https://www.nytimes.com/athletic/7163482/2026/04/01/mlb-umpires-abs-system/
What is a strike?
The answer to that question has traditionally been easy for MLB umpires: A strike is whatever I say it is.
However, amid the introduction of the automated ball-strike challenge system, highly experienced former MLB umps are critical of baseball’s newest technology.
Citing their own observations and conversations with those currently still in the job, the consistent criticism has been simple: What’s a ball and what’s a strike has changed, and they don’t know how, exactly, to call it.
“The strike zone has never been an exact science,” said longtime former umpire Gary Darling. “They’re flipping pitches that are missing by a tenth of an inch, in a system that’s not exact anyway. … As much as baseball wants to define the strike zone, it’s still not defined.