(born 1953), Hispanic American baseball player. Fine first baseman Keith Hernandez was born on Oct. 20, 1953, in San Francisco, Calif. He studied at the College of San Mateo and played first base for the St. Louis Cardinals from 1974 to 1983, for the New York Mets from 1983 to 1989, and for the Cleveland Indians from 1990 to 1991. He played in three championships and two World Series—in 1982 with St. Louis and in 1986 with the Mets. Hernandez, who batted and threw left-handed, was on the National League All-Star Team in 1979, 1980, 1984, 1986, and 1987. He led the league in double plays in 1977, 1979, 1980, 1981, 1983, and 1984. In 1992 he appeared as a guest star on the television series Seinfeld.