SBN Blog Beyond the Boxscore has a great post up as of today in regards to Catcher's Block Percentages in 2009. You can find the post HERE. I believe this article is particularly interesting for Angel fans due to our constant defense (Mathis) vs. offense (Napoli) argument.
The formula to determine how strong a catcher is in regards to blocking balls in the dirt was constructed by SBN poster Dan Turkenkopf formula and apparently is still being tweaked a bit. The basics of it after the jump...
Each wild pitch or passed ball saved is worth .27 runs (based on run expectancy and the timing of the events). Full methodology is described here.
There is more to the formula that I don't fully understand (Im not a statistics whiz). However, it seems that he does take into consideration what exactly defines a "ball in the dirt" and from what I understand, the second chart includes the average distance a catcher sits from the plate. (How the hell do these guys do this sh*t?)
Looking at the first chart Jeff Mathis comes out the better catcher defensively as many of you may expect. His block percentage in both charts is 91% of balls in the dirt. According to this formula, Mathis actually SAVES us 2.8 runs a
game season if I understand it correctly. In comparison to Mike Napoli who has a block percentage of 88% and actually COSTS us 0.8 run(s) a game.
It should be noted that Mathis caught almost 100 less innings than Napoli last year which of course gives Napoli a greater degree of error (right? Correct me if Im wrong). It should also be noted that Napoli has pretty much remained the same defensively when using this formula in both 2007 where he was an 88% of pitches blocked and 2008 where he dipped to 83%. Finally, last year, Jeff Mathis was actually at the top of this list with 94% of balls in the dirt blocked.
I would love some input from the HH statheads on this. Im still not even entirely sure what all of this means but thought it was of interest.