Blue Notes · Umpire Grade2026-04-29
KC @ ATH
Home plate: John Libka
“An honest evening's grade: nothing loud, nothing missed by much.”
Umpire Grade
94.8% accurate
Run Favor
runs, ATH
ABS Overturns
of 1 reviewed
What this shows — how John Libka called the 154 pitches that were taken (no swing), graded against the tracked rulebook strike zone. He got 146 right. Below, only his misses are plotted, alongside every pitch the ABS (Automated Ball-Strike System) reviewed on a challenge.
The zone, as he called it
strike called ballball called strikeABS overturnedABS upheld
The calls that moved the game
- 1+0.30▼1 · 3-1 strike called ball
Carlos Cortes vs Michael Wacha - 2+0.23▼1 · 0-2 strike called ball
Nick Kurtz vs Michael Wacha - 3+0.23▲8 · 0-2 strike called ball
Lane Thomas vs Joel Kuhnel
Run impact from the count run-value table: a missed strike three is worth far more than one on 3-0.
ABS — the Automated Ball-Strike System
1 pitch went to the robots · 0 overturned (ump overruled) · 1 upheld (ump confirmed). This is Hawkeye ground truth, no model involved.
- 1Shea Langeliers — ump said ball, robot ruled ball: upheld.
Our tracked-rulebook zone matched the ABS ruling on 0 of 1 — a zone-definition gap (ABS grades a standardized, height-based zone), not our error.