee Mike Fast.)
Basically: Catchers have an astonishing amount of influence over the strike zone umpires call if this research is accurate—so astonishing that Jose Molina might actually be one of the best catchers in baseball. Clubhouse Confidential, MLB Network's numbers-loving paean to internet fans, did a nice interview with a current BP writer, Ben Lindbergh, summarizing the research, which you can watch here. (For whatever reason, MLB.com doesn't allow embedding of this particular video.)
There's also a great look at what a catcher can do to influence this—to fool the umpire, basically. Yadier has done well-enough by this measure, but Jose Molina has gone from a completely unremarkable backup catcher to an arcane catcher-sorceror. 50 runs is the difference between an all-star and a replacement player.
Unlike most sabermetric finds, my hope is that this one can be made irrelevant as soon as possible. Fooling umpires is an interesting skill to have, but the take-away isn't just that Jose Molina is valuable—it's that there should probably be some consequences for umpires who don't know what the strike zone looks like.