The Detroit Lions can't stop the run. That's what you'd think if you looked at the numbers: The Lions have allowed 1,101 rushing yards on 210 carries. That's an average of 5.2 yards per carry and 137.8 yards per game. If a running back were to average 5.2 yards per carry and 137 yards per game for an entire season, they'd be a first-team All-Pro.
So how can the Lions have the sixth-best scoring defense in football? How can they lead the league in forced three-and-outs when the opponent seems to be moving the chains at will? How can they routinely cede long runs (no team has allowed more 40-plus yard gainers) yet hold all opponents to just three combined rushing touchdowns?
The secret to the Lions bend-but-don't-break rushing defense is that they don't stop the run with the front seven—they stop the run with the back seven.
The Lions use a defensive alignment sometimes referred to as a "wide-nine" front:
The rush defensive end (Kyle Vanden Bosch, No. 93) lines up in the 9-technique spot, outside the tight end. The nose tackle (Corey Williams, No. 99) lines up on the center's shoulder. This creates a sizable gap between the nose tackle and the end. Remember that.
On the other side, the over tackle (Ndamukong Suh, No. 90) lines up at the 3-technique spot, on the outside shoulder of the right guard. The left end (Cliff Avril, No. 90) lines up in the 7-technique, on what would be the inside shoulder of the tight end.
Run or pass, all the Lions linemen are trying to get upfield. On pass plays, the ends are trying to get upfield on the outside edge to sack the quarterback; on run plays, they're trying to get upfield to seal off outside runs and disrupt screens. On pass plays, the tackles are trying to collapse the pocket to prevent the quarterback's escape; on run plays, the tackles are trying to collapse the pocket to shrink running lanes.
Remember when I said there was a big gap between Corey Williams and Kyle Vanden Bosch? It's Williams' job, whether double- or single-teamed, to push upfield and get into that gap. If he fails, there's a wide running lane. If the offense attacks that gap with a fullback or a pulling guard, there's a wide running lane.
Let's see this in action:
Sharp eyes will note that the "nose" in this clip is Sammie Hill, and he's heavily shaded from his 1-tech spot over towards the left guard (perhaps anticipating the run). At the snap, Suh rushes straight upfield as he's supposed to, but the guard he's across from pulls to attack the gap between Hill and Vanden Bosch. The center seals Suh off from pursuing the runner from the backside of the play.
Hill gets double-teamed by the left guard and left tackle, and he not only doesn't get upfield but gets overwhelmed by the O-linemen. The tight end seals off Vanden Bosch, and voilà: a hole in the D-line wide enough to run a truck through.
To make matters worse, the Broncos have a pulling guard AND a fullback leading the charge through the enormous hole. Surely, tailback Willis McGahee is about to bust a long gainer, right?
Wrong. Louis Delmas, sensing a strong-side run from the get-go, has cheated up so far that he's in front of the linebackers, just two yards from the line of scrimmage—and right in front of the gap the Broncos will attack. When the hole opens, Delmas cuts the fullback low, flipping him clean over Delmas's back. Andre Levy engages the guard and stands him up, as the left tackle peels off of Hill to block Tulloch.
Here's where the magic happens: Delmas, after WWE-ing the fullback, forces McGahee to bounce out of the running lane. Sammie Hill, having overwhelmed the left guard, pursues McGahee to the sideline. Tulloch quickly slips the left tackle and joins Hill in the pursuit. Amari Spievey and Justin Durant close in, having run over from the far side of the field, and McGahee is brought down for no gain.
In that clip, everything worked as it's supposed to. The ends got upfield and funneled the run inside. The tackles couldn't collapse the running lane, but it didn't matter: the back seven all read the play, flew to the ball and stopped the runner as cold as if Hill had split the double-team and made the tackle himself.
Of course, it doesn't always work like this.
Often, the linebackers are making the play four or five yards beyond the line of scrimmage, which is why the Lions consistently allow four or five yards rushing.
Worse, sometimes the corners or safeties are pushing the backs out of bounds 20-plus yards downfield.
But on the whole, the back seven's athleticism and swarming approach are doing a great job of slowing opponents' running attacks until it's a moot point, never allowing the backbreaking big play.
Of course, that's the true design of the Lions defense: to allow teams to run, while the Lions offense passes to victory. The Lions are engineered from the ground up to get a lead quickly and build it from there. As Matt Forte and the Chicago Bears found out weeks ago, running for 5-plus yards per carry won't help if you're playing catch-up with the Lions offense.