It’s extremely difficult to measure a catcher’s defensive value, as you’ll notice whenever you try to look it up over at fangraphs. Every other position player has a defensive value computed into runs by virtue of their UZR but catchers don’t really have a UZR. They do have to field some balls and make throws to 1st, 2nd or 3rd on bunts and other dribblers but much of their defensive value is unique to the position. It’s difficult to measure their ability to block the plate or call a game but slightly easier to measure their value in preventing runs from scoring through caught stealings (and runners who never attempt) and by blocking balls and thereby preventing wild pitches and passed balls. Today I’m going to attempt to compare the NL catchers in terms of their runs allowed last season through stolen bases, wild pitches, and passed balls.
Here’s what we know: based on research done by James Click of BP and presented in the book, Baseball Between the Numbers, a stolen base is worth .1593 runs and a caught stealing costs a team .3687 runs. Similarly, Dan Turkenkopf (of BtB fame) figured out that, in 2007, a wild pitch or passed ball was worth about .27 runs. So let’s use that data to determine which NL catchers saved, or cost their teams, the most runs in 2008.
I used 2008’s data for SB and CS and figured out the number of base running runs against for the catcher on each team who played the most games. Then, I used THT’s numbers for (WP+PB)/G to determine each catcher’s WP and PB against. Multiplying that number times 0.27 allowed me to determine the catcher’s miss runs against. Add the BR runs to Miss runs to get total runs against. Then I used that number to compute the number of runs against if each catcher caught 150 games to give us a standard comparison. I used that number (runs/150) to compute the average for each of the starting catchers (or ones who played in the most games for each team). I was then able to determine the number of runs each catcher was above or below average (on a 150 game scale) for 2008.
It can be fairly argued that my number for the "average" catcher is incomplete b/c I simply took the average of each team’s best catcher. If I had used all the NL catchers or, perhaps more effectively, all the catchers in the major leagues, the "average" runs against would’ve been a lot higher (since it would have incorporated all the catchers who weren’t good enough to play so many games) and, therefore, it undervalues each catcher’s defense. Perhaps that’s an exercise for another day. While this may undervalue each catcher’s (or at least the best catchers’) runs against, it will allow us to effectively compare each NL starting catcher (they'll still be ordered correctly) based on their performance blocking balls and preventing runners from stealing bases. To the results:
|G||SB||CS||WP+PB||BR runs||Miss runs||Total runs||R/150||RAA|
So using my (admittedly imperfect) methodology, the difference between the best defensive catcher in the NL in ’08 and the worst was about 17 runs – a little more than a win and a half. It’s a noticeable difference but not a huge one. Once again, the oft-maligned Jason Kendall comes up on top of the defensive rankings. He was tested often behind the plate and nearly 40% of the time he rose to the occasion. He’s always had a poor defensive reputation but managed last year to throw out a higher percentage of runners than any other NL regular – nearly 10% more runners than Yadi. I suppose it’s pretty good that Yadi, in a down year, was still the 3rd best defensive catcher in the NL, his Gold Glove notwithstanding.
Yadi made some comments earlier in the offseason indicating that he recognized that last year was a poor one relatively for him behind the plate and that he wanted to improve his defense in ’09. Hopefully that’ll be the case. While choosing to run against him was a net loss for the Cards’ opposition, he did allow .350 WP+PB per game. When he broke into the big leagues, he was just as highly regarded for his ability to block pitches as he was for his arm. Indeed, last year’s (WP+PB/G) was higher than any season since his rookie season and his CS% was the lowest of his career. He’s still a very valuable defensive catcher – worth about 3 runs above the average NL starting catcher over the 119 games he played last season.
The other question, of course, is can we get more than 119 games from Yadi behind the plate in ’09. His career high games played behind the plate is 127 so I wouldn’t expect that many more despite the fact that he’s suffered injuries each of the last 2 seasons. He’s a catcher. They get banged up. Still, we’re worse off w/ every game played by Jason LaRue than w/ Yadi in the lineup. All that said, it’s reasonable to think that if we can get 8-10 more games from Yadi and he can improve his defensive performance to where it was in previous seasons (in 06 his RAA – assuming 08’s average – was 10.97 and in 07 it was 12.03), it’s probably worth another half win or so to the team’s record and, if we’re going to make the playoffs, we’re going to need every half win we can get.