This list is omitting some of the greatest players of all time. Marino, Elway, Namath, Earl Campbell, Bradshaw won 4 Superbowls. Mean Joe Green and the list goes on.....
Interesting quiz, though impossible to select a 20 best. Leave in Manning or Elway, leave in Sanders take out Smith and Jim Thorpe, and so on. Single best cornerback, tight end, center and offensive guard of all time, whoever they are, don't make the list.