PHOENIX — MLB's newest automated ball-strike (ABS) challenge system is leaving players, coaches and fans with a multitude of feelings this Spring Training, as the system is set to make its regular-season debut this year.
For Arizona Diamondbacks pitcher Ryan Thompson , it seems counterintuitive.
Arizona Diamondbacks pitcher Ryan Thompson (81) during spring training workouts on Feb. 10, 2026, at Salt River Fields in Scottsdale. © Rob Schumacher/The Republic / USA TODAY NETWORK via Imagn Images
The league's new system is part of its ever-evolving game and its effort to ensure games are called as fairly as possible. The system allows pitchers, catchers and batters to challenge certain pitch calls, with the opportunity to overturn a ruling if they believe a pitch was incorrectly called a ball or a strike.
However, during Spring Training, there have been noticeable pauses in play as challenges are reviewed to determine where a pitch crossed the plate. While some believe the delays are worth it to ensure fairness, others — including Thompson — question whether the system will ultimately work in the game's favor.
Just three seasons ago, MLB implemented the pitch clock and limits on mound visits to help accelerate games. Those measures reduced the average game time and improved pace and fan engagement.
Sep 26, 2025; San Diego, California, USA; Arizona Diamondbacks relief pitcher Ryan Thompson (81) throws a pitch during the eighth inning against the San Diego Padres at Petco Park. Mandatory Credit: David Frerker-Imagn Images
Now, the time required for challenges could sacrifice shorter games in exchange for more accurately called pitches. Borderline calls have changed the trajectory of games and shifted momentum in an instant, and the ABS aims to ensure those moments are decided correctly.
Yet extended reviews can also disrupt momentum and interrupt rhythm. Thompson's reaction highlights the potential challenges the rule could present during the regular season, especially from a pitcher's perspective.
Jun 3, 2025; Atlanta, Georgia, USA; Arizona Diamondbacks relief pitcher Ryan Thompson (81) throws a runner out at first against the Atlanta Braves in the ninth inning at Truist Park. Mandatory Credit: Brett Davis-Imagn Images
With Opening Day approaching, it will soon become clear whether brief interruptions are an acceptable trade-off in pursuit of accuracy — even when the margin is tenths of an inch.
