The White Sox’ Hidden Catastrophe

I was reading through Jon Heyman’s latest Inside Baseball, and then I got to the White Sox section. Within, Heyman said something about Chris Sale, and though it wasn’t specifically about everything that’s going to follow in here, it at least works well enough for me to embed:

Chris Sale’s pitches come from such an unusual angle, it seems to fool umpires. It looked like he had an 0-and-5 count on Nick Castellanos in one at-bat (the actual count was 3-and-2)

Nothing important, really. Just a fleeting thought about one at-bat in particular. OK! Well, as you know, balls and strikes have to do with multiple factors. The pitcher plays a part. The hitter plays a part. The umpire plays a part. Dumb luck plays a part. And the catcher plays a part. In some previous posts, I’ve quickly touched on the White Sox’s catchers. It seems time for something in greater depth, because this has been an awfully big problem for a team that’s badly slipped.

Last year’s White Sox were backstopped by Tyler Flowers. Led mostly by him, White Sox catchers combined for a 79 wRC+. Come the offseason, they made the decision to exchange catcher defense for catcher offense, adding both Alex Avila and Dioner Navarro. Neither is Flowers behind the dish, but Rick Hahn wanted some bats. To this point, White Sox catchers have combined for a 74 wRC+. So.

It’s bad enough the offense hasn’t improved, but the defensive downgrade has been substantial. Not in every single area, perhaps, but my focus is on the strike zone. I’ve written previously that the White Sox have pitched to the least favorable strike zone in the majors to date. That’s something I approximate using numbers readily available on our leaderboards, and it falls mostly on the receivers. I wanted to get some greater context, so I calculated numbers going back to 2008, which was the start of the PITCHf/x era. Relative to the rest of the current landscape, the White Sox are almost in the nine-year basement.

A word on the method before the table: For every team-season since 2008, I calculated strikes minus expected strikes, normalizing the average to zero. Then for each league season I calculated the standard deviation among the 30 teams, and at that point I could calculate a z-score. Every team got a strike-zone z-score, and here are the bottom 10. Hopefully this is clear enough. Teams shouldn’t want to be in this table, basically.

Worst Team Strike Zones
Team Season Zone z-score
Pirates 2008 -2.2
Indians 2011 -2.2
Twins 2013 -2.2
White Sox 2016 -2.0
Twins 2014 -2.0
Tigers 2015 -1.9
Marlins 2013 -1.9
Pirates 2009 -1.8
Tigers 2009 -1.8
Mariners 2010 -1.8
2008 – 2016.

This year’s White Sox are at two standard deviations worse than the league average. That’s not the worst mark in the table — they’re eclipsed by the 2008 Pirates, the 2011 Indians, and the 2013 Twins. But then, that’s also some lousy company, and it’s not like those teams are beating out the White Sox by much. Standard deviation is only one way of measuring this, and maybe you’d prefer something else, but no matter what you do, the takeaway remains the same: The strike zone hasn’t been friendly to White Sox pitchers, and pitchers want friendly strike zones.

Especially when they get used to friendly strike zones. Part of what makes this so stunning is that last year the strike zone was somewhat generous. So the Sox haven’t gone from average to bad — they’ve gone from good to bad. Flowers was a quality receiver. Geovany Soto was a quality receiver. They’re gone! You’ve seen, now, some single-season z-scores. Now let’s make it even more complicated and look at successive season z-scores. Here are the biggest year-to-year drops between 2008 – 2016 so far:

Worsening Strike Zones
Team Seasons Y1 z Y2 z Change
White Sox 2015 – 2016 1.9 -2.0 -3.9
Mariners 2015 – 2016 0.6 -1.5 -2.1
Diamondbacks 2014 – 2015 1.7 -0.2 -1.8
Yankees 2009 – 2010 0.4 -1.3 -1.6
Blue Jays 2013 – 2014 0.5 -1.0 -1.5
2008 – 2016.

Last year, the White Sox strike zone was almost two standard deviations friendlier than average. This year, as you know, has been the opposite, and so the difference is right near four standard deviations. Which you can tell is ridiculous when you see that second place is just about half that, in magnitude. I’m sure this year’s Mariners have felt it, too, but they have nothing on the White Sox, so at least they’re not in the cellar. This change has been abrupt and dramatic. It’s not a nice thing to have happen to your pitchers, as talented as they might be.

Where has the White Sox strike zone gotten worse? With the help of Baseball Savant, I prepared the following image. On the left, you see zone breakdowns and identifiers. On the right, you see the year-to-year changes in called-strike rate, with total called pitches as the denominator.


The zone hasn’t gotten worse everywhere. Far from it, in fact. The Sox have been getting more called strikes up high, relative to last season. It’s suggested that Flowers and Soto were setting lower targets, while Avila and Navarro are working higher. But the differences at the bottom are big, as that’s where more pitches go. The White Sox have lost the bottom edge of the zone, and they’ve lost strikes just off the boundary. If you just compare all this year’s rates to last year’s rates, you have a difference of more than 130 strikes. Which would be something on the order of 20 runs, here before the midway point of the regular season.

The White Sox zone has probably felt squeezed, and it’s definitely been squeezed down low. I’m not going to say that’s fair or unfair, but it’s what’s happened, due mostly to intentional decision-making. They knew they were giving up defense; they just expected more offense. When the hitting isn’t there, it’s all just a mess. I want now to include one more table. This one comes courtesy of StatCorner. There, for each pitcher, you can see the rate of taken pitches in the zone called balls, and you can see the rate of taken pitches out of the zone called strikes. I created a quick little strike-zone statistic, which adds the latter rate to 1 minus the former rate. The higher the number, the better the zone for the pitcher in question. I looked at every pitcher who’s thrown at least 1,000 pitches in each of the last two seasons. Then I sorted by the biggest drops in this strike-zone statistic. I know it’s kind of weird, but, here you go:

Pitchers Getting Worse Zones
Pitcher Team 2015 Z+O% 2016 Z+O% Change
Martin Perez Rangers 101% 88% -13%
Chris Sale White Sox 100% 87% -13%
Nate Karns Mariners 98% 87% -11%
Carlos Rodon White Sox 90% 80% -10%
Jose Quintana White Sox 100% 91% -9%
Mat Latos White Sox 99% 90% -9%
Hisashi Iwakuma Mariners 97% 88% -8%
Kendall Graveman Athletics 97% 88% -8%
Jeff Locke Pirates 99% 91% -8%
Mike Pelfrey Tigers 95% 88% -7%
SOURCE: StatCorner

There are four qualifying White Sox pitchers. They’re all in the bottom six, along with Perez and Karns. I know that Latos is gone, but he was in Chicago long enough. So this isn’t just a matter of the White Sox having pitchers who might be more difficult to receive. Latos this year pitched to a worse zone. Same with Quintana. Same with Rodon. Same with Sale. They’ve probably all noticed, or they’ve probably all at least felt like something’s been up. The numbers all point in this direction, and it’s not doing the White Sox any favors.

On Thursday, Avila was good for four hits. As long as the catchers are good for four hits, the White Sox’ll love them. If the bats actually show up and produce as much as the White Sox thought they would, this might be tolerable. As is, this has been a big problem, and it doesn’t help matters that the organization might not have what it would take to pry Jonathan Lucroy from the Brewers. He’d be the ideal fit, but there’s simply not a lot left, not to get an affordable star-level catcher. So maybe it’s about another option, or maybe it’s about hoping for an offensive surge. To this point, the catching position has been a wreck. The improved offense hasn’t resulted in improved offense, and the strike zone has been terribly stingy. Worse zones make all pitchers worse pitchers.

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Jeff made Lookout Landing a thing, but he does not still write there about the Mariners. He does write here, sometimes about the Mariners, but usually not.

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Can’t be a coincidence that 2 of the teams in the “worsening strike zone” charts included Navarro getting a significant # of PA. Jays in 2013-2014 went from Arencibia (a terrible player, but decent framer, apparently) to Navarro. White Sox in 2016 gave the bulk of the catching duties to Navarro as well.

Granted, Navarro at least hit well for the Jays in 2014 so that offset the horrible framing a bit, but he’s not hitting, and not fielding at all for the White Sox.


And Avila was a part of the 2015 Tigers squad that also show up on the list.