New Orleans Saints defensive tackle Sheldon Rankins (98) pressures Chicago Bears quarterback Mitchell Trubisky (10) during the first half Sunday, Oct. 29, 2017, at the Mercedes-Benz Superdome.

You can’t label the New Orleans defense as anything.

Putting them in a box would be too simplistic. At its core, yes, this is a 4-3 defense. That’s what the depth chart says, and if you were forced into describing the base defense, that would be the proper way to go about it.

In practice, however, it’s much more complicated.

New Orleans has only played 116 snaps with 4-3 personnel on the field this season, or about 25 percent of the time. If the defense stuck with a four-man front in nickel packages, the label would work a little better. That isn't entirely true, either.

The Saints change and morph on a week-to-week basis, and sometimes multiple times throughout a game. We’ve seen New Orleans in plenty of three- and four-man fronts this season, and after seven games, it felt safe to assume how those packages would look and operate.

But during Sunday’s 20-12 win over the Chicago Bears, defensive coordinator Dennis Allen introduced another new wrinkle.

New Orleans often mixed in a three-man front, with three down interior defensive linemen and two defensive ends standing up on either side. The interior linemen often included John Hughes, Sheldon Rankins, David Onyemata and Tyeler Davison, with Cam Jordan, Trey Hendrickson and Alex Okafor serving as the outside players.

Typically, this package had only one linebacker on the field and five defensive backs. One of the reasons the Saints went light at linebacker on these plays was because safety Kenny Vaccaro was freed up from covering the slot this week and served as a strong safety.

This was different from the three-man fronts New Orleans often used against Detroit on Oct. 15. The primary goal of that package was to disguise where pressure would be coming from, which wasn't always the case Sunday against the Bears.

Chicago is predominantly a running team, and this look allowed the defense to keep some heavier personnel on the field alongside its pass rushers.

It also created another front for a young quarterback, Mitchell Trubisky, to read and diagnose, which at times caused him problems.

New Orleans used this look on 22 plays and had a good amount of success. Trubisky attempted 13 passes against it, completing four for 65 yards with one sack. The Bears also ran against the front eight times for 8 yards.

The sack came with a slight tweak. Hendrickson, who beat guard Josh Sitton to make the play, lined up as an end in the three-man front instead of one of the interior defensive linemen.

The Saints’ other sack also came out of a three-man front, but that one was more in line with how the defense operated against the Lions.

Jordan, Rankins and Okafor operated as the down linemen, with linebackers Craig Robertson and A.J. Klein and safeties Vonn Bell and Rafael Bush also in the box. The linebackers dropped into coverage, while the safeties blitzed. Vaccaro also blitzed and had a free path to Trubisky, where he and Cam Jordan met the quarterback at the same time.

The varying looks caused some confusion for Trubisky. On at least two plays, he anticipated a blitz or was unable to identify where pressure was coming from, and he threw the ball away. He also hurried a few throws to open receivers that fell incomplete.

Outside of a couple explosive running plays, the defensive line had several good moments throughout the game. Onyemata shined at times against the run, eating blocks that allowed others to flow and stuffing two runs himself. In the passing game, Rankins had at least five pressures in what might have been the best game of his career — including one off a nice spin move — and Davison had two.

Okafor and Jordan both made a handful of plays against the run, and all three ends each had at least two pressures.

At this point, it’s becoming clear that you can never quite know what Allen might cook up. He’s going to tailor his approach each week for the upcoming opponent, and often there will often be surprises. As well as the defense is playing, a lot of the credit needs to go to the guy designing the scheme each week.

VACCARO KEEPS ROLLING: After Sunday’s game, Vaccaro said he wanted to remind everyone what he can do in the box after spending the last few weeks covering the slot. He easily made his point.

The safety had four run stuffs — two of which came after he shed a blocker and got into the backfield to drop the running back. He also picked up partial credit on a sack and made a key fourth-down play in coverage in the fourth quarter by breaking up a pass (partial credit to Rankins for making Trubisky step up in the pocket and hurry a throw).

Since having what he calls a “bad second half” against the Vikings in the season opener Sept. 11, Vaccaro has arguably been playing the best football of his career, and it keeps showing up every week.

LATTIMORE SHINES: It’s worth buying an "NFL Game Pass" subscription just to watch how Marshon Lattimore defends players. The ball doesn’t often come his way, and it’s easy to see why.

The plays where nothing is happening are often his best ones. One of those moments on Sunday came when Trubisky rolled out, and Lattimore had the awareness to get between his man and Trubisky and squeeze out the passing lane as the quarterback continued to approach the sideline. The corner kept his eyes on the quarterback the whole time and continued to shrink the field with his angle. Trubisky eventually threw the ball away.

The same recognition showed up on his interception. It was an errant pass, but it was only picked off because the cornerback kept his eyes on the quarterback and peeled off instead of following his receiver over the middle.

It’s getting difficult to describe how well Lattimore plays each week. His recognition in zone coverage keeps getting better, and the Saints are starting to roll safety help away from him. He has only played in six games and is already flashing the ability to lock down his side of the field. This was another week in which he did not surrender a catch.

HICCUPS: This wasn’t a perfect game by the defense. There were probably a few too many hiccups for comfort.

The two obvious ones were a 50-yard run by Jordan Howard and a 46-yard run by Trubisky. On the Trubisky run, New Orleans got caught in a blitz, and Marcus Williams was just a step slow in getting to the quarterback in the backfield. Howard was able to hit a gap, no one was home on defense, and Trubisky took off.

There were also a couple of broken coverages. One, which led to a 25-yard gain, came when two players picked up one tight end and let Tre McBride run free for an easy completion. New Orleans also dodged a bullet when running back Tarik Cohen got wide open down the field, and Trubisky just missed a pass to him.

McBride also got open for a 45-yard reception, and it looked like Ken Crawley, who otherwise had several standout moments, got frozen watching the play and didn’t drop back to help Williams in coverage.

These plays can’t happen if the Saints hope to win against better teams.

PLAY OF THE GAME: The Saints pulled out a nice bit of deception on a 19-yard pass to tight end Josh Hill. The Saints were in "21" personnel, with two running backs and two tight ends, and appeared to be attempting a screen pass. The Bears' defense was pulling to the right side of the field when Hill snuck back inside and ran up the seam for an easy reception.

It looked real enough that it almost looks like the screen busted and Hill changed things up on the fly.

SECOND PLAY OF THE GAME: Drew Brees' 34-yard back-shoulder pass to Alvin Kamara was about as good a throw as you'll see all season. Brees noticed the safety watching him, so he hitched to hold him for a second, and then dropped a pass that caused Kamara to stop and turn to make the catch. If he had led the running back, it would have been an easy interception.


COOL BREES: This was a very strong performance by Brees. He was extremely efficient, didn't take unnecessary chances and took all the yards that were available. There were times he wanted to go down the field, but the opportunities weren't always there, and he'd "settle" for an underneath route. His willingness to get rid of the ball or throw it away when nothing was there was key to the performance. It's interesting to watch, and one has to wonder if Brees would be taking the same approach if the defense wasn't playing as well.

MORE NORMAL: The offense got back to normal this week, in that there were more passing plays out of "11" personnel than what has become standard this season. It's hard to know if that played a role in things clicking a little more, but that's what has worked in recent seasons. Against a good defense, the passing offense played well, which is a good sign moving forward.

On the other hand, it's notable that with so many three-receiver sets being used, Willie Snead was only on the field for four snaps.

QUALITY ADJUSTMENT: Ted Ginn Jr. has done many things well, and already has proven to be an improvement over Brandin Cooks after the catch. But one of the things that stand out is his ability to adjust to the ball when it's in the air. For the second week in a row, he bailed Brees out on an underthrown pass deep down the field. This time, he pulled it in for a gain of 53. Brees made the throw under pressure, and it was one of the few chances he took during the game that was questionable.

SOME PRESSURE: The Bears were a good test for the offensive line. Brees was pressured on about 10 of his snaps and handled it well. He was forced to run from it once and took a couple of sacks, but his passing was fine. The line has held up well this season, and this was one of the few times this season when it felt like there was notable pressure. 

Follow Nick Underhill on Twitter, @nick_underhill.​