The 2011 Dallas Cowboys Defense: A Tale of Two Halves

In the last few games, the patented eyeball test has indicated that the Cowboys defense hasn't been as stout as it was the first month of the season. As I noted in my "Quick takes" post following the Arizona debacle, my impression in in recent weeks has been that the Dallas defense has been plagued by a couple of problems: First they have tended to be a break-but-don't-bend unit; second, they have been good early in games, but have struggled after halftime. As I like to do when I have the time, I wanted to do a bit of research to determine the accuracy of the in-game eyeball test which, as we know all to well, can be tainted by the emotion of the game.

I did some quick research, focusing specifically on opponent's drives, with some interesting (and depressing) results. A couple of general thoughts before we get to specifics: 1) We can divide the season into two halves of six games each, with the pivot being the game at Philadelphia. The Dallas defense, a pretty salty unit, even while losing in, say, New England, has been a different unit since the Eagles game. Since then, they have surrendered more yards, more long drives, and more late-game points than in the first six games. 2) This last point suggests that opposing offensive coordinators have been making effective halftime adjustments of late, which have let to significant difference in second-half productivity versus the Cowboys defense.

I want to look at three or four specific areas: yards surrendered by half; the distance of opponents' drives; Dallas' YPA numbers; and when Ryan's troops are notching boot-on-the-neck series (i.e., three-and-outs). All of this and more after the break...

Long drives: On the season, the Cowboys have allowed 30 drives of 57 or more yards. 11 of these happened in the first six games; 19 have happened since the Philly game. In early-season contests against San Francisco, Washington and Detroit, they yielded one each of these long drives. Since that game, they have given up at least three such drives in every game save the second Redskins tilt. Perhaps more troubling is when these long drives have happened, especially in the last six games. The Eagles had four such drives in the first half; since then, eleven of the 14 long drives allowed by the Dallas D have come in the second half of games.

Why is this? There are several possible explanations, all of which are likely contributing causes: 1) Opposing offensive coaches are figuring out Ryan's schemes, and making adjustments. Once they do, he lacks a counter-move. This leads to 2). The Cowboys success depends so heavily on scheme (as opposed to talent) that, once rival OCs figure out Ryan's game-plan, the Dallas defense, which cannot win one-on-one matchups, is toast. We certainly saw this on Sunday; once they figured out his pressure packages, the Cardinals could isolate weak points (Terence Newman, cough, cough) and exploit mismatches.

Second half yardage galore: As the above would suggest, the Cowboys hare giving up more yards after halftime than they are before it. In the first six games of the season, they gave up almost exactly as many yards in the first half (860) that they did in the second (874). Since the Philly game (and not including it), 66% of their yards (577 to 1160) have been given up in the second half of games. 577 first-half yards in five games is fairly stout; 1160 second half yards? Not so much.

YPA decline: All season, one of our most statistically-inclined readers, Fan in Thick and Thin, has been tracking the Cowboys' net pass Yards Per Attempt stats, as a way to mark the effectiveness of their passing game, on both sides of the ball, against the rest of the league. Earlier today, he published the latest numbers, some of which I have purloined below, with his permission. Note that the NFL average YPA in 2010 was 6.1; thus, an offensive average above 6.1 is good, and the defense wants to be below 6.1:

As we can see, the Defensive YPA has increased steadily since the Philly game. Before that, the only contest in which the Dallas defense was above the league average was game one, against the Jets. Since the Philly game, with the exception of the Buffalo tilt, arguably their most complete game of the season, they have been above the league average--and often well above it. More troubling is that their numbers have increased steadily in the past three weeks (while the offensive numbers have decreased, but that's a topic for another post).

Three and outs: As many of you may have gleaned, I like to track three-and-outs. I find them significant; a situation in which the defense stops the offense in the fewest plays possible and gives the ball back to the offense is just short of ideal (that would be causing a turnover, preferably with a healthy return). In the seasons first six games, Ryan's units registered 7 first half three-and-outs, and notched 8 of them in the second halves of games. Since the Philly game? 13 first half three-and-outs, and 2 in the second half. To my mind, that's a telling and troubling transformation.

Breakin' but not bendin': When the Cowboys don't manage a three-and out or, just short of that, give up only a single first down, they tend to give up long drives. This is in stark contrast to what the Cardinals' defense did on Sunday, when they repeatedly gave up 30+ yards on drives, but rarely gave up more than 40. In other words, they found a way to keep the Cowboys out of, or right at the outer limit of, scoring range. Twice, the Cowboys drove between 30 and 40 yards (on drives of 34 and 36 yards) and had to punt; a third time, they moved it 37 yards only to miss a FG.

Dallas has been hard pressed this season to do the same. In twelve games, they have forced a punt after the opposition has driven 30 or more yards exactly three times. All of these happened in the first six games. To be fair, they have curtailed seven such drives via turnover (4 of those have come in the season's second half) and forced missed field goals on for other occasions (three since the Philly game). Against Buffalo, they stopped a 66-yard drive on downs but, had the game been closer, that would surely led to a field goal attempt.

So, what can we make of all this information? It seems pretty clear that, since the Eagles game, the Cowboys defense has been on the decline, especially in the second halves of games. Did the Eagles offer the rest of the league a blueprint for beating Ryan's schemes? Did they miss Mike Jenkins, who went out with an injury against Philly? Did that butt-whipping leave the coaching staff scared, or shell-shocked, and did Ryan--and, by extension, his charges--lose his patented swagger?

Its probably a mixture of all of these factors. Whatever the case, this is a trend that has to stop if the Cowboys are going to do anything with the rest of their season. On their current trajectory, the 'Boys are going to struggle to win any of their games--and, honestly, risk further blowouts akin to that terrible, forgettable Sunday night in Philadelphia.