The Bills showed a blitz in the front and quarters defense, or four deep, in the back end.

The Bills backed out of the blitz (right) and revealed their deep quarters defense. The key is Julian Edelman sitting down on a hitch route.

The safety sat on Edelman, leaving Rob Gronkowski 1-on-1 with Nickell Robey-Coleman.

And when Gronk caught the perfect pass (right) it was off to the races for his franchise-record TD.

Danny Amendola received five great blocks on this kickoff return to open the second half . . .

Plus three more great blocks . . .

Plus another great block to help spring him for 73 yards.

And Amendola returned the favor two plays later, laying a perfect cut block to help Edelman get around the corner for a 12-yard touchdown.