Culp signed with Philadelphia for $100,000 in 1959. As TSN NL Rookie Pitcher of the Year four years later, he led the Phillies with 14 victories and posted a second 14-victory season in 1965. Often plagued by arm troubles, he slumped in 1966 and was traded to the Cubs. Dealt to Boston after one mediocre season, in 1968 he began using a palm ball and went 16-6, which included four straight shutouts. He won 17 games each of the next two seasons. On May 11, 1970, he struck out the first six batters he faced, tying the AL record.