History & Timeline
2019
Independent Ball. ABS debuted in the Atlantic League as a full robot umpire using TrackMan technology. Human umpires wore earpieces and relayed automated calls in real time.
2021–23
Minor League Testing. The system expanded through Low-A, the Arizona Fall League, and Triple-A. MLB found that a 3D hovering pentagon created unnatural calls on breaking balls. Two formats competed: full ABS and a Challenge System.
2024
Challenge Wins. By the end of the Triple-A season, MLB fully committed to the Challenge System format. Players strongly preferred it — umpire judgment stays for borderline reads, challenges handle disputes.
2025
Final Approval. A full ABS Challenge experiment ran during Spring Training and the All-Star Game. The Joint Competition Committee voted in September 2025 to implement the system league-wide for 2026.
2026
MLB Live. Active in every Major League ballpark for the regular season. Each team gets 3 challenges per game. A successful challenge preserves it. Unsuccessful: it's gone.
Stadium Hardware
0.16"
Median Error Margin
5G
T-Mobile Private Network
Seven cameras track players and umpires. Five lock exclusively on the strike zone and baseball. The entire backend runs on a dedicated private 5G network — no shared bandwidth, no latency.
Measuring the Player
The 10 a.m. to Noon Rule. Every player is measured in this two-hour window on a rolling basis during Spring Training, by an independent party. Morning standardization eliminates spinal compression that accumulates throughout the day.
Stance doesn't matter. Players stand completely straight — no shoes, no hat. A crouched batting stance no longer shrinks the zone. As a result, 225 of 430 Opening Day hitters in 2026 measured at least an inch shorter than their traditional roster heights.