What is the proposed ball-strike challenge system in MLB? - AS USA

Column: Improving ball-strike calls is a challenge MLB needs to take on, Professional: All Sports

What is a strike in baseball? Robots, rule book and umpires view it differently

Triple-A's Ball/Strike Pitch Location Challenge System Update and a Minor League Ejection in OKC

Triple-A parks to use new electronic strike zone

Automated Ball Strike System: Sugar Land Space Cowboys now able to challenge robot umpire calls at Constellation Field - ABC13 Houston

Arizona Fall League Testing Automated Ball/Strike System, Bugs and All

Robot umps, challenge system, or neither? WooSox players weigh in

Humans are out! Hawk-eye robo ump, a new strike-calling system, will debut this week at Harbor Park. – The Virginian-Pilot

The automated strike zone is moving on up to Triple-A in 2022 - Bleed Cubbie Blue

Columbus Clippers to use automated strike zone in 2023 Triple-A season

The Nashville Sounds help test out robotic umpires. Is this the future?

Ball-Strike Challenges Among Experimental Rule Changes In Minors In 2022 — College Baseball, MLB Draft, Prospects - Baseball America

Electronic Strike Zones to Be Used by All 30 Triple A Teams, per Report - Sports Illustrated