quarterback (n.)

in U.S. football, 1876, from quarter (n.) + back (n.); so called from his position on the field at the start of play, between the halfback and the center. As a verb from 1945. Figurative sense from 1952. Monday morning quarterback is 1932 (n.), 1972 (v.); originally pro football player slang for sportswriters (U.S. professional football games typically are played on Sundays).