So recently I've been looking at catcher defense articles due in large extent to Dan Turkenkopf's articles at Beyond the Box Score. Most catcher defense articles have scored Gregg Zaun extremely high at his ability to block balls. It also appears that Matt Wieters picked up on that skill with most rating him very good at it although not quite elite.
Anyway I'd thought I'd share some of the information I had found on catcher defense and how Wieters stacks up (pretty darn good) Some of you have undoubtedly seen some of these articles but hopefully I have some new information to share. This is going to focus only on blocking balls so I may do a follow-up article at some point.
If you're interested in game-calling there's an article examining Posada's game-calling vs. Jose Molina's gamecalling looking at C.C. Sabathia here at the hardballtimes (boo Yankees! Well it tells us that Posada ain't the best defensive catcher. So ummm yay?)
Anyway analysis after the jump
Dan Turkenkopf of SBNation's Beyond the Box Score has done some very good work on catcher block percentage in recent years. He started in 2008 publishing historical catcher defense data for 2005-2007 and has posted 2009 results and currently has projections for 2010. He basically has tried to quantify how well catchers stop runners moving up on balls in the dirt. In 2009 he added balls in the dirt with two strikes, because in that rare event batters can run to first. He also used pitch fx data to decide if a pitch would have hit the ground if the catcher had not caught the ball.
I would basically ignore the 2005-2007 data except that it shows that we Orioles fans may have been spoiled in 2009. We had Gregg Zaun, possibly the best currently active pitch blocker.
In 2005 he placed third in total runs saved by blocking balls while ranking second in runs saved over 120 games (the normal amount starting catchers play. Unless Torre is running Russel Martin into the ground.) Zaun dropped dramatically as he caught just over half the innings from 2005 ranking just 12th out of 32 catchers and just 11th in runs per 120 games. In 2007 he returned to form as he caught 838.33 innings (close to the midpoint between the innings caught the two years prior) and placed fourth in total runs and third in runs per 120 games.
What the 2005-2007 data basically tells us is that Gregg Zaun was vyer good at pitch-blocking, probably ranking fourth or fifth in ability during those years. This is the guy we hired to mentor Wieters.
So how did Zaun and Wieters stack up in 2009? In 2009 Zaun ranked first. First! Dan used two different pitch fx methodologies to determine if a ball should hav hit the ground. According to the simple one Wieters ranked 12th out of 55 catchers. The other methodology used a formula by Harry Pavlidis to determine a catcher's placement. Using this Wieters ranked 8th.
It would appear that Wieters either was already very good defensively from college and the minors or that Zaun did an excellent job at mentoring Wieters. I suspect that it was probably a combination of both. While his offense overshadowed everything in the minors we did hear that his defense was quite good especially his throws to second base.
The 2010 projections place Zaun fifth and Wieters 20th. The projections were made using Marcels which is basically a 3/4/5 weighting of the past three years. As Wieters has only been up for the past year his placement and ability are more suspect. While Wieters did much better than expected in 2009 defensively part of that may have been due to Zaun. It is quite likely that we will see some regression towards the average without Zaun's mentorship.
Well knowing that both Zaun and Wieters were quite good at blocking pitches a question arises. Just how difficult are the pitches to block that they are blocking? Are they missing pitches with lots of movement like a nasty slider or are the pitches fairly straight and easy to catch.
Dave Allen, most notably of fangraphs, recently did some work evaluating the difficulty of blocking a ball by pitch type and location for Baseball Analysts. In his first article he discovered that fastballs had the lowest frequency of passed balls or a wild pitches while knuckleballs were the highest. I'm just going to copy and paste his table of rates below for simplicity's sake.
| Pitch Type | Rate |
| Fastball | 0.24% |
| Changeup | 0.49% |
| Curve | 0.60% |
| Slider | 0.73% |
| Knuckleball | 1.37% |
Well since Wieters won't be catching knuckleballs how exactly is this useful? Because in Dave Allen's follow-up article he posted the best catchers at blocking more difficult pitchers.
He ranked a catcher's skill by calculating their passed balls and wild pitches minus their expected number of passed balls according to pitch difficulty (this means that negative values indicate good catcher defense). Greg Zaun caught the toughest pitches during the pitch fx era (2007-09). Dave Allen also provided leaders for catchers "(who have seen at least 5000 pitches with runners on) with WP/PB-expected per 1000 pitches.
Here are the top 5 leaders for that list
Wieters performed admirably just below Zaun which indicates that Wieters could be an elite defensive catcher. Interestingly enough Posada ranked dead last for this leaderboard with a positive 4.9 more wild pitches/passed balls per 1000 balls. That was one entire ball more than Olivo at 3.9. The third-worst catcher at this was Inge at 2.7 of the Detroit Tigers when he went back to catching after being a converted third baseman for years in 2008. So basically Posada is terrible at blocking balls based on their expected difficulty.
Basically there is some information that Wieters could be very good at blocking balls similar to Zaun which is an added bonus to his offensive potential. This skill isn't worth all that much by itself providing less than a win in difference between the worst and the best catchers over one season. However this should mean that over Wieters 6 years he could provide an extra 2-3 wins in value. The question remains how much will Wieters suffer from being without Zaun as a mentor. From all the information we have there seems to be a high likelyhood that Wieters could be the complete package. He could end up being an offense-minded catcher who is still extremely good defensively. Watch out Al East we're going to have the best catcher in the game not named Mauer. And he may end up being better than Mauer
EDIT: And since I've been working on this for a few days I of course forgot to mention that all the resources I linked to are worth reading by themselves as i left a good portion out. Most of the links have information about all active catchers. I may very well do another article later on (probably much later as this took a while) using other ways to evaluate catcher defense.
If you're interested in catcher defense (especially non-blocking balls stuff) check out these additional sources
http://www.drivelinemechanics.com/2009/10/13/1082419/2009-catcher-defense-filling-in (one of the best resources although not updated)