The New Orleans Saints lost their grip at the top of the NFC South on Sunday with a 24-15 loss to the Atlanta Falcons.

The Falcons are now the unlikeliest division leader while the Saints are looking like one of the NFL's biggest underachievers.

What went wrong against Atlanta? Who is to blame for the losing record?

3. Defensive line

Defensive success is usually governed by two simple concepts: Can you get to the passer? And can you stop the run?

The Saints did neither against the Falcons.

New Orleans' defensive line is at the root of the problem. They generated zero sacks against a team that came in giving up an average of three sacks per game. The lone QB hit for the defense came courtesy of a defensive back: Tyrann Mathieu.

That's not a terribly big surprise. The Saints have been one of the worst teams in the league when it comes to generating pressure this season and second worst with just 18 sacks. They're making it too easy on opposing quarterbacks and it's killing them.

On top of that, the Saints gave up 228 yards rushing to the Falcons. That's the most Atlanta has managed this season and the most New Orleans has given up. Saints fans need to hope this was an outlier rather than a sign of worse things to come.

2. Derek Carr

The decision to bring Derek Carr to New Orleans looks worse with each game.

The quarterback passed for 304 yards but failed to score a touchdown for the second consecutive game. Even worse, he gifted the Falcons a touchdown with a red zone interception that Jessie Bates III returned 92 yards for the score. To say the throw was ill-advised would be an understatement of epic proportions. A veteran quarterback like Carr should know better.

The red zone struggles for Carr were a massive issue in general. He racked up those passing yards because the Saints were able to move the ball down the field fairly well. But they couldn't cap drives with touchdowns, settling for six field goal attempts. Blake Grupe hit five of his kicks, but field goals weren't enough to keep the Saints in the game.

The frustrating thing is the game was within reach. Even slightly better red zone efficiency wins the game for New Orleans. This is the kind of game the Saints will rue at the end of the season if they miss the playoffs.

Carr's red zone inaccuracy and penchant for setting up his receivers to take big hits cost the Saints against the Falcons. He's not worth his contract at this point.

1. Dennis Allen

It's tiring for this to be the same story week after week, but there's no getting around it. Dennis Allen is the problem in New Orleans.

The Saints are not a competitive football team. Their 5-6 record is a reflection of the light schedule more than anything. Those five wins came over the Titans, Panthers, Patriots, Colts and Bears. Indianapolis is the only team in that group with a winning record this season. Carolina, New England and Chicago have six wins between them.

The issues on offense are well documented. Allen retained Pete Carmichael at his own peril and decided to bring him back in 2023. The head coach doesn't get a pass on that decision.

The biggest concern is on defense though. Allen is only the head coach of the Saints because of his performance as a defensive coordinator. Now, New Orleans' defense is regularly giving up scoring drives late in games when they desperately need stops.

It's been said and it will continue to be said. The Saints hired a head coach with an 8-28 record in Oakland. They gave him another chance and he finished third in the NFC South despite taking over a team that hadn't finished outside the top half of the division since 2016.

Now, an incredibly flawed Falcons team is in the lead in a shockingly weak NFC South. And the Bucs aren't far behind in third place. Allen's excuses are hollow.