2011 Chiefs DVOA Analysis Post Mortem Vol. 2: Defense


Your favorite fake football statistician returns this week with a look at the Chiefs defense over the past three seasons. Make no mistake, the loss of Eric Berry was a major positional setback this past season but the real question is where the defensive unit as whole came together, grew more in terms of talent and depth and ultimately overcame the loss of the type of player who looks to fulfill a leadership role. Another great thought to consider, particularly in light of the Brandon Carr question, is whether our defensive secondary has significantly and steadily improved these past few years. Perhaps a minor element to also think about is whether Kelly Gregg’s signing represented an improvement, a step back, or status quo for the Chiefs front 7.

So let’s dive into some good old stat tables, courtesy of Football Outsiders, to see if we glean some answers about the State of the Chiefs, D-wise.

Generally speaking, the story is an encouraging one. According to Football Outsider’s methodology, the Chiefs have gone, over the course of two seasons, from being a rather poor defense, to a slightly above average defense. Most notably, our pass defense has gone from 31st in the league to 17th.

The big picture is that the Chiefs defense is not yet where most of us would like it to be but we definitely seem to be on the right track. Let’s hope the trend continues. With Berry’s return, along with some improvement from the front 7, I suspect it will.

To keep things simple, here’s some copy and paste directly from Football Outsiders that explains  what each of these columns represent (however, in this case, you must think in terms of how good a defense is at frustrating these offensive line efficiencies):

"Based on regression analysis, the Adjusted Line Yards formula takes all running back carries and assigns responsibility to the offensive line based on the following percentages:Losses: 120% value0-4 Yards: 100% value5-10 Yards: 50% value11+ Yards: 0% valueThese numbers are then adjusted based on down, distance, situation, opponent, and the difference in rushing average between shotgun compared to standard formations. Finally, we (i.e., Football Outsider) normalize the numbers so that the league average for Adjusted Line Yards per carry is the same as the league average for RB yards per carry. Defensive line stats (more accurately, defensive front seven stats) represent the performance of offensive lines against each defense, adjusted for the quality of offensive opponents.10+ Yards:Percentage of rushing yards against this team more than 10 yards past the line of scrimmage. Represents yardage not reflected in Adjusted Line Yards stat. Teams are ranked from smallest number of 10+ Yards (#1) to largest number of 10+ Yards (#32).Power Success:Percentage of runs on third or fourth down, two yards or less to go, that achieved a first down or touchdown. Also includes runs on first-and-goal or second-and-goal from the two-yard line or closer. This is the only statistic on this page that includes quarterbacks. Teams are ranked from lowest power success percentage allowed (#1) to highest power success percentage allowed (#32).Stuffed: Percentage of runs where the running back is tackled at or behind the line of scrimmage. Ranked from most stuffs (#1) to fewest stuffs (#32)."

Basically, what I think you can take away from this is that the 2011 Chiefs front 7 still has its work cut out for it, particularly when it comes to stuffing the run and getting to the passer.  That said, they have made a lot of progress in terms of controlling the damage we’ve seen done in previous years when it comes to giving up big plays on the ground. In 2011, Chiefs opponents were not regularly taking it the house, week in and week out, like we’ve seen in so many previous years.

Here we see how much teams liked to run against the Chiefs and how successful they were when they did. This is pretty simple stuff actually. In 2011, opposing offenses liked to run a lot against the Chiefs relative to other NFL defenses and when they ran against the Chiefs, they saw the most success running either between the guards or between the right guard and the right tackle. The main thing this suggests to me, and also keeping in mind that the Chiefs are among the softest at stuffing the run, is that they desperately need to upgrade their nose tackle . . . and if not, then perhaps consider returning to a 4-3 defense as the base set.

Now, this table ties back to the two previous ones and tells us a little bit more about how successful opposing offenses were at exploiting the Chiefs’ soft spots.  Bottom line: opposing teams love to run straight at us. The reason? Because they can. What we want to see, is other teams sticking close to the league averages in terms of lane preferences. In other words (or as some might say “another words”), that would tend to suggest the Chiefs are more or less equally strong (or equally weak in the alternative) against the run all along their front 7.

Here we gain a little insight into the job the Chiefs defensive secondary, and linebackers in some cases,  are doing when called upon to cover.  This is, again, a positive tale for the most part. Carr and Flowers are doing an excellent job shutting down #1 WRs and also slot receivers, believe it not. The most glaring, obvious, and ongoing defeciency is the Chiefs inability to cover RBs on pass plays.  Scheme or talent? I tend to think the latter because if our front 7 did a better job at the pressuring the QB, there generally would not be enough time to identify and target that 4th or 5th read.

So there you have it. Resign Carr, get a real, honest-to-god nose tackle, and bring the rush.

That’s my Double Take.

What’s your take, Addicts?