We're aren't big fans of the genre, but if forced, we would name the standard-bearer as Sports Illustrated's 1985 prank, The Curious Case Of Sidd Finch.
According to the article by George Plimpton, the New York Mets had acquired a pitcher/Harvard dropout/recluse/yogi who was "a 28-year-old, somewhat eccentric mystic named Hayden (Sidd) Finch. He may well change the course of baseball history. On St. Patrick's Day, to make sure they were not all victims of a crazy hallucination, the Mets brought in a radar gun to measure the speed of Finch's fastball. The model used was a JUGS Supergun II. ... The highest number that the JUGS had ever turned for a baseball was 103 mph, which it did, curiously, twice on one day, July 11, at the 1978 All-Star game when both Goose Gossage and Nolan Ryan threw the ball at that speed. On March 17, the gun was handled by Stottlemyre. He heard the pop of the ball in Reynolds's mitt and the little squeak of pain from the catcher. Then the astonishing figure 168 appeared on the glass plate."
It's a classic tale.