Cooper won more games (202) than any other Pirate lefthander, at least 17 games a year from 1917 through 1924 with a career-high 24 in 1920 and a league-best 22 in 1921. The sinkerballer twice led the NL with 27 complete games, and led in two other seasons with 38 starts.
Cooper’s fielding skills were exceptional, particularly his knack for picking runners off third base — seven in 1924 alone. His partner, Pie Traynor, would dive toward the bag as Cooper whipped a sidearm throw to third. Walter Schmidt caught him for most of his career with Pittsburgh and they knew each other so well that the battery wasted little time on signals. Cooper got a reputation as a fast worker.
A .239 lifetime batter, Cooper hit four homers in 1922, and hit .346 in 104 at-bats in 1924.