Automated Ball-Strike System on Conor McLaughlin

Baseball's Great Height Correction

Thu, 09 Apr 2026 22:47:29 -0700

For the 2026 season, Major League Baseball introduced its challenge system to great fanfare, with the Automated Balls/Strikes (ABS) system serving as a backstop to overturn (or validate) calls made by the umpires.

In doing so, MLB finally formalized the definition of the strike zone - no longer would it be “knees to letters” at the discretion of umpires - now it ranges from 27% to 53.5% of the batter’s measured height.

Checking in on Triple-A's Robo Umpires

Sat, 20 Jul 2024 22:58:24 -0700

Major League Baseball (MLB) has a long history of using the minors as a sandbox for rules reforms - with the recent testing and rollout of the pitch clock as a prime example.

This season, the “robo ump”, formally known as the automatic ball-strike (ABS) system, is being trialed across all of Triple-A. This system implements the strike zone as a rectangle set in the middle of the plate, measuring 17 inches wide and spanning between 27% and 53.5% of the batter’s height.