Friday, January 07, 2011
Catcher Defense 2010Posted by JT Jordan
Estimating a player’s defensive value is quite difficult.
I know, I know—duh. BUT, I would venture to say that it’s a tad bit easier to estimate a catcher’s defensive value compared to other positions. At least, most of it. There are, of course, certain aspects of a catcher’s impact behind the plate that we can only feebly grasp at—game calling, for example, and framing pitches, amongst other things. But we can still make a reasonable estimate of things that we do know about—the catcher’s caught stealing rate, prevention of wild pitches or passed balls, things like that—and while it is certainly influenced by the pitching staff the catcher works with, there is one piece of information we have for catchers that separates them from the rest of the position players: opportunities. We know the number of plays made by infielders and outfielders, yes, but not the actual amount of chances they had afield. When it comes to catchers, we do know how often a baserunner attempted to swipe a bag; we do know how often a catcher allowed a passed ball with a runner on and a base open for the taking, and so on.* So in some ways, we’re a bit ahead of the curve with catchers than we are with the other positions.
When I first began studying sabermetrics, I was heavily influenced by Justin Inaz’s series of player valuation at his site, Basement-Dwellers.com (it appears to be abandoned, which makes me really sad—it was one of my favorites). In it, Justin presented a method for estimating a catcher’s defensive efficiency based on statistics that were carried here at The Hardball Times: the catcher’s runs saved or cost compared to the league average based on stolen bases allowed, wild pitches and passed balls, and the catcher’s rate of errors (differentiating between throwing and fielding errors). Matt Klaassen of FanGraphs and Beyond the Box Score has brought it back, and I thought I’d revisit his work (the more people that see this, the better) with some slight differences:
• The run values are tailored for the 2010 run environment and were derived from a Base Runs equation, which was derived from empirical linear weights. This is really just for theoretical accuracy more than anything else.
• Catcher pickoffs have been added. So we’re getting a look at not only runners removed from stolen base attempts, but also the guys being caught off guard.
• I use different denominators for the rates—rather than WP or PB per PA, I’m doing it as a function per stolen base opportunity, and errors per defensive chances, not PA or innings.
• There is an estimate for a catcher’s efficiency at handling balls in play.
Naturally, these estimates are nothing more than just that—estimates. They are approximations of a catcher’s defensive value based on freely available data located at Baseball-Reference.com or Sports Illustrated. They are by no means definitive; plenty of adjustments could be made to enhance the quality of the estimate. Think of it as a crude starting point. Commentary on the components are below, and, of course, a spreadsheet containing all of the data can be found at the very bottom.
CS Runs are the catcher’s runs above/below the league average based on their caught stealing rate. I’m only giving catchers credit for times in which they recorded an assist (in other words, I’m excluding times runners were picked off by the pitcher). The league average in 2010 was 22.9%, and the run value of the caught stealing is 0.641 (the run value of the SB in 2010 was .193; CS -.448). The best was, unsurprisingly, Yadier Molina at +9 runs saved (with an astonishing 44.4% CS rate), followed by Miguel Olivo (+7) and Lou Marson (+5). The worst was Ryan Doumit (-9), followed by East Coast powerhouse catchers Victor Martinez (-6) and Jorge Posada (-6). The spread between the best and worst is 17 runs; nearly two wins.
PO Runs are the catcher’s pickoff runs based on their rate of picking off runners per stolen base opportunity. These are relatively rare occurrences—it happened only 60 times in 68,338 opportunities (.08%)—but some players excelled at removing potential stolen base threats. Humberto Quintero led the Majors at +4 runs, with Russell Martin (+3) and Jeff Mathis (+2) directly behind him, and Jason Kendall, Kurt Suzuki and Joe Mauer at the bottom of the list with -1 run. The run value of the pickoff is about .535 runs, and the overall spread was five runs; about half a win.
Glove Runs consist of the catcher’s passed balls and wild pitches allowed per stolen base opportunity. I treat the two separately, although more often than not the two are indistinguishable and the difference between them is purely arbitrary. The run value of the passed ball is .279 runs; the wild pitch .282, so they’re essentially the same in terms of runs. I’m also including the catcher’s runs saved or cost due to catcher’s interference (.365 runs), which makes a very small difference (+ 1 run). The Major League leader was Phillies catcher Carlos Ruiz at +7, followed by Nats backstop Ivan Rodriguez (+6) and Matt Wieters (+5). At the bottom of the list are Jeff Mathis (-6), Adam Moore (-5) and Miguel Olivo (-5). The difference between the best and worst catcher is approximately a win and a half, a bit more than I imagined.
The player’s Error Runs are composed of the player’s rate of throwing errors and fielding errors per defensive chance. Following Justin’s methodology, the run value of a throwing error is about .492 runs and a fielding error .758. The best in the Bigs was Chris Snyder at +2, followed by Joe Mauer (+1) and Yadier Molina (+1), while the worst were Francisco Cervelli (-3), Jason Kendall (-3), and Brian McCann (-3). All in all, we’re looking at about a half win of difference.
Last but not least, the catcher’s Range Runs. This is a trivial addition but I thought it would be fun to throw in to the mix. Catchers don’t see that many ball in play chances—we’re talking about 30 or so chances at the most—but some catchers are a bit more adept at converting attempted bunts or weak hits into outs than others. The run value of an out made above average is .666 (infield singles are about .40 runs; the out value in 2010 is -.266). The best catcher at handling balls in play was Ryan Doumit at +1 run, followed by Ivan Rodriguez and Ramon Hernandez. The worst were Gregg Zaun, Francisco Cervelli and Russell Martin, all at -1.
Putting it all together, we get:
Name Runs Yadier Molina 16 Ivan Rodriguez 11 Carlos Ruiz 10 Matt Wieters 9 Humberto Quintero 9 Lou Marson 6 Henry Blanco 5 Yorvit Torrealba 5 Ramon Hernandez 5 Brian McCann 4
Dang, Yadier. Looks like Pudge still has it, and it's nice to see a kid with so much offensive potential in Wieters score so well in his defensive ratings.
Name Runs Chris Iannetta -4 John Hester -5 Kevin Cash -5 Victor Martinez -6 Mike Napoli -6 Adam Moore -8 Jeff Mathis -8 Ryan Doumit -9 Jorge Posada -10 Francisco Cervelli -10
Mathis is considered to be the "defensive specialist" if I remember right, so it's a bit odd to see him do so poorly. The Yankees were horrendous behind the dish last season, so switching to Russell Martin (+2) as the primary backstop could give them an extra win based on just the simple categories used. For a relatively small signing, it could have a modest impact for the Yanks.
All in all, there’s a 2.8 win difference between the best and worst catcher, which is pretty large. Of course, that’s not accounting for the intangibles, so it’s pretty apparent that the quality of defense behind the plate—even when you’re not paying attention to framing, pitch sequencing, etc.—is pretty important.
Yeah, yeah, I know...I promised you all a spreadsheet. So here it is- I hope you enjoy.
UPDATE (1/9): I've put WP and PB together (averaging the run value as well). The spreadsheet has been updated.
*As I already mentioned, naturally, pitchers can and do affect a catcher’s CS and WP/PB rates. Of course, if one is interested in estimating the catcher’s true talent, you’ll have to regress each component to the mean. I imagine this would help sift out the impact of the pitcher by at least a little bit.
JT Jordan is an avid Giants fan and runs a blog at Triples Alley. He can be reached at firstname.lastname@example.org.