METAIRIE, La. -- The New Orleans Saints defense is making NFL history this year.

That's not a good thing.

The Saints (4-5) are on pace to allow the highest opponents' passer rating of all-time (112.0), according to the Elias Sports Bureau. The current record of 110.9 was set by the 0-16 Detroit Lions in 2008.

At least the Saints have some company -- the 2015 Lions are also on pace to break the record (111.1).

Big play -- like the touchdown pass given up to Delanie Walker -- have haunted the Saints defense all season. Jonathan Bachman/AP Photo

When asked about that dubious distinction, several Saints players had trouble deciding whether they believe it sounds accurate.

The general consensus was they aren't really that bad, but they've been too inconsistent and have allowed way too many big plays.

New Orleans has allowed a league-high 11 pass plays and six touchdown passes of 40-plus yards.

"I feel like we're hit or miss," safety Jairus Byrd said. "One game we come out, we look lights out. Then the next game we come out and it's like we're just, ‘What is this?'"

Last week was a perfect example. The Saints forced six three-and-outs during a 34-28 overtime loss to the Tennessee Titans. But they still allowed quarterback Marcus Mariota to throw for 371 yards and four touchdowns.

Byrd managed a laugh when asked how unusual it is that the Saints actually have the NFL's fourth-best defense on third downs this year -- opponents have converted only 32.7 percent.

"That's kind of weird, it's kind of an anomaly," Byrd said. "If we do get you to third down, watch out."

The QB rating isn't the only historically-bad mark for the Saints' defense.

They are also allowing a league-high 6.47 yards per play -- which Elias says would be the most since the 1961 Minnesota Vikings (6.51).

And the Saints just became the fifth team ever to allow at least four passing touchdowns without an interception in consecutive games (versus Eli Manning and Mariota).

"I don't know, man," safety Kenny Vaccaro said. "I mean obviously we don't want to be the highest rating ever. But I don't see us as that. That's an interesting stat.

"We gotta get better. I mean, it's obvious, it's kind of a no-brainer. We just gotta get better. We just gotta stop giving up the big plays. We make the good plays, and then we give up some bonehead type plays, you know?"

Among the "bonehead" plays Vaccaro referenced were last week's collision between Byrd and cornerback Keenan Lewis that turned a sure interception into a 61-yard touchdown for Tennessee's Delanie Walker; another collision between Byrd and Vaccaro on a 41-yard touchdown by the Philadelphia Eagles' Josh Huff; and two plays where cornerback Delvin Breaux slipped and fell to allow deep scores to the Indianapolis Colts' T.Y. Hilton. Vaccaro said there have been more traditional busted coverages, as well.

"It's just a number of games when the ball goes up, we need to start coming down with the ball more and not bouncing off somebody's head, getting tipped, falling down," Vaccaro said. "People say it's a fluke play, but it's happening over and over. So is it a fluke anymore?

"Quarterbacks can't just throw up the ball and know, ‘OK, it's either gonna be an incompletion or we're getting the ball or a penalty.'"

Penalties have also plagued the Saints -- especially fouls on cornerback Brandon Browner, who leads the NFL by a wide margin with 17 called and 15 accepted.

But it's not just the secondary that has struggled. Not even close.

The pass rush was way too easy on Mariota last week with zero sacks. And the injury-riddled linebacking corps got burned repeatedly by tight ends.

"It doesn't just fall on the corner. The pressure falls on these inside linebackers and the guys playing underneath it," Saints coach Sean Payton said when asked why there has been so much inconsistency with New Orleans' pass defense after they made a switch to more man coverage with a single-high safety.

The Saints felt it would be a better use of the cornerbacks' size and skills. It was also a simplified approach that Payton wanted to install after defensive coordinator Rob Ryan's more complicated schemes led to too many mental errors last year.

"I think it fits who we are from a corner perspective, when you look at our size and you're talking about Keenan, Brandon and Breaux," Payton said. "Now, the nuances within it, and there are quite a few, we've got to be better at."

Saints defensive end Cameron Jordan copped to the pass rush's part in the loss to Tennessee.

"Yeah, that's something we definitely take pride in (making the opposing quarterback uncomfortable) and have to do a better job of. Clearly it wasn't enough last game," Jordan said. "Zero sacks, a couple hurries, some pressures, but not enough to really make the quarterback worried about what we're doing and where we are."

When asked to assess where that defense is at this point in the season, Jordan said, "I feel that our defense is still learning."

"I wouldn't say that's a great thing at this point. Sitting at 4-5, fighting to get back to .500, lost to a team that we shouldn't have lost to," said Jordan, who was still very salty over losing to the Titans, who were 1-6 heading into the game.

"You never want to lose one, especially to the team we just lost to," Jordan said. "You say you face elite talent every week, but we made Mariota look way, way, way better than we should have. That's just something that you have to stomach for the week."