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Revisiting the Link Between Pitching and Catcher Defense

Last year, I discussed sabermetric research on the question of catcher "intangibles."  Analysis of pitch f/x data showed that the catcher's skill in receiving the ball and framing the pitch could measurably reduce the pitcher's ERA.  In that article I defined the concept of pitch framing broadly: "the skill could include knowledge of individual umpire strike zones, the ability to quickly determine the available strikes in an umpire's zone as the game progresses, ability to determine which type of pitches are most likely to be called strikes, as well as the normal definition of framing, in terms of giving the appearance that a close pitch is in the strike zone."  The dubious part of those studies was the sheer magnitude of the impact of pitcher framing (up to 10 wins difference between the best and worst catcher). 

We will look at some of the analytic work in this area, and then discuss the Astros' catching situation.

Mike Fast, writing for Baseball Prospectus, has authored a fine piece on balls and strikes differentials. His article seems to confirm the catcher pitch framing role, but provides a more realistic value for the impact.  The distinction he makes is that both the pitcher and catcher are responsible for achieving "extra strikes," and he separates the pitcher effect from the catcher impact.  As a result, he concludes: " the best and worst catchers are around +/- 20 runs per season."  This means that a little over 4 wins can be gained by upgrading from the worst receiving catcher to the best.  I can recall when the new school data-driven fans were amused when baseball managers justified their use of weak hitting catchers based on the catcher's ability to work with pitchers.  Sabermetrics, relying upon cutting edge Pitch F/X data, now demonstrates that the old school view of catcher intangibles is based on a realistic foundation.

By picking out this specific issue, I haven't done justice to Fast's article.  He has attempted to integrate disparate results from pitch f/x studies of balls/strikes calls into a broader theory that explains why some pitchers are consistently better or worse than others at getting called strikes on balls outside the strike zone or non-strike calls on pitches inside the strike zone.  There is no reason to believe that umpires are intentionally biased for or against particular pitchers.  Instead, he persuasively argues that the location of the catcher's target plays a significant role in the umpire's strike calling. 

This involves skills on the part of both the catcher and pitcher.  The location of the pitch can affect the number of "extra strikes" a pitcher gets from the umpire.  For example, Livan Hernandez is one of the best at garnering a consistently larger than average strike zone, and he also is good at consistently throwing the ball to the outside corner.  The pitcher can get more calls slightly outside the zone by hitting the catcher's target on the outside.  The catcher can enhance that effect by making pitches just outside the strike zone appear to be a strike.  Who will get the worst results from the umpire? Think about a pitcher, whose command is so poor that he frequently misses the catcher's target, throwing to a catcher who makes the close pitches seem like mistakes.

This suggests to me that catcher defense can influence a team's win/loss record in ways that are significant and robust, but largely invisible to the average fan.  Besides the strong pitch framing impact, the game outcome is affected by the catcher's ability or inability to block pitches  (while also providing the pitcher with the confidence to throw sharp breaking pitches in critical situations), as well as the more obvious abilities to throw out base runners.  

Maybe this means we should cut some slack for Jason Castro's weak offensive performance last year.  Humberto Quintero's offense will never be a plus, but he has established himself as one of the better defensive catchers in baseball.  Astros fans get upset about the lack of offense out of the catcher position, but perhaps they are undervaluing the defense that the team gets from the catcher.

Richard Justice yesterday published this quote from Ed Wade about Jason Castro:

'When you stop and think about everything that was put on his plate last year. Not only does he have to figure out his at-bats, he has to figure out how we're going to pitch to the other club. He has to figure out the strength and weaknesses of the staff he's catching. You put all that stuff on a guy's plate at the same time, and his own personal statistics become somewhat secondary...he recognized first and foremost his responsibility was to help put together and execute a game plan for his 12 pitchers and understanding the opposition.

Wade goes on to describe Castro's eagerness in beating pitching coach Brad Arnsberg to the video room to start work on breaking down batters.  I'm not sure what we can expect from Castro offensively; he has shown the ability to draw walks, and I am hopeful that he can show more power this season.  But, given the significant value of skills like pitch framing, Castro's development as a receiver and  co-pilot for the pitchers may be the most important thing to watch.  Based on what I saw last season, Castro needs to improve his pitch blocking skill.  But, assuming he does that, I think the Astros have the potential to have one of the best defensive catcher tandems in the league.