Why Isn't Major League Baseball Using Robot Umpires for All Ball and Strike Calls? [UPDATED]
[Ed. comment: This story has been updated with a recent decision from MLB]
"dalek" writes:
What do Don Denkinger and Jim Joyce have in common? If you're a baseball fan, you might recognize them as umpires who are known for famously missing a critical call late in a game on national TV. Before Major League Baseball (MLB) embraced video-assisted replay (VAR), which it resisted long after other sports like football had demonstrated that replaces could be used successfully, there was no way to reverse the missed calls. Even after MLB finally allowed VAR to be used, by far the most frequent call in a game still cannot be reviewed: whether a pitch is a ball or strike.
The technology to track the fight of a baseball and reliably determine balls and strikes has been in use for a couple of decades. Systems like QuesTec, PITCHf/x, and Statcast can accurately track the flight of a baseball and determine whether its trajectory crossed the strike zone when it reached home plate. Statcast not only determines each pitch's horizontal and vertical location when it crossed the plate, but a plethora of other data like the pitcher's release point in three dimensions, the velocity when the pitch left the pitcher's hand, it's spin axis and rate, the pitch's acceleration in three dimensions, and a classification of the pitch type. Despite the capability to accurately call balls and strikes automatically, MLB still relies solely on human umpires this call.
The horizontal location of the strike zone is identical for every pitch, requiring that some portion of the baseball pass above home plate. However, the vertical location is defined as being from the bottom of the hitter's kneecap to the midpoint between the top of the hitter's pants and the hitter's shoulders. This is affected by the hitter's height, body shape, and their batting stance. A hitter won't have exactly the same batting stance on any two pitches, so the actual strike zone varies slightly from pitch to pitch, even for the same hitter. This data is determined by Statcast while the pitch is in flight, and is recorded in the sz_bot (bottom of the strike zone in feet above ground) and sz_top (the top, with the same units) fields in Statcast data. The flight of the baseball is currently tracked by 12 Hawk-Eye cameras stationed throughout each stadium, five of which operate at 300 frames per second. The images from the different cameras can be used to pinpoint the location of the baseball within a few millimeters. The same type of camera is used for VAR in tennis matches to determine if a ball was out of bounds.
Read more of this story at SoylentNews.