The Automated Zone in Triple-A Has Rookies Like Ben Brown Pumping Strikes in MLB

[Matthew Trueblood]

It's frightening to imagine where the Chicago Cubs' starting rotation would be, if not for their slender right-handed rookie starter. His stuff has always been good, but it's been impressive to see him throw so many strikes in his first bite at the big-league apple. He's far from alone in that regard, though.

Image courtesy of © Albert Cesare/The Enquirer / USA TODAY NETWORK

It's not shocking that Ben Brown has struck out nearly 29 percent of the batters he's faced in his first ride of the senior circuit. Although he only has two pitches on which he can consistently rely, they're two devastating offerings: a fastball that sits 96-97 and touches 99 miles per hour, and a power curveball that looks just like that heater to overwhelmed hitters.

Much more surprising, though, is the fact that Brown is throwing strikes enough to rack up those strikeouts, and to keep runners from piling up on the bases. His walk rate is 8.8%, which is a hair worse than the league average, but it's felt more like a matter of feeling, testing, and trying to induce chases on close pitches than like a young hurler who ever loses contact with the zone. Because he doesn't have a third pitch with which to change lanes and force hitters to become more defensive, Brown has to try to prey on their aggressiveness. That's led to a few walks, but those walks are almost salubrious; they're necessary to threading the needle and getting strikeouts without giving up hard contact.

For a pitcher with stuff as intense as Brown's (but also a spotty track record of strike-throwing in the minors, as Brown has), even average control is immensely valuable. He's thrown 84.6% of his pitches within 18 inches of the center of the strike zone, which constitutes a competitive pitch. That's almost exactly the league-average mark for pitchers who have faced at least 100 batters. He's throwing 90.4% of his fastballs in competitive locations, a full percentage point better than the league's average for four-seamers.

Without a doubt, the Cubs and their young pitcher each deserve credit for that. Brown has had to work hard to get his control and command to this point, given the velocity with which he attacks on both pitches, his injury history, and the fact that control didn't come easily to him. As recently as last season, Brown looked too wild to merit a call-up to the big leagues. After being promoted to Double-A upon the Cubs trading for him in mid-2022, Brown walked 9.3% of opposing batters at that level between the second half of that year and the early part of 2023. When he went to Triple-A Iowa last summer, he walked a ghastly 16.2% of opponents.

That was the key moment, though, because it was in Iowa that he was subjected to an automated strike zone--and forced to learn to drop the ball on the head of a pin. The Triple-A strike zone is shaped by technology, with two different modes of umpire assistance in force at different times during the weekly cycle of games. The computers believe umpires have been far too generous over the years. The zone at the highest level of the minors is minuscule; the global walk rate is 11.4% this year. Last season, it was an even more unseemly 12.0%.

Those zones are, overall, bad for development, and they make for bad baseball. They're a superb reminder that we're not especially close to being ready to have robots call strikes for the best hitters and pitchers in the world. However, there's one redeeming caveat at play: Triple-A has become a crucible in which pitchers have to withstand severe heat and pressure, and the ones who survive it and matriculate to the majors have unusually good control by the time they come up.

As you would guess, historically, rookies have been a bit more scattershot than the average pitcher when they arrive in the majors. These are guys who were in the minors, until now, for a reason, and for many of them, that reason is a dearth of control. They're trying to adjust, they're trying to handle the mental challenge of pitching in the big leagues for the first time, and they're working against a lack of reputation-driven help from umpires. In general, they throw fewer strikes, and have more bad misses than more experienced hurlers.

Balls and strikes came under the direct influence of the machines in Triple-A at the start of 2023. Since then, we've seen a sharp change in the ability of rookies to throw strikes.

Zone Rate and Competitive Pitch Location %, MLB Rookies, 2015-24

Season	Zone %	Comp Loc %
2015	48.7	83.5
2016	48.8	83.8
2017	49.9	84.6
2018	49.3	83.8
2019	47.9	82.9
2021	49.3	83.3
2022	48.9	83.3
2023	50.2	84
2024	51.1	84.7

Since the advent of the very strict computerized zones, rookies have had to wriggle through an unforgiving bottleneck to reach the majors. The only ones who do so are those who prove at least able to bite at the edges of the zone--and ideally, to consistently pound it with quality strikes. Brown is impressive, but he's not special. Right now, he's just another of several examples of pitchers who had to pass a more rigorous test to reach the majors than they had until last season.

Again, overall, these non-human zones are bad for the game. Hitters matter, too, and if you're wondering why guys like Matt Mervis can put up such gaudy numbers in Triple-A but fall flat upon coming up to the big leagues, look no further than this very thing. Nor is having to fill up the zone or risk a great many walks the best way to develop many pitchers. Brown belongs to the class of those who have benefited greatly from this change, though. He just needed the control to tap into the ferocity of his stuff, and with each solid (and occasionally dominant) start he makes for the Cubs, we should all be reminded that his ruthless robot trainers helped mold him into this caliber of hurler.

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