Is It Time for Robot Umps?

As much as I’m in favor of maintaining the game’s human element, I’m getting really sick of the amoeba strike zones we’re seeing with what appears to be increasing regularity. I’m sure some of that has to do with a greater focus on and understanding of pitch framing, not to mention access to zone maps like the ones you’ll find below from Brooks Baseball. It figures that the more closely we scrutinize anything, the more issues we’ll find. As such it’s entirely likely that umpires haven’t been getting worse, just that we can see their flaws more clearly.

That does not mean, however, that we should just shrug it off because that’s the way it’s always been. If that was the way the rest of life worked, you’d still be able to smoke on airplanes and put your kids in rear-facing station wagon jumpseats. Instant replay hasn’t exactly been embraced by fans, but that’s more a matter of it taking too much time than of getting the calls right.

If MLB really wants to cultivate new fans while continuing to satisfy existing ones, where better to start than by standardizing ball and strike calls? Not only would you mitigate some of the griping from players, managers, and fans, but you’d likely end up increasing scoring as well. You see, this isn’t just about hitters getting rung up on called third strikes, though that is certainly a part of the issue. An expanded strike zone forces hitters to protect and swing at pitches they might have otherwise taken, resulting in swings and misses or poor contact.

I understand that it’s irresponsible to base an argument on three games, but I found myself constantly criticizing the amorphous zone during the Cubs/Cards series and wanted to take a closer look at whether my complaints were rooted in fact. I order to do that, I’ve included zone maps from the three games in St. Louis so that we can do a quick breakdown of each.

First, a quick primer on how to decipher the charts:

These graphs…only plot balls and called strikes [emphasis mine]. No other pitches or results are included. Intuitively, this provides a representation of the strikezone for each game.

Each pitch is represented by a single dot. Green dots are balls and red dots are strikes. Pitches marked as belonging to a particular team (“sln” for the Cardinals and “chn” for the Cubs) are designated with different shapes. These teams represent the pitching team, not the batting team.

These are from the Umpire’s perspective, not the Pitcher’s perspective.

These strikezone maps are now [sic] drawn to reflect the 2015 zone “as called” to LHH and RHH hitters. These strikezone maps were drawn to the specifications of Mike Fast, a former writer for Baseball Prospectus who now works for the Houston Astros. These plots show actual calls superimposed onto dashed lines that represent the strikezones that all Umpires generally call. The dashed lines shift to represent typical deviations for LHH and RHH.

First up is Monday’s game, in which John Lackey opposed Mike Leake with Carlos Torres behind the plate. What I’m going to be looking for is pitches outside of both the ideal and called strike zones that were called strikes and pitches in the zone(s) that were called balls. Have a look and we’ll discuss below.



The first thing that jumps out here is how many more calls there were against left-handed hitters, but that makes sense with two righties on the mound. Of the 61 calls made with lefties at the plate, none were incorrectly called balls. Seven, however, were outside the zone and were still called strikes and only one of those fell inside the dashed line representing the zone generally utilized by umpires. The Cubs got the benefit on only two calls, though Lackey is known as a strike-thrower and was inducing a lot of swings to boot.

Torres appears to have been pretty spot-on against right-handers (only four calls outside the hashed zone), giving him an overall error rate of 10.5 percent. That accuracy is actually pretty remarkable when compared against some of the statistics on “incorrect” calls in general. Let’s see if that trend continued to the next game.



Gerry Davis was behind the plate on Tuesday and the calls were significantly worse than they’d been the previous day. By my count, 13 pitches to LHH were improperly called strikes and five more called balls according to the ideal zone. Even if we eliminate borderline pitches, we’re left with 13 total incorrect calls. For what it’s worth, nine of those (eight called strikes and a ball) favored the home team, including all four strikes that fell outside even the zone umps usually call.

Things were a lot cleaner against RHH, as Davis only got 10 calls wrong. Even so, he appears to have missed badly on some pitches at the lower end of the zone and every one of the called strikes benefited the Cardinals, though the balls were more even. If we look only at the balls that were clearly outside of the hashed lines, Davis was only incorrect about 11.8 percent of the time. If, however, we use the ideal strike zone and don’t include borderline calls, that jumps to 16.8 percent. And there were another eight pitches that could have gone either way.

Finally, we come to the rain-delayed marathon on Wednesday.



By my count, Sam Holbrook made 22 incorrect calls (17.9%) either way you slice it, though the breakdown is really interesting. His mistakes with lefties at the plate were in calling balls strikes, but the trend was reversed against righties. Looking at how the calls are scattered, it would appear that he’s more a fan of pitches up and out. Also notable is the fact that seven of the 11 strikes that were called balls against righties (according to hashed zone) went against the Cubs.

Again, this is much too small a sample from which to draw definitive conclusions — if it’s large samples you seek, this FiveThirtyEight piece about umpires’ tendencies from Etan Green has you covered. Either way, the results above are indicative of a pervasive issue in Major League Baseball. Umps might actually be better and more consistent now than in the past due to the same scrutiny that makes us question them, but that doesn’t mean they’re best equipped to make calls on pitches that are being thrown harder than ever.

But what to do about it? I’ve mentioned before that I don’t believe umpires should be replaced altogether, but that they should be given a little electronic assistance. The most viable solution I’ve been able to come up with so far is through the use of heads-up eyewear equipped with a strike zone map. It’s non-invasive and the technology exists and would simply need to be retro-fitted for baseball.

What do you think, dear reader? Do you want as much accuracy as possible or do you prefer your baseball with a healthy side of human error? At the end of the day, that’s what this comes down to, really. It’s all about what the fans want. So what do you want and how would you change things one way or the other?

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