The Patriots' unrivaled success this century, which includes five Super Bowl titles, has everything to do with the Hall of Fame careers of Tom Brady and Bill Belichick. Unfortunately, neither plays defense, which could not only be the downfall of the Pats in 2017 but could signal the end of a dynasty.

Through four games, New England owns the NFL's worst defense, a point that was slammed home with a resounding thud in Gillette Stadium on Sunday against a Panthers offense that had struggled through its first three games. When it was over, Carolina had scored 33 points and racked up 444 total yards. Cam Newton finished 22 of 29 for 316 yards with three touchdown passes and one rushing touchdown.

And while it must've been a relief for the Panthers to see Newton get back on track, we shouldn't put too much stock in one outing against a group that looked completely lost for much of the game.

NESN's Doug Kyed spent much of his Sunday afternoon tweeting screenshots of just how confused the Patriots secondary was against straightforward Panthers formations.

Here's Kelvin Benjamin all alone at the bottom of the frame:

And here's Devin Funchess running free (again, at the bottom of the frame), completely uncovered.

And perhaps the most egregious blown coverage of the day came when no fewer than four Patriots defenders covered Christian McCaffrey while Fozzy Whittaker sashayed into the end zone:

The movie-pictures evidence is even more damning. Not only is tight end Ed Dixon WIDE OPEN, but so is Whittaker.

The Patriots, whose secondary was supposed to be a strength -- especially after signing cornerback Stephon Gilmore on the first day of free agency -- has been an unmitigated disaster.

Gilmore called the Whittaker touchdown a "communication issue" while safety Devin McCourty was less diplomatic: "Bad play. It had to look like a couple idiots out there."

Safety Duron Harmon added: "It's [communication] obviously something we need to work a little harder at. Obviously what we're doing is not good enough, so we need to go take a look in the mirror tonight and just look and realize. Are we doing enough to win? Are we doing enough to be good on defense? Are we doing enough to be a sound football team? Today we weren't, especially on defense."

McCourty said "you have to be concerned" about the way the defense is playing and cornerback Malcomn Butler talked about the "urgency" of correcting the problems with four games already behind them, which makes it pretty clear where the focus should be as the Patriots prepare for a quick turnaround against the Buccaneers on Thursday.

The Patriots have allowed 105 points in three home games this year, they allowed 124 points at Gillette all of last season. — Kirk and Callahan (@KirkAndCallahan) October 1, 2017 Through four games, the Patriots have allowed 128 points. That's the most in Patriots franchise history. — Mark Daniels (@MarkDanielsPJ) October 1, 2017

If we've learned anything from Brady and Belichick is that it's silly to ever count the Patriots out. But this defense has the makings of a historically bad unit a month into the season -- and with a game in Tampa this Thursday, there isn't much time to fix it.