This season, Patriots quarterback Tom Brady basically has operated in a protective cocoon, his offensive line having surrendered just 13 sacks, the second fewest in the league. Three of those sacks, though, came in Week 12 against the Eagles, who drew closer than anyone else has to beating New England.
Philadelphia defensive coordinator Jim Johnson was typically masterful in varying his fronts, often using only three down linemen and three linebackers, and bringing pressure from up the middle. The Eagles didn't sell out to the rush as often as they have in past seasons, and they rarely rushed six defenders, but they did change up their rush angles and coverages deftly.
Is that a template the Baltimore Ravens will follow Monday night?
"I don't know; you'd have to talk to those teams," Patriots coach Bill Belichick told the New England media earlier this week. "I don't know what they're going to do. All I know is what we're going to try to do, and that's prepare for Baltimore, study them, get to know them. It's a team we haven't played in a while."
No one should expect defensive coordinator Rex Ryan and the Ravens, who reside in last place in the AFC North, to play many three-man fronts, but they are almost certain to unveil a few new wrinkles. Ranked just 15th in the league versus the pass, Baltimore seems particularly challenged by the prospect of facing the top-rated New England aerial circus.
The Ravens, who have lost five straight games for the first time since Art Modell relocated the franchise in 1996, aren't going to be able to salvage their season. But a veteran defense that features emotional players such as middle linebacker Ray Lewis, outside linebacker Bart Scott, cornerbacks Samari Rolle and Chris McAlister, and free safety Ed Reed would take some pleasure in upending the undefeated Patriots.
"Our guys are going to play fast, furious and with a lot of emotion," Ryan said. "We're coming with all we have, and if the Patriots are expecting less of a game from us, they're sadly mistaken. It's going to be a great challenge for us. But we're going to make sure that it's going to be a great challenge for them, too."
Not many people outside the Ravens' locker room expect the game to be close, though.
According to The Baltimore Sun, the Ravens are the biggest home underdogs in modern NFL history, with oddsmakers setting the national betting line between the teams at 20 points. Not since 1974, The Sun noted, has a 20-point underdog won a game outright.
"You read all their press clippings, and look at the big numbers they've put up, and it really is amazing," Rolle said. "They're on a roll, the likes of which hasn't been seen in this league in a long, long time. Maybe ever.
"I mean, everyone brings up how well Philadelphia played them last week. But, hey, the Patriots still hung 31 [points] on them. But you know what? We're professional football players here, too, and we think that we know how to play the game. We're not just going to roll over like dogs."
Although it's unlikely the Ravens have paid much attention to the betting line, they know that to become the first team in 2007 to defeat the powerful Patriots certainly will take the best effort of the season from their defensive line. And that probably will mean exerting the kind of pressure on the pocket that the Baltimore defense -- statistically the best in the NFL in 2006, when the Ravens were 13-3 -- brought in nearly every contest last year.
Such pass-rush heat has been lacking this season, however. Although Ryan hasn't changed the scheme, the results have been dramatically different. Baltimore posted 60 sacks in 2006, and seven players had at least three quarterback knockdowns apiece. Through the first 11 games of 2007, the Ravens have just 22 sacks, and right end Terrell Suggs, with four, is the lone defender with more than two sacks.
One can attribute some of the pass-rush deficiency to the injuries that knocked left end Trevor Pryce out of the lineup and eventually to season-ending injured reserve. And the Ravens lost Pro Bowl linebacker Adalius Thomas to the Patriots as an unrestricted free agent in the spring. The pair combined for two dozen sacks in 2006, and the Ravens have struggled to compensate for their absences.
Yet in the past, the creative Ryan -- son of legendary Buddy Ryan, who always believed you had to do whatever it took to hit the quarterback -- always has conjured up ways to produce pressure, even when he didn't have the best players. This season, however, the overload fronts and rush packages that brought blitzers from every angle imaginable haven't produced the kind of results to which the prideful Baltimore defense is accustomed. The team also has played from behind for much of 2007, allowing opponents to run the ball more and reducing Baltimore's pass-rush opportunities.
None of which will stop Ryan, or a Ravens' defense that still features six veterans who have played in at least one Pro Bowl, from trying to attack Brady.
Senior writer Len Pasquarelli covers the NFL for ESPN.com.