This article is a summary of a YouTube video "MLB's Slowest Pitcher Was Completely Unhittable" by Look, It's Baseball

The Unhittable Rookie Pitcher of 1986: Mark Icorn

TLDRMark Icorn, a rookie pitcher in 1986, revolutionized the game with his unique submarine delivery. Despite throwing pitches as slow as 70 miles per hour, he became one of the most dominant relievers of all time. With a remarkable ERA and strikeouts, Icorn baffled hitters and left a lasting impact on the game.