MLB Umpires Performing Well in ABS Era So Far

Data shows high accuracy rates and increasing transparency in new automated ball-strike system

Apr. 17, 2026 at 4:20pm

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A fractured, multi-perspective painting in a cubist style, breaking down a baseball game or umpire's strike zone calls into sharp, overlapping geometric planes in vibrant colors.The new Automated Ball-Strike System is bringing unprecedented accuracy and transparency to MLB umpiring, deconstructing the strike zone into a cubist masterpiece.Atlanta Today

Major League Baseball implemented a new Automated Ball-Strike System (ABS) this season, giving each team two challenges per game on home plate umpire calls. The data so far shows umpires are performing well, with only about 1% of pitches being challenged and 54% of those challenges resulting in overturned calls. Fielding teams are having more success with challenges than batting teams, and the majority of umpires are missing calls by less than an inch on average.

Why it matters

The new ABS system aims to bring more transparency, reliability, and accuracy to MLB's strike zone calls, which have long been a source of frustration for players, managers, and fans. These early results indicate the system is working as intended and helping to improve umpire performance.

The details

Through the first three weeks of the season, there have been 1,143 challenges on ball/strike calls, which is about 4 per game. This constitutes only around 1% of the roughly 80,000 pitches thrown. Of those challenged calls, 54% have been overturned. Fielding teams are having more success with challenges at 60% compared to 47% for batting teams. The Atlanta Braves have been the least successful when batting, while the Washington Nationals have been the least successful when fielding. Importantly, 49 of 83 umpires are missing calls by less than an inch on average, and umpires can now get real-time feedback from the ABS operator on any pitch, which should continually improve their accuracy.

  • The new Automated Ball-Strike System (ABS) was implemented at the start of the 2026 MLB season.

The players

Angel Hernandez

A veteran MLB umpire known for making controversial and inaccurate calls behind home plate.

Savant

A comprehensive tool for MLB advanced analytics that hosts, analyzes, and visualizes Statcast data.

Kendall Baker

A sports reporter for Yahoo Sports who provided additional context on the new ABS system.

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What they’re saying

“umpires, outfitted with earpieces, can now get real-time feedback on any pitch (challenged or not) by asking the ABS operator, "Did I miss that?" Those data points should add up to continually improve their accuracy moving forward.”

— Kendall Baker, sports reporter

What’s next

As the season progresses, MLB and fans will continue to monitor the performance of umpires under the new ABS system. The league will likely use the real-time feedback and data to further refine the system and improve accuracy.

The takeaway

The early results of the new Automated Ball-Strike System in MLB show that umpires are performing well, with a high percentage of calls being accurate and a low percentage of challenged plays. This suggests the system is achieving its goals of bringing more transparency, reliability, and accuracy to the strike zone, which should build trust among players, managers, and fans.