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An automated strike zone was used in some Arizona Fall League games

Here’s what players thought.

Photo by Joshua Sarner/Icon Sportswire via Getty Images

There have been bad ball-and-strike calls since the beginnings of baseball.

These are magnified in the modern era due to high-definition television and the strike-zone box featured on many broadcasts. To be fair, that box isn’t necessarily 100 percent accurate in describing the strike zone. What it has done, though, is increase the call for an automated strike zone. MLB has enough cameras in ballparks to accomplish this goal.

What they are doing, I think, is approaching this the right way. Instead of simply instituting automated ball-and-strike calls with a system that might not be perfect, MLB is testing this system. They have a three-year agreement with the independent Atlantic League to do so, and during the just-completed Arizona Fall League, an automated ball-and-strike system was installed at Salt River Fields. That park was home to two of the six AFL teams, so that means one-third of the entire league’s games used this system, a reasonably large sample size (30 of the 90 games played).’s Jonathan Mayo spoke to several AFL players to get their reaction to this system.

“Inside and outside pitches are pretty well done,” said Twins top prospect Royce Lewis, who played the fall season for Salt River. “I think up and down is the only part where they’re trying to figure it out. A curveball might break at the top late and catch the top part of the zone. It also might break early and catch the bottom part of zone. I think that’s some of the things that need adjusting. I’m sure someone’s smart enough to figure that out, just not me. I’m sure it’ll be figured out soon.”

Lewis’s comment echoes a sentiment heard from numerous people we spoke to. Curves that clip the top or bottom of the zone haven’t traditionally been called strikes by umpires, especially if they end up in the dirt, but they are technically strikes by the rule book. Players and fans saw this dynamic come into play when Giants outfield prospect Jacob Heyward, the younger brother of Cubs outfielder Jason Heyward, got ejected after voicing his displeasure about a called third strike from ABS.

Here’s the pitch where Jacob Heyward was ejected:

Jonathan Mayo’s article contains this graphic that shows that pitch was indeed a strike:

You can see the issue here, I think. The strike zone box you see on a TV broadcast is one-dimensional, but the strike zone is three-dimensional. You’ll note that the pitch thrown appears — by the graphic taken from Gameday — does indeed touch the corner of the strike zone. That’s a rule-book strike.

And right there, you see the difference in the argument between those who want “robot umpires” (I’m one of those) and those who want “the human element.” It’s nearly impossible for a human being to determine the corner of the rule-book strike zone, standing/crouching behind the catcher. But the strike zone is clearly defined, as noted in Mayo’s article:

“The strike zone is that area over home plate, the upper limit of which is a horizontal line at the midpoint between the top of the shoulders and the top of the uniform pants, and the lower level is a line at the hollow beneath the kneecap.”

“That area over home plate” is the key phrase there. Home plate isn’t just a flat plane defined by the box you see on TV. It’s a three-dimensional zone. In the case of the pitch you see above, it was thrown in such a way to just get the corner of the zone while appearing to the hitter to be out of the zone. (Whether the pitcher was able to put that pitch right there deliberately or whether this was a fortunate accident on his part is another story entirely.)

And that, writes Mayo, is the issue MLB still has to deal with:

Major League Baseball will also adapt based on feedback received during this experiment, which has been perceived as largely successful, with the technology working well. One thing to be discussed is where to set the strike zone on the system so it will most fairly call balls and strikes.

“Most fairly” means this, said Royce Lewis:

“With that zone, I think they are technically strikes or they’re clipping the zone, but as far as human nature … an umpire that’s human would realize that’s not a hittable pitch for someone that’s throwing 98 and has a breaker at 80, like Justin Verlander, or someone that’s just unhittable, and that wouldn’t be fair to the hitters,” Lewis said. “I think with the robo-ump, that’s the only part they can’t distinguish yet. Whatever they do, I’m sure it’ll be better.”

So there’s the issue with setting up the robo-umps so they call the rule-book strike zone. There are, as Royce Lewis notes, pitches in the rule-book zone that are not “hittable.” Should those be called strikes? There’s a reasonable argument that they should be, because otherwise — why are they strikes? Perhaps this is an argument for adjusting the rule-book strike zone itself. That’s actually something that has been done multiple times in major-league history:

The official strike zone is the area over home plate from the midpoint between a batter’s shoulders and the top of the uniform pants -- when the batter is in his stance and prepared to swing at a pitched ball -- and a point just below the kneecap. In order to get a strike call, part of the ball must cross over part of home plate while in the aforementioned area.

Strikes and balls are called by the home-plate umpire after every pitch has passed the batter, unless the batter makes contact with the baseball (in which case the pitch is automatically a strike).

History of the rule

The vertical specifications of the strike zone have been altered several times during the history of baseball, with the current version being implemented in 1996.

Past strike zones

From 1988-95, the strike zone went from the midpoint between the shoulders and the top of the uniform pants, to the top of the knees.

From 1969-87, the strike zone went from the batter’s armpits to the top of the knees. This strike zone was implemented, along with the lowering of the mound from 15 inches to 10 inches, in response to a 1968 season -- now known as the “Year of the Pitcher” -- in which the dominance of hurlers reached new heights.

From 1963-68, the strike zone went from the top of the batter’s shoulders to the knees.

From 1950-62, the strike zone went from the batter’s armpits to the top of the knees.

The version of the strike zone used from 1963-68 was also utilized prior to 1950, going back to the late 1800s.

So this is something that clearly could be tweaked until MLB gets a zone that is fair to both pitchers and hitters as well as something that could be called properly by a system with cameras and computers.

Here’s an interesting article by a writer who was allowed to test the Atlantic League’s system during a bullpen session this past August. He appears to lean toward not having such a system, but provides the arguments both pro and con, worth reading.

Since the MLB/Atlantic League experiment still has two years to go, I would not expect any change to an automated zone at the major-league level until it’s over. The end date of that deal coincides with the end of the collective-bargaining agreement between MLB owners and players, so it’s possible that could be part of the negotiations for a new CBA after the 2021 season.

In the meantime, I’m going to repeat the modest proposal I posted here in August — allow each manager two ball-and-strike challenges per game (and no extra ones even if the challenge is correct). In practice, with only two such challenges, managers would likely save them for the most egregious missed calls, and it wouldn’t slow games down too much.

To those who want “the human element” regarding ball-and-strike calls, I would argue that the “human element” ought to be what the players actually do, not what one guy standing behind home plate thinks the players did. Let’s get the calls right, or at least as many as it’s... humanly possible to get right.