If you've been watching baseball over the last three weeks, you probably already know the basics. The Automated Ball-Strike Challenge system is in, it's working, and watching a called strike flip to a ball on a stadium scoreboard while 40,000 people lose their minds is genuinely great television. The novelty hasn't worn off yet, and for most fans the conversation has stayed right at the surface: robots are here, umpires are having a tough time, and the game is better for it.
But if you dig into the early data, there's a more interesting question lurking underneath all of that: who is actually good at this?
Three weeks and 1,029 challenges into the 2026 season, Baseball Savant's ABS leaderboard is starting to give us a real answer, and it's pointing pretty clearly at one position.
Methodology note: all data comes from Baseball Savant's ABS Challenge Leaderboard as of April 15, 2026. "Win%" refers to overturn rate: the percentage of challenges that resulted in a call being reversed. "Net overturns" is wins minus losses. Challenge rate is the percentage of eligible pitches actually challenged, defined as takes that went against the challenging team with challenges remaining.
Part 1: The Setup
Before we dive into the details, it is worth acknowledging the basics. In any given at bat there are three types of players can initiate a challenge: batters, catchers, and pitchers. Each of them has a two-second window after a call to tap their helmet or hat, at which point Hawk-Eye (a computer vision system used to visually track the trajectory of a ball) renders its verdict on the scoreboard. Each team starts the game with two challenges, keeps them on a successful overturn, and loses them on a failed one. On paper it's a level playing field - the same system, the same time window, the same stakes for everyone involved. Which is what makes the disparity in overall success rate across these respective cohorts so striking.
Pitchers have only challenged 21 times across the entire early season, so their sample is too thin to read much into. But both batters and catchers have each challenged roughly 500 times, which makes the 14-percentage-point gap in success rate between them a meaningful signal, and a thread worth pulling on.
Part 2: It's All About The Catchers
When ABS was announced, plenty of ink was spilled on the strategic question of when to challenge and who should be doing it. On the positional question the data is already telling a pretty clear story. Catchers see every single pitch, they've spent their careers reading locations and calling games, and they're 60 feet closer to the plate than the pitcher is. Batters, by the very nature of their job, are wired to be aggressive: faced with a close call, they want to stay in the box, and that instinct probably leads to more emotional, less disciplined decision-making when it's time to tap the helmet.
Pitch framing, the skill everyone assumed would become obsolete when robot umps arrived, turns out to be exactly the cognitive toolkit ABS rewards. The best framers are the ones who know, in real time, whether a pitch caught the corner or just missed it. That instinct doesn't disappear when Hawk-Eye shows up - it just finds a new context to matter in.
The individual catcher leaderboard helps drive this point home. Among catchers with at least four challenges, all but four are sitting above a 50% success rate - taken as a group, catchers are more often right than wrong. J.T. Realmuto and Mitch Garver are both at 100%, Dillon Dingler is at 82% across 11 attempts, and Danny Jansen is converting at 86% on seven challenges. Work your way to the right side of the chart and the picture does get uglier: Shea Langeliers and Samuel Basallo are both sitting at 40% or below, and one might reasonably argue that Edgar Quero (7-for-20, 35%) should be relieved of his helmet-tapping duties for the foreseeable future. But those are the exceptions. The position as a whole is making the right call, and making it consistently.
Part 3: Being Great on One Side Tells You Nothing About the Other
The natural follow-up question is whether the teams winning the defensive side of this are also winning the offensive side. The answer is broadly no, and the degree of the mismatch is worth illustrating.
If you’re looking at this and wondering “what’s the correlation”, you’re asking exactly the right question. There really isn’t one. Milwaukee's catchers are winning 67% of their fielding challenges, but their hitters are winning 27% of their offensive challenges - a 40-point gap that is the largest of any team in baseball. Detroit is at 86% defensively and 48% offensively. Seattle is 68% defensively and 35% offensively. Philadelphia is 79% defensively and 47% offensively.
ABS prowess, at least at the moment, doesn't appear to be something that can simply be coached into a lineup. Rather, it likely comes down to the individual player(s). Said differently, just because you have a catcher that sees the zone well doesn't mean your lineup will do the same. Cincinnati is the one genuine outlier, sitting at 69% offensively and 73% defensively, good on both sides of the ledger. For everyone else, the two leaderboards are essentially independent.
Which raises a related question: within the defensive side of ABS, are teams with the highest win rates actually extracting the most value from the system? It turns out win rate alone doesn't quite capture it.
Part 4: The Importance of Precision and Situation
Here's the thing about the catcher leaderboard that gets lost in the win percentages: it doesn't just matter how often you're right, it matters whether you're challenging pitches that were worth challenging in the first place. Baseball Savant's Team Summary view gets at this through their "Total vs. Expected" metric, which compares actual overturns to what a model would predict given pitch location, game situation, runners on base, and remaining challenges. Put simply, it rewards teams for challenging smart, not just challenging successfully.
Source - Baseball Savant
Through that lens, the leaderboard looks a little different. Miami sits third overall despite a win rate of 55% - they're challenging in spots where the expected value is high, and it shows. Compare that to the Athletics and Cleveland: both are sitting near the bottom five in Total vs. Expected despite carrying a similar win rate to Miami on the season. Winning challenges isn't enough if you're burning them on pitches where the count situation doesn't move the needle much either way.
This is also where the conversation around ABS is likely to evolve as the season goes on. Teams are still calibrating. As players get more familiar with the system, the low-leverage challenge - the borderline first-pitch call with nobody on in the second inning - should start to disappear. The reward in that situation simply doesn't justify the risk of burning a challenge you might desperately need two hours later. The teams that figure that out fastest will start separating themselves on this leaderboard, and probably on the scoreboard too.
Part 5: A Brief Word on Pitchers
Twenty-one pitcher challenges have been attempted all season, no pitcher has tried more than once, and of those 21 attempts exactly 10 were successful. The league figured this one out fast: the person standing 60 feet away, emotionally invested in escaping a jam, is not the right person making a split-second call on a pitch they just threw. Teams have quietly and collectively moved on from this option, which is the correct move.
The Takeaway
The irony of the ABS era is that it was supposed to slowly make pitch framing obsolete. The argument made sense on paper: if a computer is calling the pitch, the ability to deceive an umpire with your glove work becomes less valuable. However, the cognitive core of framing - knowing exactly where the zone ends in real time - turns out to be exactly what the challenge system rewards.
Three weeks isn't enough data to crown anyone, and these leaderboards will look meaningfully different by July. But the directional signal is already clear: in the ABS era, the catchers who are good at it are providing real and measurable value, and the ones who aren't are costing their teams in ways that now show up in the data every single day.
If you want to track how this unfolds over the rest of the season, Baseball Savant's ABS Challenge Leaderboard updates daily and is worth bookmarking. And if you're thinking about how early-signal analysis like this applies to the data in your own business, that's exactly the kind of problem we work on at South Shore Analytics. Feel free to reach out.
Thanks for reading!
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