The 1973 Major League Baseball season was the first season of the designated hitter rule in the American League. American League umpires began wearing red blazers with blue pants, a change from the navy blue coats and gray pants worn from 1968 to 1972. The red blazers were worn through 1979. California Angels ace pitcher Nolan Ryan broke Sandy Koufax's 1965 strikeout record of 382 when he struck out 383 batters during the season. The Oakland Athletics won their second straight World Series championship in seven games over the New York Mets.