He earned a save in the 1935 game, pitching three scoreless innings to finish a 4–1 victory, and another in with three shutout innings in the 8–3 win; he also finished the 4–3 loss played at Cleveland in with two innings. In 1940, he posted a 12–11 record, as the Indians finished one game behind the pennant-winning Detroit Tigers, wasting an early September lead amid clubhouse rancor; it would be the only season in his career in which the Indians came within ten games of the AL flag. After several more years in which his record hovered near .500, earning his 200th victory in , Harder ended his career in with 1160 strikeouts and a 3.80 ERA. In addition to his 223 victories, his 186 losses remain a club record. Ironically, the Indians won the World Series the year after he retired. From 1948 into the 1950s, he guided what became known as the Indians' "Big Four" pitching rotation, featuring Feller, Bob Lemon, Early Wynn and Mike Garcia; Harder had successfully transformed Lemon from an infielder into a top pitcher while working with him in the mid-1940s, and he taught future 300 game-winner Wynn the breaking ball and changeup. Wynn had had a losing record (72-87) before being traded to the Indians by the Washington Senators. In 1953, Lemon tied Harder's record by leading AL pitchers in putouts for the fourth time, and he broke the record the following year as the Indians won another pennant, but lost to the underdog New York Giants in the World Series. Herb Score was named the AL's Rookie of the Year in after Harder helped to develop his curveball. During his coaching career, Harder served as interim manager of the Indians for the last game of the season and the last two games of , winning all three contests. Late in his tenure, prominent young pitchers as Sam McDowell, Tommy John and Luis Tiant would come under his guidance. He was fired after the 1963 season, having spent the first 36 years of his adult life in Cleveland. He later coached with the New York Mets (1964), Chicago Cubs (1965), Cincinnati Reds (1966–68) and Kansas City Royals (1969). Cleveland retired his pitching uniform number 18 on July 28, 1990 (he wore 43 and 2 as a coach), and he was named one of the Indians' top 100 players in 2001. In 2002, Harder died in Chardon, Ohio at age 93; at the time of his death, he had been one of only five living players who had played in the 1920s.