Computerized strike zones could be coming to MLB within the next five years, the Associated Press reports. Here are the nuts and bolts, per the report:
Umpires agreed to cooperate with Major League Baseball in the development and testing of an automated ball-strike system as part of a five-year labor contract announced Saturday, two people familiar with the deal told The Associated Press. The Major League Baseball Umpires Association also agreed to cooperate and assist if Commissioner Rob Manfred decides to utilize the system at the major league level.
They've been testing mechanisms for this in the independent Atlantic League and the Arizona Fall League. Single-A is next for the upcoming season, and then Triple-A in 2021. It sounds like this is going to be the standard for all calls as opposed to just available for challenges, and that they'll still need human umpires for checked swings and out/safe (and also to make sure the robot umps don't malfunction and call strikes on bounced balls).
The system is called TrackMan, and it works using Doppler radar and then communicating the call via a cellphone held by the home plate umpire.
Aside from the issues that baseball traditionalists are invariably going to have with this system when it inevitably gets implemented, the testing so far has not exactly gone swimmingly. Via Baseball America:
Hitters throughout the brief AFL season were getting rung up on pitches catchers were scooping out of the dirt as well as ones that crossed somewhere near the middle of a hitter’s chest. By the end, two things were clear: Pitchers with arsenals geared toward working from the top to the bottom of the strike zone were at a stark advantage, and nobody—neither hitters nor pitchers—was happy with TrackMan.
So it's likely that all of us who watch a lot of baseball are still going to get annoyed at the robot umpires just like we have at the people calling balls and strikes. The ejection outbursts are sure to still happen and be entertaining.