I shook my head and nearly turned the coaches film off. I was exasperated at them being abysmal; them being the Bills defense. I thought about blaming defensive coordinator Dave Wannstedt for the dismal performance, but that was too easy. I thought about blaming multimillionaire Mario Williams and his wrist, but that was too easy too. Then I thought, well, they’re all doing their job wrong.

On a per game basis, the Buffalo Bills are ranked 31st in points allowed, 31st in yards allowed, 32nd in run defense, and 20th in pass defense, and the awfulness of the pass defense has arguably been caused by the supreme crappiness of the run defense. There isn’t really one area that one can point to and say “THAT’S what’s wrong”. The defensive line isn’t pursuing like they should from the backside at times, the linebackers can’t get off blocks and they’re hitting the wrong gaps at other times, and the defensive backs? They’re either not coming down in run support, or they’re confused as to what their responsibilities are. All of this and more happened against the Tennessee Titans this past Sunday, when the Bills gave up 7.3 yards per carry en route to 197 yards overall on the ground.

Here’s 16 of them: it’s 2nd down and with nine yards to go in the first quarter for the Titans, who are in 21 — two backs and one tight end who is right (strong-side) of the formation — personnel. The Bills have three down linemen and a weak-side rusher standing up to create a 3-4 Over look. The Titans play call would be a  lead to the back-side of the formation, which meant that the Bills defensive line and linebackers would slide over and fill their gaps. Because of the strong-side linebacker sliding to his right to account for running back Chris Johnson, the strong safety had to come down and fill the alley.

He didn’t do that.

Once Johnson saw that their was a natural alley forming on the back-side, he sought and found it. Once he found it, he was (supposed to be) met by safety George Wilson, who was hesitant to come down and fill the alley, instead opting to sink his feet into the grass and watch Johnson make his first move. That move was to the outside, and by the time Wilson reacted he was too far away and too slow to run down the Titans ball carrier, who dove into the end zone for six points.

Run defense is not George Wilson's strong suit.

This was simply one play of many, not including the  ”three, really big explosive plays” according to linebacker Nick Barnett that the Titans had running the ball. The veteran linebacker elaborated on the Bills run defense and its struggles in a post-game interview:

Well, we had mistakes. We went in wrong holes, did not box, did not hammer when we were supposed to be inside, just different things. I think he had three really big, explosive plays. And that is what it equated to. We have to clean those mistakes up. Against a back like that you cannot make any mistakes. If you give him any ground he is going to take off running. So we have to clean that up.

And he’s right, but it doesn’t stop there. Although the pass defense wasn’t as awful on paper –holding the Titans to 6.2 YPA (yards per attempt) — they couldn’t defend the second and long passes of the Titans, and they couldn’t get off the field on third down. The Titans went 7 for 12 on third down in the game.

With 14 minutes left in the fourth quarter, Tennessee motioned to a stacked Twins (two receivers) set to the wide side (“field”) of the field from a shotgun set. Because of the motion, the Bills made a check in their defense and appeared to go to the popular Man-Under (Cover 2 Man) coverage. This consisted of two deep, split-field safeties, and man coverage underneath from the defensive backs and linebackers. In this coverage, the defensive backs either line up or shift post-snap to an inside shade of the pass catcher, which allows them to be more aggressive in attacking inside breaking routes because of safety help over the top.

What went wrong for Buffalo on this coverage concept was that not everyone was playing Man-Under; everyone but rookie cornerback Stephon Gilmore to be specific. This was a problem because the Titans were going to be flooding Gilmore’s area of the field, which ended up having one receiver running wide open underneath for a catch and first down, and he (appeared) to be responsible for the uncovered stacked (second) receiver.

To Man-Under or not?

Oh, there’s more. On 2nd and 18 with 2:44 to go in the fourth quarter, the Bills were in Man-Under once again and everyone– except slot corner Justin Rogers — had their assignments against the Titans’ Doubles (2×2 set) formation. Rogers, who was lined up in the slot against receiver Nate Washington, initially appeared to play the receiver correctly; he had an inside shade and was aggressive in defending the inside-breaking route. However, as Washington broke off his route, Rogers became too aggressive and ended up taking too wide of a path to the receiver, consequently allowing significant real estate for yards after the catch.

And that’s exactly what happened as the Titans picked up yet another drive-extending first down after an 18-yard gain.

Not again.

Mistakes like these have made the Buffalo Bills defense struggle immensely, which has been truly unfortunate as it features some physically talented players.

Most will say that Wannstedt takes the majority of blame for this disastrous defense, but that might be unfair as the defense is simply not executing their assignments regardless of what kind of scheme is being used. They are struggling with the fundamentals of football, and as Barnett noted, until they start executing those basic plays, criticizing Wannstedt’s defensive design is difficult.