"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 e-mail 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

Most of the e-mail I received raised one or both the the two issues M.H. raised. Put more generally:

  • Shouldn’t a catcher arm rating reward a strong-armed 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
full-time catcher can handle a significant number of innings from ten or more different pitchers in a season, we might expect the
runner-holding 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 caught-stealing 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 year-to-year 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.
1998-1999      +0.59
1999-2000      +0.57
2000-2001      +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 caught-stealing 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 year-to-year 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 caught-stealing 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 full-time 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
    Blanco         28 38   58%   2  15.1
    Other Brewers  58 16   22%   1  -1.1
    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 base-stealers:

               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 caught-stealing 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

  • Mike Piazza and Ivan Rodriguez. Yet another thing we’d expect if pitchers played a significant role in determining
    catcher caught-stealing numbers: catchers generally wouldn’t put together long stretches of years with extreme (good or bad) CS

    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
    ‘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 would-be opposing
    base-stealers 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 stolen-base 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 year-to-year 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 caught-stealing 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

Michael Wolverton is an author of Baseball Prospectus. You can contact him by
clicking here.

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