As far back as 1939, futurists envisioned replacing the baseball umpire with a machine!

In the summer of 1939, Popular Science peered into the fantastical future of athleticswith a story headlined “New Inventions in the Field of Sports.” In between the “merry-go-round training machine” for rowers, and a proposal for polo on horses in water — a “thrilling new aquatic sport” — there was a futurist gem: the Electrical Umpire.

A quarter-page illustration detailed the intricate system of light beams comprising the guts of the (entirely fictional) machine. “Electric eyes” several feet to the left and right of each batter would determine whether the ball passed through the strike zone, defined as the area from the upper chest down to the knees. A projector strung along a clothesline 10 feet overhead would shoot light straight down at a mirror under home plate and recognize if the ball passed over the plate, if it had broken the vertical beam of light. When a pitch satisfied those two criteria — in the strike zone and over the plate — an indicator light signaled a strike.

Now, if only John Roberts could be digitized.