For a five-year stretch in the mid-1960s, Joe Horlen had the lowest ERA in the American League and was one of the best pitchers in baseball. He was the ace of one of the better pitching rotations of that era, topping a White Sox quartet that also included Tommy John, Gary Peters, and Juan Pizarro.
Horlen was a pitch-to-contact pitcher who got away with it because his fastball had natural movement and his hard fastball was very effective. In 1967 he led the AL in ERA and shutouts and won 19 games, finishing second in Cy Young voting. That season he didn’t lose until June 23rd and he helped the White Sox stay in the pennant race until the final weekend of the season.
The righthander was hounded throughout his career by criticism that he wasn’t rugged enough: he did not complete as many games as other top pitchers in the game. Still, he averaged 32 starts and 224 innings per season from 1964-1968, when his 2.32 ERA was tops in the league.
In spite of his protestations that his arm was strong, Horlen succumbed to arm injuries in his early 30s, and was eventually relegated to the bullpen. In 1972 he performed well in a relief role for Dick Williams as the Oakland A’s won the World Series. He was released in the off-season and retired at the age of 34.