What Spring Training Taught Us About ABS

The strongest spring finding was not that challenges were overturned 52.9 percent of the time. It was that the challenge environment changed materially across game states.

Challenges in innings one through three were overturned 58.8 percent of the time. In innings four through six, that rate dropped to 52.8 percent. In the seventh inning or later, but not in close games, the overturn rate fell to 47.0 percent. In truly late-and-close spots, seventh inning or later with the score within one run, the overturn rate dropped again to 40.3 percent.

That gap is too large to ignore. It is also the place where the spring dataset starts to become analytically useful.

A lower overturn rate in late-and-close situations does not automatically mean clubs were making worse decisions. It may mean those decisions were being made in a harsher environment: tighter margins, fewer obvious misses, more incentive to challenge marginal calls, and a scarcer challenge resource. In other words, challenge quality may not be declining as much as challenge difficulty is rising.

That distinction matters if the goal is to understand what ABS may look like in the regular season. Teams do not play most consequential games under spring conditions, but spring did show that the challenge mix changes once leverage rises. That means we should be careful about treating overall overturn rate as the main measure of team ABS quality.

The Cardinals are the cleanest example of why timing deserves its own treatment. They finished with 61 challenges, a 65.6 percent overturn rate, and the highest late-and-close share among the 40-plus-challenge teams at 16.4 percent. That does not prove that St. Louis has solved the system. The sample is too small for that. But it does show a profile worth monitoring: above-average volume, strong conversion, and meaningful willingness to challenge in the part of the game where overturns are generally harder to find.

The Cubs offer a slightly different version of the same idea. Their 70 challenges came with the highest late-game share in the 40-plus group, but a lower late-and-close share than St. Louis. That suggests one of the better spring examples of a club whose timing profile may matter more than its raw total.

This is where the spring data requires careful handling.

The league-level sample is meaningful. Over 1,900 challenges across 451 games is enough to say that ABS was heavily used and that team behavior was not flat. But the moment analysis moves into team or umpire splits, the sample thins out fast, and the appropriate level of confidence thins out with it. Even within the 40-plus-challenge group, the range only runs from 40 to 101 challenges per club. That is enough to identify tendencies. It is not enough to declare which organizations are smartest about this, or which dugouts are already optimized.

The umpire picture deserves the same caution. Jen Pawol and Mitch Trzeciak each saw 47 challenged calls, Pete Talkington saw 40. The overturn range among umpires with at least 25 challenged calls ran from Charlie Welling at 64.7 percent down to Macon Hammond at 36.0 percent, a 28-point gap that is wide enough to notice, but not stable enough to convert into hard reputational claims about specific umpires. The right interpretation is narrower: ABS pressure was not evenly distributed, and some plate environments produced meaningfully different review outcomes than others.

That should matter to clubs, because ABS is not experienced in the abstract. It is experienced against particular catcher setups, hitter profiles, dugout habits, and umpire environments. Spring did not settle how those variables interact, but it did show they are already interacting. Clubs that treat the system as uniform across all those dimensions are probably modeling it wrong.

The most responsible spring conclusion is not that one team already gets ABS while another does not. It is that some clubs appear to have entered the system with genuinely different priors, and if those priors hold, they will produce different strategic bets as the season develops.

Some of those differences probably reflect organizational preparation. Some may reflect who is empowered to initiate a challenge in the dugout and under what conditions. Some reflect different tolerance for early-game deployment versus late-game conservation. And some will simply turn out to be spring noise that evaporates by mid-April.

But if the broad profiles are real, and that is the key conditional, the regular season may reveal clubs making distinctly different wagers. Whether to use ABS aggressively as a correction tool from the first inning or preserve it for the situations where it costs the most to be wrong. Whether a lower overall overturn rate can still be strategically valuable if it is concentrated in the highest-leverage spots. Whether some dugouts are entering games with a clearer mental model of what kinds of misses are worth contesting and what kinds are not.

That last one is the question that matters most going into Opening Day. Not who won the spring overturn rate, but whether the spring profiles were the first evidence of actual organizational philosophy, or just six weeks of experimentation without a conclusion.

The Yankees staying a high-volume club, the Twins and Angels remaining front-loaded, the Cardinals or Cubs continuing to weight late innings: if those patterns hold into May, spring starts to look less like noise and more like the first sketch of a real ABS identity. If they do not hold, then we will have learned something important about how hard it is to sustain a coherent challenge strategy across a 162-game season.

Spring did not solve the system. But it gave ABS its first visible shape, and that is more than enough to work with.