He played his college football at UCLA where he was the last single-wing tailback, a position that required a player to pass, run, and kick. In 1960, his final season, he threw for over 1,000 yards, ran for over 800, scored eight touchdowns, was the team's punter, and finished fifth in voting for the Heisman Trophy, leading the nation with 1,889 yards of total offense and becoming an All-American. He was also named Most Valuable Player in the 1961 College All-Star Game and received the1960 W.J. Voit Memorial Trophy as the outstanding football player on the Pacific Coast.
He was picked in the first round of the 1961 NFL draft, eleventh overall, by the San Francisco 49ers where he was utilized primarily as a running back. During his rookie year he rushed for 509 yards and ten touchdowns, four coming in one game against the expansion Minnesota Vikings.
A ball control quarterback, he remained the primary starter from 1971-’77, going 49-22-1 in that time. He credits his passing improvements to Jurgensen, who he said helped him with his grip and his throwing mechanics, mostly his hip rotation.