John Clayton: NFL: Where do the Indianapolis Colts' Peyton Manning and the Minnesota Vikings' Brett Favre rank among history's greatest QBs? Favre or Manning could improve his ranking on Clayton's list of the 10 best-ever QBs. In: sports.espn.go.com. ESPN, 19. Januar 2010, abgerufen am 29. Dezember 2013 (englisch, One of the problems of comparing eras is how the game changes. Until the 1980s, the NFL was a running league. That's why Graham and Unitas can't be forgotten. They set standards of excellence for passers that opened the door for the Montanas, Elways and Mannings to thrive.): „Unitas opened the eyes of coaches who loved running the football and playing defense. He taught the NFL that a smart quarterback could lead a passing attack from the field and become the ultimate field general.“
