Chiefs defensive success trends at the bye week

Every week I come up for air out of The Laboratory to give you the numbers on what the Kansas City Chiefs defense did in the previous game.

This year, it’s typically been pretty poor — with a few bright spots here and there.

However, as we go from week to week, the problems shift. Some things get corrected. Others start to rear their ugly heads. And some just stay the same. It’s sometimes difficult to look back on the year and wonder where the fixes have been implemented.

Now that we’re at the bye week, it’s as good a time as any to show the defensive success trends that have occurred throughout the year. We’ll look at some of the relevant statistics for the Chiefs defense by using one of my new favorite methods — defensive success rate.

For the uninitiated, defensive success rate is a base formula utilized by Football Outsiders to look at each play from a situational standpoint. For a defense, a successful play is defined as holding an offense under 45 percent of the yardage to gain on first down, 60 percent of the yardage on second down or 100 percent on third or fourth downs.

This metric improves on the simple “yards per play” statistic by considering the situation in which the defense finds itself. A 9-yard gain allowed by the defense is bad on first-and-10, but it’s typically good on third-and-17. Including the game situation on the measurement of each play adds revealing context to the numbers.

With that out of the way, let’s go through some of the spots where Bob Sutton and the Chiefs defense have been praised — and criticized — this season, and look at how they’ve varied from week to week.

Success trends

By quarter

Through the first five weeks of the season, this Chiefs defense was absolutely lights-out in the first quarter of the game. Not only were they keeping points off the board, they were finding success on over 60 percent of the snaps they saw, resulting in more three-and-outs and bigger early leads. Then in Week 6, the New England Patriots happened.

It’s interesting to note that the Chiefs’ two losses — Week 6 against the Patriots and Week 11 against the Los Angeles Rams — are two of the three worst first-quarter performances by the Chiefs defense. The other was Week 8 at home against the Denver Broncos. In that game, the Broncos were able to move the ball on the ground for the whole game, but couldn’t finish drives well enough to keep up with the Chiefs offense.

It’s worth noting that after a poor start, the Chiefs have responded well coming out of the half. Outside of the aforementioned Broncos game, the Chiefs have shown quite a bit of improvement in the third quarter since Week 5. The fourth quarter has been difficult to gauge due to some garbage time stats — the second-lowest success rate of the year came in the Cincinnati Bengals blowout — but over the last few weeks, the Chiefs have closed well when they’ve needed to do so.

Finally... I have previously mentioned my optimism about the Chiefs defense after the Rams game. Outside of the first quarter shellacking they took, the Chiefs defense shored up their stop unit on a play-by-play basis. There were certainly some long plays given up, but on the whole, they had some of their best performances of the year in quarters two through four against the Rams.

By down

While the Chiefs are definitely still best on third down this season, they’ve certainly cooled down from the blistering success rate they had early in the season. First and second downs haven’t been their strong suit, but they’ve slowly been trending upwards since the Week 8 Broncos matchup. Fourth downs happen sporadically — so the wild swings are due to small sample sizes — but have generally been in the offense’s favor.

Interestingly, the three worst first-down success rates of the year all came against AFC West opponents. On top of that, every single game where the Chiefs defense had a first down success rate under 50 percent was against teams that played a higher percentage of 12 and 21 personnel — which means we add the San Francisco 49ers and the Patriots to that list of AFC West teams.

The past three weeks have shown more positive consistency on early downs to go along with the typically good third down success rate. With run-heavy teams on the horizon that will utilize heavier personnel packages, we’ll see if the Chiefs can continue to build on the recent success rate, or if they’ll fall back in line with some of their poorer performances.

By formation

The Chiefs have committed themselves to the 2-4 Nickel defense this year, running it 53.4 percent of the time. That’s double the percentage that the Chiefs base 3-4 defense is run (22.2 percent) and almost three and a half times more than the Chiefs run their 2-3 Dime defense (15.6 percent). The 3-3 Nickel is the only other defense that is run with any real regularity — and at 5.7 percent, it’s not that often.

What might surprise you is how poorly the Chiefs have run their 3-4 defense throughout the year. Only twice have they been better than break-even in that formation. Once was in Week 2 against the Pittsburgh Steelers, who completely abandoned heavy formations early, leaving the Chiefs to run the 3-4 less than five percent of the game. The other was against the Cleveland Browns, and that success rate was just above 50 percent.

The 2-4 Nickel had its worst two performances in the Chiefs’ only losses. That’s no surprise — given the frequency with which the Chiefs nickel package is used, and the way the opposition was able to move the ball in those games. The best performance from the Chiefs 2-4 Nickel? That came in the Chiefs’ defeat of the Arizona Cardinals — and it also featured Dorian O’Daniel next to Reggie Ragland.

The 2-3 Dime defense was run fairly infrequently early in the year. The Chiefs were lacking in trusted safety depth, and in the early going, didn’t have a coverage linebacker on whom they depend. Starting in Week 7, Sutton began leaning more heavily on O’Daniel and Jordan Lucas in the dime linebacker roles. Since then, the dime has become more of a staple for the Chiefs defense, and it’s been slowly improving — even with some poor play when Daniel Sorensen replaced Lucas.

Against the run

There’s are no two ways about it: the Chiefs defense absolutely struggles to stop the run.

They’ve had some very poor performances against the run — specifically against AFC West opponents. As we see here, outside of the Steelers game, the Chiefs have been largely abysmal on a play-by-play basis. In almost two-thirds of the games, the opposition has been able to move the ball on the ground with a success rate above 50 percent.

It’s not just against the sub-packages, either. Only the 2-4 and 3-4 defenses have been used in more than seven percent of the rushing attempts this season, so the bulk of the attempts are shown above. While the 2-4 defense hasn’t been great against the run, it’s certainly been better than the base 3-4 that the Chiefs use. In the offseason, the Chiefs added multiple nose tackles, a couple of new inside linebackers, and a run-stuffing edge defender — but they still can’t line up in the base defense against heavy personnel and stop the run. That could come back to bite them if an opponent commits to it late in the season — or (God forbid) in the playoffs.

Against the pass

One of the major knocks I hear on Sutton is his propensity to rush three players against the pass, leading to soft zones and poor performances. While the above success rates may show some of those failures, the Chiefs just aren’t doing it very often — just 12.5 percent on the year. Weeks 2, 6, 7 and 8 had the highest implementation, while Weeks 3, 4, 5 and 10 had the lowest.

Conversely, Sutton has blitzed more this year than last year — even with a pretty solid four-man rushing rotation. 14.5 percent of the passing snaps have seen a rush of five or more, while over 30 percent of the snaps have seen a second or third-level blitzer. Perhaps the most surprising element of the extra rushers is the success the Chiefs are achieving with them. Against some notoriously good blitz-beating quarterbacks and offensive coordinators, Sutton has timed and disguised blitzes well; when blitzing this season, he’s never had a success rate under 50 percent in any game.

After starting the season with some question marks rushing the passer, the Chiefs preferred four-man rush — which has been run on 73 percent of the passing snaps — has fared well. After Week 2, only Tom Brady in Week 6 and Baker Mayfield in Week 9 were able to have more successes than failures against the Chiefs four-man rush. Houston’s return should continue to keep the overall success rate high — but especially when the Chiefs rush four.

There has been a lot of discussion about the quality of the Chiefs cornerbacks, and what this defense is getting out of these players. The mashup of Kendall Fuller, Steven Nelson, and Orlando Scandrick has been significantly better than most expected this season. Nelson leads the three with an overall 61 percent success rate, followed by Fuller at 59 percent and Scandrick at 57 percent.

Fuller’s week-to-week numbers are interesting because he wasn’t targeted much in the first three weeks of the season. Week 4 against Denver was a great performance, but then he went through four weeks in which he had struggles against Jacksonville, New England, Cincinnati, and Denver again. I said in the post-game write up for the second Broncos game that I thought Fuller looked like he was turning it around, and in the past three weeks he has. He’s been most successful in Sutton’s Cover 3 looks and Cover 2 man looks, posting 84.6 percent and 85.7 percent success rates in those formations.

With his sustained success this season, Nelson might be the biggest surprise of the three. While he and Scandrick have caught a number of penalties for their physical (and grabby) play, on a target-by-target basis, Nelson has been consistently good. He’s been targeted three percent more often than any other player on the roster, yet still has the highest success rate among the cornerbacks. He had a poor Week 3, and was beaten up a bit by Courtland Sutton and Emmanuel Sanders in Week 8, but by and large, he’s been very good. It’s no surprise that he’s finding most of his success in Cover 1 and Cover 2 man looks.

Scandrick is the one I am watching most closely. After starting well, he had a poor Week 4 against Denver. He played above the break-even mark during Fuller’s poor stretch — but just barely. The Week 8 spike was on his lowest target share of the season — just 4.8 percent. When he’s been targeted heavily over the last three weeks, he’s showing a little bit of his age. This late bye week may help rejuvenate him and help him get back to his early-season form. His highest success rates are in the Cover 2 and Cover 3 zone looks.

It’s difficult to use the success rate metric on safeties and linebackers because it doesn’t always fully capture their responsibilities on a play. For instance... if the deep safety doesn’t get over to help a cornerback in a Cover 1 shell, the safety isn’t penalized for it.

So take the following with a grain of salt:

Ron Parker has notched a 42.8 percent success rate on the season — best in Cover 3 and worst in Cover 1. Eric Murray has a 46.6 percent success rate with the same best and worst as Parker. Anthony Hitchens has been poor, with a 34 percent success rate — despite being the fourth-highest targeted player on the team. All other safeties and linebackers left haven’t been targeted above 3.5 percent of the time, so data can be skewed by outliers a little more readily.

In conclusion

While none of this is new information, it is something that I’ve been keeping track of through the year. Looking at it in this form — at this time of the year — can be quite interesting.

I think the past few weeks have shown steady improvement in early downs and middle quarters. We’ve seen a better pass rush and growth from the Chiefs’ top two cornerbacks.

The defense still has major struggles to fix with their run defense and safety play, but there’s some hope that successes will become more common when Eric Berry is able to return.

I think this team is finding its groove as an OK defense late in the season, and some consistency is starting to show up in some of the success rate metrics. With an easier schedule on the horizon — and returning players — let’s hope that at the end of the season, we can look back on this moment and see it was a jumping-off point towards further success.