Robot umpires and a ball/strike challenge system are coming to Triple-A in 2023 - Bleed Cubbie Blue
Triple-A's Ball/Strike Pitch Location Challenge System Update and a Minor League Ejection in OKC
MLB just tweaked Triple A's electronic strike zone: What you need to know and why it matters - The Athletic
We are getting closer to an automated ball-strike system in MLB - Bleed Cubbie Blue
Smith: Automated ball-strike system is here to help
MLB's runner-on-second in extras rule reportedly could return; league testing ball-strike challenge in minors
What is the proposed ball-strike challenge system in MLB? - AS USA
Automated ball-strike (ABS) system, pitch timer, bigger bases tested at Triple-A
MLB Umpires Missed 34,294 Pitch Calls in 2018. Time for Robo-umps?, BU Today
Sources - All AAA parks to use electronic strike zone in '23 - ESPN