For all the praise Brady gets, he's more of a system QB than, for instance, Peyton Manning or Rodgers or Brees. That's why certain defenses with the right personnel have had consistent success against him.
Despite his mistakes, Allen is playing with the efficiency that it takes to keep up with the Pats. Having this defense certainly makes it easier.
The Bills have as good a shot as they've ever had. I think we see an upset on Sunday.