Miller had the perfect motion and brilliant mastery of the changeup, which made him perfectly suited as a relief pitcher who faced batters only once or twice in a game. They opposing batters couldn’t adjust because they were guessing wrong most of the time.
“Miller’s changeup was so good because his motion was so hard to figure out,” Mudcat Grant said.
Originally a starting pitcher, Miller didn’t throw very hard and had troubles early in his career. In his first five seasons, mostly as a starter, he had a 4.27 ERA and bounced around to three different teams. Finally, with the Giants in the late 1950s, Miller learned to master his changeup, using a fastball-like motion on a pitch that went to home plate at speeds no higher than 84-84 MPH. Under Billy Rigney after the Giants moved to San Francisco, Miller was utilized as a relief ace, entering games in the 7th, 8th, or 9th innings to hold a lead or keep the game close. He twice led the league in saves in the 1960s, doing it once in each league.
“He had three speeds for his pitches: slow, slower, and slowest.” - Milt Pappas
“….I still don’t see how Stu Miller threw the ball that soft and got it to home plate.” - Frank Robinson