The Automated Ball and Strike System (ABS) made its big league debut Thursday, February 20. The debut will be short-lived — approximately 60 spring training games. But its return to MLB ballparks, hopefully as early as the 2026 season, is both inevitable and necessary.
The system being field-tested this spring awards each team two challenges, the teams retaining a challenge if they succeed in overturning an umpire’s ball-strike call. In the system’s Thursday debut, in a game between the Los Angeles Dodgers and Chicago Cubs played at Camelback Ranch, the system was employed only modestly.
With the Cubs winning that game comfortably 12-4, only two challenges were signaled, both by Chicago. In the first inning, pitcher Cody Poteet challenged plate umpire Tony Randazzo’s call of a ball below the strike zone to Max Muncy on an 0-1 count.
Within seconds, the ABS system reversed Randazzo’s call to a strike at the knees, changing the count from 1-1 to 0-2. Muncy eventually struck out.
The Cubs challenged a call using the ABS system.
— Marquee Sports Network (@WatchMarquee) February 20, 2025
Cody Poteet's pitch was overturned from a ball to a strike. pic.twitter.com/3glq7l1sRx
Then, in the eighth inning, with the outcome long decided, non-roster catcher Pablo Aliendo challenged a Randazzo ruling that a Frankie Scalzo pitch to Seth McClain caught the top of the strike zone. Again within seconds, the ABS system ruled, this time confirming Randazzo’s ball two call, finding that the pitch had been 1.6 inches high. McClain eventually walked.
Overall, it was a conservative and non-controversial debut for the system: two reviews, both quickly dispatched, neither markedly impacting the game’s outcome. The impact, however, lies not in the usage, but in the system’s validation of its existence.
Wrong umpire calls are simply unacceptable in modern MLB
In both cases, ABS righted a wrong and did so with noteworthy dispatch. While MLB has already declared that its spring use will not be extended into the 2025 regular season, its return at some point — possibly with formulaic tweaks — is inevitable.
Two reasons why that is so. First and most important, in a replay-rich age in which big gambling money hangs on the outcome of every pitch, fans are intolerant of umpire error. That’s why football, basketball, hockey and baseball have all incorporated replay review into numerous aspects of their games.
It is simply no longer acceptable that games could be decided by an official’s error.
One of the few remaining exceptions to that dictum is the sanctity of the umpire’s ball-strike prerogative. But that leads to the second reason why the arrival of ABS is inevitable. Increasingly, the reality is taking hold that incorrect ball-strike calls are likely the most damaging official errors not yet considered correctible.
The data on this is public and massing. We know from official MLB data and/or from SABRmetric sources that the following two statements are, with minor game-to-game variations, true.
1. Plate umpires make about 150 ball-strike calls during the course of a game, and get about 92 percent (on average 138) of them right. That means they’re wrong about a dozen times per game.
2. When an average big leaguer puts a 2-1 pitch in play, he hits about .344 with a .583 slugging percentage. When that same hitter swings at a 1-2 pitch, his average is .166 and his slug is .255. Those are changes of 178 and 328 percentage points, respectively.
Is it clear why it’s so important that an umpire’s ball-strike call on a 1-1 count is so vital?
Our first instinct is to go back to fact 1, that umpires on average get about 92 percent of calls right, and ask "what’s the problem"? Part of the answer lies in fact 2, but another part is this: The vast, vast majority of those 150 ball-strike calls per game are elemental. They are pitches in the dirt, very high, wide or inside, or strikes taken right down the middle.
Peruse game-by-game results on MLB.com and you will come to the mathematical judgment I came to some years ago: that about three-quarters of those 150 calls are virtually unmissable by anybody with a rudimentary understanding of the rules.
So we’re not really talking about 150 calls per game, but instead about the 25 percent (37.5 pitches) that might theoretically be missed. And that turns the functional umpire miss rate from a minuscule 8 percent as touted by MLB and the umpires association to something approaching one-third (12 of 37.5). That’s significant.
And when those errors occur in critical situations, the umpire’s error puts the victim — whether it be the batter or pitcher — in a deeply and unfairly disadvantageous situation.
That being the very integrity of the game is why the ABS system can’t be institutionalized soon enough.