I don't comment or post often and when I do it is usually about catcher's defense and usually to express criticism of sabermetric's inability to quantify catching defense and how most sabermetricians therefore downplay its importance or relevance. The second half of that sentence has been changing in the last year or so as better and better attempts that have been made to quantify its value. I still think this study has some holes in it and perhaps still undervalues ability to frame pitches, but it is by far the best attempt at bringing pitch-framing into saber-speak that I have seen to date. It even includes some solid scouting notes complete with video samples on the subject.
For those that won't read it all (it's well-worth the time), a few of the key conclusions: pitch-framing alone can result in anywhere from +2 WAR to -2 WAR a year (with a few extreme examples well above and below that). Top five catchers in terms of pitch-framing ability over the last 5 years combined: 1) Jose Molina; 2) Russel Martin; 3) Torrealba; 4) Lucroy; 5) Yadi. The Bottom 5 (with 5 being the worst): 1) Johjima 2) Kendall 3) Posada 4) Laird 5) Doumit. Some of the order surprised me, but, on the whole, I thought the order was pretty close to my observations (not surprisingly, I feel that catchers who spent alot of time in our division tended to surprise me the least in terms of their rank in this study). The study found that, on average, Yadi saves the team 8 runs per 120 games played by framing pitches alone. The author acknowledged that his approach to normalizing for pitching staff quality would likely understate the pitch framing ability of catchers that have been on one team for the previous five years with relatively stable rotations (which I think would include Yadi). When you do just a little extra math, his results indicate that Yadi, for instance, gets 1 extra strike called every two games by framing pitches. Based on my personal experience as a catcher (i.e. anecdotal), I think that is probably a low estimate for a top five pitch-framer in the world.