In American football, the A formation was a variation of the single-wing formation used with great success by the New York Giants of the 1930s and early 1940s. This formation was masterminded by Giants coach Steve Owen and relied heavily upon Hall of Fame center Mel Hein for its success. A great center like Hein was a major asset, albeit not essential, in running the A formation — however only the Giants used this set-up with any frequency. This gave the Giants an advantage in that teams had to prepare specifically to defend the A whenever they played New York.