Top individual Phillies seasons ages 35 and over
Starting Pitcher: Jerry Koosman (1984, age 41)
Koosman had a long career of success in the Major Leagues, mostly with the New York Mets and Minnesota Twins prior to coming to the Phillies in 1984. In fact, he had two 20-win seasons, two All-Star appearances and over 200 wins before putting on a Phillies uniform.
Koosman started to drop off in the years before he became a Phillie. From 1980 to 1983, he had a 42-40 record, 4.16 ERA, 1.340 WHIP, and only 5.1 strikeouts per nine innings. In 1983 he had a 4.77 ERA and 1.70 strikeout-to-walk ratio splitting the season between the rotation and the bullpen.
Koosman found the “fountain of youth” in his first year with the Phillies at age 41. Koosman won 14 games, had a 3.25 ERA and logged 224 innings. His win total was his highest since 1980 and his ERA lowest since he posted a 2.69 ERA with the Mets in 1976.
Koosman returned next season with the Phillies but had only a fraction of the success. In 19 games, he won six and lost four with an ERA of 4.62, making his last career appearance on August 21 of that year. Koosman finished his two-year tenure in Philadelphia with a record of 20-19 and a 3.67 ERA.
In 19 Major League seasons, Koosman won at least ten in thirteen of them. He reached the 200 strikeout plateau once when he won 21 with a 2.69 ERA for the Mets in 1976. Overall Koosman retired with 222 wins, 33 shutouts, 2556 strikeouts, and a 3.36 ERA.