Ramsey, after college, played ball in the NFL for the Chicago Cardinals. He served as a player/coach there and then left to become the Detroit Lions defensive coordinator in 1952. During his tenure with the Lions, Ramsey developed the 4-3 defense, a staple of modern football. In addition, he was the first coach to blitz linebackers in a package he called Red Dog. and later was hired by Ralph Wilson as the first Head Coach of the AFL/NFL Buffalo Bills franchise.