The Patriots defense is the best the Bears have faced this season and should provide an accurate barometer of where Chicago's inconsistent offense ranks.
The only team that has been stingier than New England in allowing points is the Bears, and the Patriots are also No. 2 in rushing yards allowed and No. 4 in total yards allowed.
As much as the Bears want to demonstrate to every opponent that they can run the ball whenever they want, it's unlikely to happen against the Patriots. Thomas Jones has rushed for more than 100 yards in four of the Bears' past seven games and 98 yards in another. But the Pats have allowed just one 100-yard rusher all season, and that was nine weeks ago, when the Broncos' Tatum Bell picked up 123. Only three of 10 opponents have managed over 75 rushing yards against the Patriots.
The Bears rushed for a season-best 173 yards against the Jets' 3-4 defense last week, but the Patriots' 3-4 is similar to the Jets' only in name.
"They both play the same defense, but they have (17-year veteran inside linebacker) Junior Seau, and they have a lot of guys like that big (325-pound nose tackle) Vince Wilfork in the middle, (310-pound defensive end) Richard Seymour, (linebackers) Tedy Bruschi and Mike Vrabel," Bears guard Roberto Garza said. "You're talking about guys who are all great players and really make that defense work. They've played exceptionally well this year. In past years they've really put their stamp on stopping the run, and it's going to be a challenge for us on Sunday."
The challenge could be for the Bears passing game to carry the burden of moving the ball. That might be a problem for an aerial attack that generated a season-low 111 yards last week and has been held under 200 yards in four of the past six games. The league average is 206.5.
"I think every week we try to be a balanced team," quarterback Rex Grossman said. "We can run the ball. I think we've proved that the last couple of weeks. The passing game has been off and on the past couple of weeks, and we need to make sure that's part of it, too. It will (make us) a balanced team if we get back on track throwing the ball, and I'm looking at myself in that aspect."
Patriots coach Bill Belichick, perhaps the pre-eminent defensive mind in the game, will have something special prepared just for Grossman and the Bears offense.
"It's always a challenge," Bears offensive coordinator Ron Turner said. "I've got so much respect for Bill Belichick. What they've done there is unbelievable. It's a challenge, no question about it, but it's also fun. We'll see what we can do."
But scheme explains just a portion of the Patriots' success.
"They don't really confuse offenses," center Olin Kreutz said. "They come out and they play, and they say they're better than you are, and most times they are. So we have a big challenge ahead of us, especially our front five because they have a real good front seven, so we have to see what we can do against them."