The Patriots are supposed to be perfect at everything. In August, I went searching for flaws in the Patriots’ dynasty, and I had a hard time finding any. That’s why the 2017 season has been so weird. It’s not that the Pats’ record is bad—they’re 4-2, which might not be as good as many people expected in the preseason, but is still good enough for first place in the AFC East. It’s that their defense hasn’t just been bad; it’s been horrendous:

McCown passed for 354 yds. NE the only team in NFL history to allow a player to throw for at least 300 in 6 straight games, per Elias. #Jets — Rich Cimini (@RichCimini) October 16, 2017

The Patriots allowed an opposing quarterback to pass for 300 yards against them in just four games (including playoffs) last season. They allowed an opponent to throw for 300 yards in just four games in the season before that, and five in the 2015 campaign. This year, they’re 6-for-6 in allowing 300-plus-yard passers. No team has ever been that bad in any six consecutive weeks, let alone the first six weeks of a given season.

The Patriots have been worst in the NFL in total yardage allowed (2,644), yards per play allowed (6.6), first downs allowed (146), passing yardage allowed (1,949, nearly 200 worse than the 31st-ranked Colts team), and adjusted yards per attempt allowed (8.9). They are 30th of 32 in points allowed per game (26.5), and that’s with the help of a few timely turnovers. New England is among the worst teams in the league in sack percentage (24th), opposing completion percentage (27th), and opposing third-down conversion percentage (26th). The 42 points allowed against the Chiefs in Week 1 were the most the Pats have given up in a game this millennium.

This comes a year after New England led the NFL in scoring defense (15.6 points per game) and ranked in the top 10 in most defensive categories. And the front office added to that defense by signing cornerback Stephon Gilmore, who turned in the best season of his career for the Bills in 2016, to a $65 million contract in March. In Gilmore, Malcolm Butler, and Devin McCourty, three of the four starters in the Patriots secondary are Pro Bowlers. So why is everything suddenly falling apart?

I watched every completed pass that the Pats have allowed this season with the hope of pinpointing specific problems. It’s hard, because this defense is bad at everything. It’s bending and breaking; it’s allowing opponents to hit quick passes and get open deep; it’s miscommunicating and losing one-on-one battles in man coverage.

To grasp just how ineffective the Patriots’ 2017 defense has been, check out the following six clips—one from each game in which they’ve given up more than 300 passing yards.

1. 75-yard Touchdown Pass to Tyreek Hill (Week 1 vs. Kansas City)

The Patriots got torched by Alex Smith in Week 1, but perhaps that shouldn’t be surprising—Alex Smith has since transformed into the greatest player in football history. His 368-yard, four-touchdown outing in the Chiefs’ 42-27 win included two 75-plus-yard scores. One was a 78-yard pass to running back Kareem Hunt on a play during which Kansas City ran four verts with a jet sweep play-action. I won’t blame the Pats much for that one—nobody on the planet can stop four verts, and every team should run it on every play.

But this third-quarter Hill touchdown was the result of a bad breakdown:

Gilmore thinks he has safety help from McCourty. McCourty does not think that. This may seem like a freak accident and not a trend, but there have since been a whole bunch of plays that the Pats have allowed just like it.

2. 16-yard Completion to Tommylee Lewis (Week 2 at New Orleans)

Drew Brees racked up 356 passing yards, including six completions of 20 yards or more, in the Saints’ 36-20 loss to New England. Brees, it turns out, is capable of throwing difficult passes accurately. But let’s focus on a pass that didn’t require him to be one of the best QBs in the sport’s history:

New Orleans wide receivers Brandon Coleman and Lewis are stacked on top of each other, with Eric Rowe and Gilmore set to defend them. Coleman sprints downfield while Lewis breaks off his route just a yard beyond the line of scrimmage. Rowe and Gilmore both follow Coleman.

A team doesn’t allow opposing quarterbacks to pass for 300 yards every week without consistently letting them move the ball with relative ease. Sometimes, the Pats’ decision to give up short yardage while covering downfield routes is strategic; here, it’s the result of a dumb mix-up that turns a nothing route into 16 yards and a first down.

3. 35-yard Completion to Ryan Griffin (Week 3 vs. Houston)

I spent about an hour watching every pass that Deshaun Watson threw in this game as I tried to decide which one showed the Patriots doing a bad job. Honestly, the Pats did fine. They had no egregious breakdowns in a 36-33 victory—Watson just played his damn butt off.

In theory, the Patriots should have continued to guard the tight end on the far side of the play above while Watson scrambled. Nobody does that, though, because nobody expects a quarterback to run around for seven seconds and then make a throw 35 yards across the field. I’ll get back to trashing the Pats soon, but for now I’d like to say that Watson is very good.

4. 10-yard Touchdown Pass to Devin Funchess (Week 4 vs. Carolina)

There are more Patriots arguing about who should guard Funchess than actually guarding Funchess on this play:

Funchess motions to the left side of the formation, ending up bunched with two other receivers. Rowe promptly follows Funchess, then seems to realize that his responsibility does not include following Funchess, and gesticulates wildly at the defenders on the left side of the formation. When the ball is snapped, Rowe briefly provides double coverage on Panthers tight end Ed Dickson’s out route. He soon realizes that nobody is tracking Funchess. Cam Newton has made few easier throws all season.

5. 42-yard Completion to DeSean Jackson (Week 5 at Tampa Bay)

This wasn’t a truly bad performance by the Patriots: Jameis Winston had 109 passing yards entering the fourth quarter and then threw for 225 yards across his team’s final three drives. But the Patriots played the end of this game like it was a blowout despite Winston nearly leading the Buccaneers to victory. After missing two second-half field goals, the Bucs lost just 19-14, and they’d gotten to within 19 yards of New England’s end zone when the clock expired on their final drive.

This pass to Jackson came on a third-and-2 with just under 10 minutes left to play. The Pats were an exceptional McCourty tackle away from giving up an easy 89-yard touchdown:

I don’t really know what the defense is hoping to accomplish here. The scenario is third-and-2; Butler is covering Jackson like it’s third-and-22:

When the ball is thrown, Butler isn’t even in the frame:

In one sense, I understand Butler’s logic in playing so far off of Jackson. The Patriots have virtually all of their defenders in the box except for one high safety, and want to ensure that a speedster like Jackson won’t sneak behind them for a big play. But that mentality creates the big play. With eight guys near the line of scrimmage and Butler in space, nobody is within a parsec of Jackson. The Patriots build him a runway and he launches downfield.

6. 44-Yard Completion to Jermaine Kearse (Week 6 at New York)

Most of the quarterbacks New England has faced early in the season have been among the league’s best: Smith is having a hell of a year; Brees is a future Hall of Famer; Winston is a former Rookie of the Year; and Newton was the 2015 MVP. But the Pats also gave up 354 passing yards to Josh McCown, the sixth-highest total of his 15-year career.

On this throw from McCown to Jermaine Kearse, the announcers joked that it looked like Kearse was fielding a punt:

This is basically the same mistake that the Patriots made in allowing the 16-yard gain against the Saints, but this time it occurs 25 yards downfield. Kearse and Robby Anderson run alongside each other for a stretch, then Anderson continues downfield while Kearse heads toward the sideline. In this zone defense, Butler’s responsibility is to defend Kearse as he heads to the boundary. Instead, he sticks with Anderson as if he’s in man coverage.

44-yarder to Kearse was an overload concept vs #Patriots’ cover-3. They run 2 WRs into Butler’s zone. Instead of passing off Anderson to the safety he stays with him, leaves Kearse wide open. Nice route by Kearse to delay his run to the outside. Fools Butler. pic.twitter.com/aGeb1p6fdp — Evan Lazar (@ezlazar) October 18, 2017

As with the clips from the Saints and Panthers games, this all starts with receivers lining up in a bunched set. If an offense puts a bunch of wide receivers in a formation next to each other, the Patriots are liable to lose track of somebody.

The New England pass rush is also problematic here—the Jets have a bottom-tier offensive line, and McCown isn’t especially mobile. Still, the Jets are able to gain a chunk of yards with a slow-developing route.

The Patriots have earned the benefit of the doubt at this point, and head coach Bill Belichick delivered a soliloquy on Monday about how a football team is a work in progress. (Belichick is known for giving terse answers to questions in press conferences, but he’ll talk all day when he is passionate about something.) But what Belichick said is true of every team in the NFL, and the Patriots are worse than just about anybody on defense right now.

Luckily for New England, it has Tom Brady at quarterback. He’s very good, and can often help New England score enough points that the team wins even when the defense falters. But for as brilliant as Brady is, I doubt he can win a Super Bowl alongside a league-worst defense. And if the Pats can’t play a zone without forgetting to guard one of the opposing team’s wide receivers, they’re in danger of having the worst defense in the league.