Real Time Analytics

Does Catching Help Plate Discipline?

Scott Kane-USA TODAY Sports

Catchers spend hundreds of hours crouched behind the strike zone, but does that experience help them see the ball better when hitting?

With almost a full month of games and Eric Thames home runs in the books, it may seem like forever ago that Rob Manfred was terrorizing fans with his “speeding up the game” and “increase offense” agendas. One of his proposed changes for 2017 was to lob two inches off the bottom of the strike zone.

While not nearly as controversial as banning the shift or putting a runner on second in extra innings, the change represents baseball’s continued fixation with an invisible, 3.5 square foot, floating box. Whether it’s Game 7 of the World Series drawing the attention of millions or a plodding pickup game under a high-noon sun, baseball’s strike zone can never go a full 27 outs without being blamed or criticized. And no one, of course, knows the strike zone better than catchers.

In 2016, seven catchers caught more than 1,000 innings, and as recently as 2011, 14 catchers reached quadruple digits — which tied a major league record. Since umpires only work a quarter of their games behind the plate, whenever a veteran catcher like Miguel Montero or Brian McCann has a gripe about the strike zone, it’s usually safe to side with the catcher.

And if Rob Manfred is really concerned about speeding up the game, he shouldn’t even bother putting an ump behind home when Buster Posey is catching.

But does being in a squat for an hour and a half for 100 games a year actually help catchers when they rotate 90 degrees and trade their glove for a bat?

In 2014, FiveThirtyEight writer Neil Paine published an article titled, “The Most Disciplined MLB Batters.” Looking at qualified batters, Paine coins the statistic, “Good Decision %,” (GD%) which consolidates FanGraphs’ plate discipline data into a single percentage to determine how often a hitter made a “good decision.” i.e. swung at a strike or didn’t swing at a ball. Using Paine’s formula, here are the best decision makers in baseball from 2014 to Apr. 21, 2017.

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The results aren’t exactly favorable for catchers. While three make their way into the top 10, they are accompanied by four first baseman (counting John Jaso as both a catcher and first baseman), three outfielders, and one Lowrie lonely infielder. 

However, the data might not be telling the whole story. 

Paine’s original methodology only examined qualified batters. Since the 162 game schedule was implemented in 1962, no catcher has ever played every game of a full season. Meanwhile, there have been 249 instances of players at other positions playing at least 162 games in a season. In the past five years, the closest any catcher has ever come to a full 162 was Salvador Perez in 2014 when he played 143 games behind home. The following spring training Ned Yost announced that he was going to make a point to play Salvy less to curb the chance of injury; and by 2016, Yost had reduced Perez’ workload by almost 13% (1248.2 innings down to 1105.2). So while the qualified batter metric is useful for omitting small sample sizes and consequently misleading results, it can exclude catchers who have trouble accumulating 3.1 plate appearances per team game.

Here then, is what the top 10 looks like if the bar of entry is lowered to (around) 250 PAs per season in the same timeframe.

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Entering the top 10 are Alex Avila and Nick Hundley, who, in addition to being high up on the list (third and fourth, respectively), also bring the number of catchers in the top 10 to five — half the list!

While top 10 lists are useful for giving a 30,000-foot snapshot, and generating ad revenue, they usually don’t indicate how the field as a whole is doing. In the case of plate discipline, outside of the top 10, catchers are few and far between as opposed to being clustered near the top — as you would expect if there was something innate about the position and good discipline. And looking at Fangraphs’ plate discipline data back to 2002 reveals that catchers, historically, are pretty normal.
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So, if catcher helmets aren’t leaking a mysterious radioactive material that improves eyesight, why are half of the game’s most disciplined hitters catchers? Well, blame Chris Iannetta.

From 2011-2016, Iannetta maintained the best GD% in baseball at 74.84%. That’s right, Chris Iannetta, he of the .282 wOBA in 2016, was the most disciplined batter in baseball. Not Joey Votto, Dexter Fowler, or Brandon Belt. Chris Iannetta.

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In that six-year span, he’s been one of the top three decision-makers every year, while only two other catchers, Alex Avila and Nick Hundley, have made appearances in the top five more than once. In other words, Chris Iannetta is an outsider’s outsider, and ignoring him leaves catchers as, once again, pretty normal within the scope of the top 10: four catchers, four first baseman (Jaso counting as both a first baseman and catcher), and three outfielders.

Additionally, 2017 is indicating that the days of Chris Iannetta: Most Disciplined Batter In Baseball™ may be over. So far, Iannetta has a 74.62% GD% — right in line with his career numbers. But while Iannetta remained the same, the rest of the league has improved significantly. Good Decision % is up by almost a full percentage point across the board compared to 2016, and while Iannetta is still posting the best GD% among catchers, he is currently 24th in baseball. The number one ranked Lonnie Chisenhall, and the number two ranked Joey Votto have both posted GD%’s north of 80%.

As plate discipline plummeted around 2009, catchers like Chris Iannetta, Alex Avila, and Nick Hundley emerged as some of the most disciplined hitters in baseball — perhaps thanks to weak competition. With “Good Decision %” numbers on the rise again, however, catchers have faded in with the crowd. While five of the 10 most disciplined hitters from 2014 to 2016 were catchers, it’s unlikely that there’s anything unique about the position that makes it inherently easier to recognize a pitch as a strike or a ball out of the pitcher’s hand.

Edited by Emily Berman, Coleman Gray.

Who has caught the most innings in MLB since 2010?
Created 4/26/17
  1. Buster Posey
  2. Russel Martin
  3. Yadier Molina
  4. Jonathan Lucroy

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