Umpires first began calling both balls and strikes way back in 1864, and baseballers have been arguing about those calls ever since. Strike-zone judgment has been the subject of some untold number of verbal (and,

Here's a first look at MLB's Automated Ball-Strike challenge system, a compromise between full robot umpires and human umpires, in action during spring training.

A computerized system that calls balls and strikes is being tested during MLB spring training exhibition games starting Thursday.