The Best (and Worst) ABS Challenges From MLB’s Opening Week

ABS is here, and it is glorious.

MLB’s new challenge system for balls and strikes has been active for just a few days, and it has immediately and fundamentally altered baseball’s strategy. Players have always thought an umpire’s borderline ball or strike call was bogus; now, they not only have the ability to do something about it (besides lose their minds), but they must calculate in a matter of seconds whether or not it’s worth it to do something about it right now.

Since teams can only have two unsuccessful challenges before they’re done for the game, picking the right spots to challenge a ball or strike call is as important as being right about the call itself. And it hasn’t taken long for there to be plenty of standout examples on both sides of the spectrum.

With a new age in umpire grievances freshly underway, here are the best and worst ABS challenges of the young season. While these extremes will surely be topped as we go along, they stand now as foundational benchmarks to perhaps help teach players what to do (and, crucially, what not to do) when a call doesn’t go their way.

ABS challenge data comes from Tap to Challenge.

Best: Ryan Helsley tips his cap (on time)

It’s only right that this successful challenge—which resulted in the opposing manager getting ejected—earns a spot in the “best of” section. With the Orioles leading the Twins, 8–6, with one out and a runner on first in the top of the ninth, Helsley faced Josh Bell with a full count. His next pitch caught the inside of the plate but was initially called a ball. Helsley tapped his cap to signal a challenge, and the call was overturned.

Twins manager Derek Shelton was LIVID as he argued that Ryan Helsley didn't challenge this call fast enough pic.twitter.com/NnsgUb3iap
— Jomboy Media (@JomboyMedia) March 29, 2026

But, apparently, Twins manager Derek Shelton was not pleased with how long it took Helsley to decide to challenge, even though the pitcher touched his cap within a second of the ball call. Shelton’s protests fell on deaf ears and he was eventually tossed. With two outs, the next batter reached on an error, but Helsley retired James Outman to seal the win.

Per Tap to Challenge, Helsley’s challenge was worth 13.3% Win Probability Added, making it easily the most positively impactful challenge of the young season.

Worst: Matt Wallner gets caught looking

We stay in the same game (and not for the last time) for this one. With the bases loaded and two outs in the seventh inning of a tie game, Wallner faced Baltimore’s Rico Garcia with a full count. He took a pitch that was immediately called for strike three, and the replay shows why home plate umpire Chris Segal had no hesitation making the call.

Matt Wallner took this pitch with the bases loaded and two outs then challenged the strike call. pic.twitter.com/s8kkNd8X9i
— Codify (@CodifyBaseball) March 29, 2026

Wallner’s challenge was not only unsuccessful, but it was Minnesota’s last remaining challenge for the game. At 4.77 inches from the edge of the strike zone, this is the furthest distance for any pitch that’s been challenged so far this year.

Best: Eugenio Suárez goes back-to-back

Facing the Red Sox in the bottom of the sixth inning with the bases loaded and two outs, Suárez twice got called out on strikes by home plate umpire C.B. Bucknor on back-to-back pitches—and twice successfully challenged. The resulting roar from the crowd was a new kind of momentum swing that added a fun layer to the proceedings.

C.B. Bucknor tried to ring up Eugenio Suárez on back-to-back pitches.

Suárez challenged both and won both challenges.

(H/T: @tylermilliken_) pic.twitter.com/erzchAXPw0
— Foul Territory (@FoulTerritoryTV) March 28, 2026

Suárez eventually grounded out to end the inning, but the way the crowd got involved in this sequence showed that replays can be fun for everyone involved (except, in this instance, for Bucknor).

Worst: Logan O’Hoppe freezes up

The early days of ABS have taught us that sometimes, it’s not whether or not a call gets overturned or upheld, but whether or not a player decides to challenge at all that ends up swinging games. With runners on the corners in the bottom of the eighth inning of a tie game and two outs, Angels pitcher Drew Pomeranz seemed to catch the strike zone on a 2–2 pitch to Isaac Paredes. The pitch was called a ball, and though Los Angeles had a challenge remaining, neither Pomeranz nor catcher Logan O’Hoppe opted to challenge the call.

This was the 2-2 pitch, called a ball, just before Isaac Paredes got a go-ahead 2-run double.

Could have been strike three to end the inning

The Angels are now down 9-6. pic.twitter.com/K0JVGEA7IV
— Jeff Fletcher (@JeffFletcherOCR) March 29, 2026

Paredes doubled in two runs on the next pitch, and the Astros won 9–7. By not challenging the call, O’Hoppe and the Angels left 10.5% WPA on the table, per Tap to Challenge, representing the biggest missed opportunity of the season so far.

Best: Kirk gets Kurtz

This challenge was all about timing. With the Blue Jays leading 2–1 in the top of the ninth, it was imperative for Toronto to retire leadoff hitter Nick Kurtz. With a 2–2 count, Kurtz took a pitch that just nipped the outside edge of the strike zone, and Kirk immediately challenged. With a net WPA of 9.3%, this stands as the second-most impactful challenge we’ve seen yet.

Athletics first baseman Nick Kurtz — A’s first baseman Nick Kurtz missed a chance to give his team much better odds of beating the Blue Jays on Friday. | Jordan Godfree-Imagn Images

Worst: Nasim Nuñez misses his chance

Nuñez batted against the Cubs in the top of the sixth inning with the bases loaded, nobody out and his team leading, 3–2. Clearly, this was an ideal scoring situation for the Nationals, so it was curious that Nuñez opted to challenge (unsuccessfully) on a 1–1 pitch that was very much a strike.

Washington stood to gain very little on getting a 2–1 count over a 1–2 count from a WPA perspective in this situation, and the failed challenge left the team with none for the rest of the game. Nuñez struck out looking three pitches later, though the Nationals ended up adding on an insurance run in the inning and eventually won, 6–3.

Best: Samuel Basallo swings the odds

Back to Matt Wallner and the Orioles-Twins game from Sunday. Rico Garcia’s 1–1 pitch caught the bottom of the zone but was called a ball. Basallo wisely challenged and got the call overturned. Unlike the Nuñez scenario above, going from a 2–1 count to a 1–2 count actually did meaningfully alter Baltimore’s chances in this situation, as the score was tied 5–5 in the seventh inning with the bases loaded and two outs. Wallner struck out looking four pitches later, as detailed above, proving that the best and worst moments of baseball’s new reality can be just a few moments apart.

Worst: All of the first inning challenges

As always, adjustments to significant rule changes take time. But already, we’ve seen far too many examples of players challenging calls at moments in the game where they do not need to. Prior to Tuesday’s games, there were 19 instances of players challenging calls in the first inning, with 11 of them getting overturned. None of those successful challenges had a meaningful impact on the outcome of the game, and eight of them foolishly left their respective teams with just one challenge left for the next eight innings.

The worst of this group came from Braves outfielder Ronald Acuña Jr., who challenged the second pitch of Atlanta’s March 28 game against the Royals on a 1–0 count (he eventually flew out to right field). That failed challenge cost the Braves 1.3% WPA, the lowest mark of any challenge to date, signifying that the loss of the challenge was far more costly than the result of Acuña’s at-bat.

These are still the early days of a seismic change to the way baseball games operate, so the learning curve will understandably take time. But for now, players would be wise to save those challenges for later in the game—or, at the very least, until after the first inning.