FOXBOROUGH, Mass. (AP) — The dominance of the Patriots' defense was at the center of each of their eight consecutive victories to open the season.
Its knack for forcing turnovers, limiting opponents' rushing yards and ability to force three-and-outs helped it demoralize opposing offenses on a weekly basis.
It did show some vulnerability during New England's lone loss of the season to the Ravens in Week 9. But the Patriots (8-1) still boast one of the NFL's best defensive units as they prepare for the second half of the season.
With no defensive coordinator and coach Bill Belichick calling the plays, a veteran group of self-proclaimed "Boogeymen" linebackers and ball-hawking secondary lead a defense that is allowing a league-low 11 points per game and has forced an NFL-best 27 turnovers.
But after facing a mostly soft schedule over its first nine games (opponents were a combined 21-43), New England will return from its bye staring at its toughest four-game stretch of the season. Those opponents — Philadelphia, Dallas, Houston and Kansas City — have a combined 22-13 record.
It's a challenge New England's defense says it's ready to confront.
"We can't think we're going to fix every problem we've had during the season, during the bye week; it just doesn't work like that. I think if it did, you'd see a lot of better football teams," safety and captain Devin McCourty said. "It's not the first game we've ever lost."
Nor is it the first time the Patriots' defense has dealt with criticism in recent years.
It spent most of the 2018 season trying to prove that the departure of defensive coordinator Matt Patricia wouldn't prevent it from developing into a championship-caliber unit.
Following a slow start, it did just that under Brian Flores, who helped it become one of the league's stingiest defenses by the end of the regular season. It went on to shut down the Rams in the Super Bowl to help secure New England's sixth Lombardi Trophy.
After Flores departed this past offseason to become Miami's head coach, Belichick tapped former Tampa Bay Buccaneers coach Greg Schiano to be his new defensive coordinator.
But Schiano asked to leave the job for family reasons after just two months. Instead of finding a replacement, Belichick decided to take over play calling for the defense himself.
He also brought in former Patriots linebacker Jerod Mayo to coach the inside linebackers.
Safety Duron Harmon said having Belichick assume play-calling duties only amplifies the presence he's always had.
"It's his defense," Harmon said. "He's ran this defense for a long time. So he's always had input. I've had different defensive coordinators since I've been here, so we're kind of used to dealing with change."
And adapting to it.
While Belichick hasn't altered much about the defense's alignment over the past three seasons, he has tweaked it this season.
The Patriots still play a higher percentage of man-coverage sets than any other team in the league and the zero-blitz — or not using a deep safety to protect the back half of the field — is still one of its hallmarks.
But New England has switched from a base 3-4 alignment to a 4-3.
That's helped linebackers Jamie Collins, Dont'a Hightower and Kyle Van Noy move more freely in the middle of the field and created more opportunities for them as run stoppers.
Another byproduct has been the creation of an overall atmosphere for forcing turnovers, which has become the Patriots' calling card. There is now an expectation among members of the defense to "hunt the football," McCourty said.
Collins, Hightower and Van Noy collectively have forced five fumbles and have four fumble recoveries. Collins also has three interceptions — a career high.
Meanwhile, the secondary has excelled on the back half on the field, benefiting from the pressure the front seven is getting on quarterbacks to capitalize on errant passes. New England's defensive backs have been responsible for 13 interceptions.
The result has been opponents having to alter their game plans.
Browns receiver Odell Beckham Jr. said they went into their matchup against the Patriots with an aggressive plan to take shots down the field in the passing game. It didn't happen.
"I just felt like we didn't challenge as much as we could have," Beckham said. "I think we kind of shied away from it."
Among the factors that likely contributed were Cleveland's three consecutive turnovers in the first quarter that put the Browns in a 17-0 hole.
Hightower said turnovers are a carrot they chase each week in their attempt to shut down opposing offenses.
"Whenever we go out, we have the attitude that there's no reason why we can't force them to go three-and-out, there's no reason why we can't get a pick on the first play, there's no reason why we can't knock the ball out," he said. "Whenever you have 11 guys on the field that are conscious of the ball or the quarterback and running back, good things happen."
Follow Kyle Hightower on Twitter at https://twitter.com/khightower