ESPN.com recently wrote up a “GOAT Index”, which ranks the greatest QB’s of all-time according to the input from current and former NFL head coaches and executives.
The panel included Pete Carroll, Tony Dungy, Mike Holmgren, Howard Mudd, Wade Phillips, Mike Reinfeldt, Ray Rhodes, Mike Shanahan, Al Saunders and Norv Turner. Mike Sadano cites in the article that the panel had 330 seasons of combined NFL experience with 20 Super Bowl rings.
It has become consensus among most NFL fans and personnel that Tom Brady is the greatest quarterback who ever lived, and he finished first on this list, but Tony Dungy ranked him sixth.