"The Man With the Golden Gun", an article that
ran last month on this site, recognized the most valuable and least valuable catcher arms in the majors last season. That piece
generated a lot of reader response, including this email from M.H.:
I have my doubts about this Stolen Base Runs Prevented statistic. It seems to penalize catchers who are so good that the opponents
don’t run on them; you hint at that with the Ivan Rodriguez comment. Also, bases are stolen more on the pitcher than the
catcher, aren’t they? It is not clear to me that this statistic is telling you anything at all about the defensive abilities of
catchers.
Most of the email I received raised one or both the the two issues M.H. raised. Put more generally:
 Shouldn’t a catcher arm rating reward a strongarmed catcher who prevents runners from even attempting to steal?
 Aren’t catcher caught stealing numbers largely determined by things beyond the catcher’s control, especially his pitchers?
I’m going to save the first question for a later article, and focus here on the issue of the pitching staff’s influence on a
catcher’s numbers.
I’m not going to be talking about individual pitchers here. There’s no doubt that the pitcher has a huge influence on the success or
failure of a particular steal attempt, and it pretty much follows that an individual pitcher who’s especially good (or bad) at
keeping runners close can help (or hurt) the catcher’s CS numbers during the innings he pitches.
So catchers’ caught stealing numbers must be measuring pitchers to a large extent, right? Not necessarily. The thing is, while one
pitcher can make a difference when he’s pitching, a catcher doesn’t work with just one pitcher. Especially in today’s game, where a
fulltime catcher can handle a significant number of innings from ten or more different pitchers in a season, we might expect the
runnerholding ability of the different pitchers on the staff to even out over the course of the year.
How do we test this? We can start by checking whether catcher caughtstealing numbers tend to stay consistent from year to year.
That is, do the catchers with the best CS numbers one year tend to be the best the next year, and are the worst one year also the
worst the next?
To answer that, we want to look at the correlation of catcher caught stealing from year to year. The correlation coefficient
measures the strength of the relationship between two sets of numbers. Correlation coefficients range from 1 to 1. A correlation of
1 means the numbers are perfectly consistent, e.g., a high number one year means a high number the next year. A coefficient of 0
means there is no relationship between them at all.
Here are the yeartoyear correlations of catcher caught stealing percentage for each consecutive pair of years for which I have
data (minimum 50 stolen base attempts against each season):
Years Corr. Coeff. 19981999 +0.59 19992000 +0.57 20002001 +0.78
(I used CS% rather than Stolen Base Runs Prevented because CS%, as a rate stat, isn’t measuring playing time. The correlations for
SBRP are about the same for the years I checked.)
Those are pretty high numbers. For comparison, the correlation coefficient for pitchers’ ERA from 2000 to 2001 was +0.40, and for
hitters’ batting average those same years it was +0.48. The bottom line is that knowing a catcher’s CS% from one year tells you a
lot about what it’s going to be the next year.
That’s some evidence that catcher caughtstealing numbers are measuring the catcher, but it isn’t conclusive. After all, most
catchers stay with the same team from one year to the next, and therefore you’d expect them to catch largely the same pitchers from
year to year. Maybe the high correlations are just reflecting the high yeartoyear overlap in the pitchers a catcher handles.
Maybe, except that there are an awful lot of examples, just from recent seasons, that seem to indicate that the catcher, not the
pitching staff, plays the predominant role in generating the catcher’s CS numbers. Here are just a few:

Henry Blanco. If pitchers were playing a significant role in determining catcher CS numbers, we’d expect that teammate
catchers would have roughly the same caughtstealing numbers, given enough opportunities. In particular, we’d expect the guys who
are throwing out the most runners in the league to have teammates who also throw out a high percentage of their runners.In most cases we can’t test this, because most of the league’s top throwers are fulltime catchers, and their backups don’t see
enough stolen base opportunities to get a meaningful caught stealing percentage. But Blanco, who has caught around half the time
during each of the past three seasons, gives other catchers enough chances to compare:
1999 SB CS CS% CPO SBRP Blanco 59 37 39% 0 8.6 Other Rockies 104 20 16% 2 6.2 2000 Blanco 28 38 58% 2 15.1 Other Brewers 58 16 22% 1 1.1 2001 Blanco 43 27 39% 1 6.7 Other Brewers 52 17 25% 0 0.2
If the pitching staff was playing an overwhelming role in determining catcher CS numbers, we wouldn’t expect to see a catcher
dominate his teammates this consistently and thoroughly.  Ed Taubensee. Here’s something else we’d expect if pitchers were playing a significant role in determining catcher CS
numbers: When a catcher changes teams, the new team’s past CS numbers should be better predictors of what the catcher will do with
them than his own past CS numbers. In particular, if a catcher had extreme caught stealing numbers (good or bad) with one team, it’d
be surprising to see those extreme numbers continue for a new team–and an entirely new set of pitchers.Taubensee is one of many examples that refutes that corollary of the "it’s mostly the pitchers" theory. From 1998 to 2000
with the Reds, Taubensee had some of the worst throwing numbers in the majors:
Year SB CS CS% CPO SBRP Taubensee CIN 1998 78 18 19% 0 3.9 Taubensee CIN 1999 97 15 13% 0 8.5 Taubensee CIN 2000 50 12 19% 0 2.3
At the same time, the Cleveland Indians as a team were catching an average number of basestealers:
SB CS CS% CPO SBRP CLE 1998 110 42 28% 0 2.6 CLE 1999 119 44 27% 3 3.6 CLE 2000 110 38 26% 0 0.7
So when Taubensee joined these average Indians pitchers last year, did he become average himself? Hardly. Instead, he put up the
worst caughtstealing percentage of any catcher in the past four years (minimum 10 attempts), while the rest of the Cleveland
catchers (mostly Einar Diaz) were well above average.
SB CS CS% CPO SBRP Taubensee 29 1 3% 0 4.3 Other Indians 99 47 32% 2 7.9
Just as telling, Jason LaRue took over many of Taubensee’s innings with the Reds’ pitchers, and put up some of the best catcher throwing numbers of recent
years. 
Mike Piazza and Ivan Rodriguez. Yet another thing we’d expect if pitchers played a significant role in determining
catcher caughtstealing numbers: catchers generally wouldn’t put together long stretches of years with extreme (good or bad) CS
percentages.In the first few years of Mike Piazza’s career, it was common to hear the Dodger pitchers being blamed for Piazza’s troubles with
opposing baserunners: "It’s Tom Candiotti‘s fault," "It’s Hideo Nomo‘s fault," "It’s Ramon
Martinez‘s fault." Those claims grew less and less credible as the years went on, Piazza changed teams, and the list of
Piazza’s batterymates grew. ("It’s Al Leiter‘s fault," "It’s Mike Hampton‘s fault," "It’s
Kevin Appier‘s fault," "It’s…" I don’t think so.)
Year SB CS CS% CPO SBRP Piazza LAD 1996 155 26 14% 1 12.1 Piazza LAD 1997 112 34 23% 0 1.6 Piazza L/F/N 1998 114 35 23% 0 1.5 Piazza NYM 1999 115 31 21% 0 3.6 Piazza NYM 2000 110 15 12% 0 10.7 Piazza NYM 2001 113 22 16% 0 7.7
Since 1996 (the earliest year for which I have his numbers), Piazza’s CS% has been safely below average in every season. The
fluctuations you do see in his numbers seem to have little to do with pitchers. The 1997 Dodgers staff was largely the same as the
1996 version, and there was a fair amount of overlap between the 1999 and 2000 Mets staffs as well.You see the same sort of consistency on the other end of the throwing spectrum in Ivan Rodriguez. The only overlap between the 1996
and the 2001 Rangers staffs was Darren Oliver, and he disappeared a couple of years in the interim. But despite the high
turnover rate for Ranger pitchers over the past six years, Rodriguez has caught right around half of the wouldbe opposing
basestealers every year like clockwork.
Year SB CS CS% CPO SBRP Rodriguez TEX 1996 46 44 49% 10 19.1 Rodriguez TEX 1997 37 40 52% 9 18.1 Rodriguez TEX 1998 38 42 53% 7 17.9 Rodriguez TEX 1999 34 38 53% 10 18.1 Rodriguez TEX 2000 20 14 41% 1 4.1 Rodriguez TEX 2001 23 23 50% 3 9.0
Those are just a few examples, but I’ve run across many others that are inconsistent with the "it’s mostly the pitchers"
theory. Of course, you could also probably come up with a few examples that would seem to support the theory. In fact, here’s
one–Mike Matheny‘s throwing numbers took a big step forward when he joined the Cardinals two years ago:
Year SB CS CS% CPO SBRP Matheny MIL 1996 52 19 27% 2 1.8 Matheny MIL 1997 69 34 33% 5 7.9 Matheny MIL 1998 67 19 22% 0 1.6 Matheny TOR 1999 40 16 29% 0 1.3 Matheny STL 2000 44 46 51% 3 16.9 Matheny STL 2001 31 25 45% 5 9.7
These individual anecdotes are useful for helping us understand the issue–not to mention getting some actual baseball players into
the discussion–but to really get at the question of the pitching staff’s role in catcher CS numbers we need to return to looking at
catchers as a group. We want to check correlations as before, but this time, to remove the potential doubts about the correlations
shown above, we want to look at catchers who we know aren’t catching the same pitchers from one season to the next.
To do that, I looked at catchers that changed teams. I took all catchers who had at least 50 stolenbase attempts against them with
two different teams during the past four seasons, and measured the correlation of their total CS% with the first team to their total
CS% with the second team. (For those catchers who qualified with three teams, I grouped the first two teams into the
"before" group and had their last team be the "after" group. I did it this way to make sure that the big Matheny
jump mentioned above was included in the comparison.)
The correlation coefficient for CS% from one team to the next was +0.53. That’s still quite strong, and not a whole lot lower than
the yeartoyear correlations for all catchers shown above. In other words, knowing a catcher’s CS numbers with one set of pitchers
tells you a lot about what they’re going to be with another set of pitchers.
The bottom line is that all the evidence that I’ve seen on this issue indicates that catcher caughtstealing numbers are measuring
the catcher, without too much interference from the pitching staff. That doesn’t mean it’s impossible that there will occasionally
be extreme pitching staffs that can have some positive or negative impact on a catcher’s numbers, but it does mean that the next
time a fan tries to defend his favorite catcher by blaming all his troubles with baserunners on his pitchers, you’d be wise to be
skeptical.
Michael Wolverton is an author of Baseball Prospectus. You can contact him by
clicking here.