Ruthven had little success as a temperamental young starter with the Phillies in 1973-75, and led the National League with 17 losses for the Braves in 1976. A dispute with Braves owner Ted Turner sent him back to Philadelphia in mid-1978 and he went 13-5 with a 2.98 ERA for the Phillies that year to help them win the NL East. He was 6-0 in 1979 before an injury curtailed his effectiveness. Ruthven rebounded in 1980 to go 17-10 as Philadelphia reached the World Series, and he won the deciding game of the NLCS in relief, pitching the final two innings of a 10-inning, 8-7 win over Houston. After a 6-1 start earned him spot on the 1981 NL All-Star team, his ERA ballooned to 5.14 and he finished the season 12-7. He was traded to the Cubs in 1983 and was 10-17 in his final three seasons with Chicago.