An ambidextrous, all-state high school football and baseball player from California, Smith had a tryout with Houston at Dodger Stadium his senior year, but signed with Minnesota as a shortstop in 1963. Left unprotected by the Twins after his first pro season, the strong-armed switch-hitter was drafted by the Red Sox, who made him an outfielder. As a rookie, he helped Boston to the 1967 pennant and homered twice in the World Series. A fixture from 1967 through 1973 in potent Fenway outfields, first in center, later in right, he batted .300 three times and won a Gold Glove in 1968 when he led AL outfielders in putouts. In 1968 and 1971, he topped the league in doubles.
Traded to St. Louis with Ken Tatum for Rick Wise and Bernie Carbo in October 1973, Smith had two All-Star seasons for the Cardinals in 1974 and 1975. He hit three HR in a May 22, 1976 game before moving on to the Dodgers in June. On the way to the 1977 NL pennant, Smith, Steve Garvey, Dusty Baker, and Ron Cey became the first four teammates in baseball history to each hit 30 or more HR; Smith hit a career-high 32. He was a major factor in the Dodgers’ 1978 league title, hitting a club-high 29 HR, and adding three HR in the WS loss to New York.
Shoulder, neck, knee, and ankle injuries plagued Smith in his final four ML seasons. He batted .284 as a Giants first baseman in 1982 before signing to play in Japan. He retired second to Mickey Mantle in HR by a switch-hitter; as the only switch-hitter with 100 HR in each the AL and NL; and as the only player to homer from both sides of the plate in a game twice in each league. Only Smith and Frank Robinson appeared in WS and All-Star Games for both leagues.