Brady's absence doesn't hide Patriots' defensive woes

The Patriots' defense has struggled to stop opponents this season, giving up nearly 22 points per game. Cary Edmondson/US Presswire

If Tom Brady had not torn the ACL and MCL in his left knee early in New England's opening game, would the Patriots be 3-2, with both losses by margins of 20 or more points? The transfer of power from Brady to untested backup Matt Cassel certainly has not come without its struggles. But teams before the 2008 Patriots have survived the loss of a franchise quarterback.

The 1972 Dolphins, whose undefeated season the 2007 Pats almost trumped, lost starter Bob Griese to a broken leg in the fifth game of the season. Veteran Earl Morrall stepped in under center until Griese returned in the AFC Championship Game, and the Fins didn't miss a beat. Of course, Miami also had the No-Name Defense, Hall of Fame talent throughout its offensive line and the best rushing attack in the game.

And that's what's worrisome about the 2008 Pats. You knew they were going to lose traction without the reigning MVP, but even a healthy Brady wasn't going to be on the field to help a defense that gave up five touchdowns to the upstart Dolphins and their single-wing trickery. Nor would Brady have been able to contribute to a pass rush that Chargers quarterback Philip Rivers sailed through as San Diego wailed on New England 30-10 Sunday night. As much as Cassel hasn't been the solution, other problems have been exposed. Using Football Outsiders' proprietary stats, let's find out where the leaks have been springing. (You can find an explanation of these statshere.)

New England's running game hasn't intimidated anyone since Corey Dillon gained 1,635 yards in 2004. When its offense was going like a greased rocket, that wasn't a problem -- multiple passing options and wide formations forced defenses out of line-stacking attacks.

With a more pedestrian passing game, the Patriots now need a consistent, sometimes dominant, ground game to stay on top of the league. Right now, they're not even close. In 2007, Laurence Maroney ranked seventh in defense-adjusted value over average (DYAR), the FO stat that measures cumulative player value over the course of a season. Through six weeks in 2008, the top Patriots back in DYAR terms is Sammy Morris, and he ranks 28th.

Because New England has been unable to maintain consistency on the ground or in the air, its drive success has plummeted. The 2007 Pats ranked No. 1 in yards per drive, points per drive and touchdowns per drive, while amassing the NFL's fewest punts and turnovers per drive. In 2008, they've been positively ordinary, rounding out at about league average in those important numbers. Would Brady improve those numbers? Drastically, to be sure, because his mere presence would alter every defensive game plan. Brady or not, the real problem comes on the other side of the ball, where a formerly great defense is getting burned with alarming frequency.

We'll include the pass rush here, because it's the rare secondary that can keep up with receivers over and over without a consistent pass rush. New England has been unable to generate any heat on opposing quarterbacks, and losing Asante Samuel to the Eagles in the offseason left the team with Ellis Hobbs and Deltha O'Neal as the primary cornerbacks. Through the first three games (four weeks with a bye), our game-charting shows that O'Neal has been targeted 11 times by opposing quarterbacks, Hobbs 16 times.

Of those 11 attempts, O'Neal has allowed six completions with only one of five incompletions defended. Hobbs allowed eight completions, but of his eight incompletions, only three were defended or intercepted. The rest in both cases were overthrown or dropped. In Philadelphia, Samuel was targeted 18 times through four games, with nine completions and six of nine incompletions listed as defended. New England's current secondary will find Denver's highly productive passing game to be a challenge Monday night.

That precipitous drop in sacks is a bad sign against a Denver offensive line currently ranked second in offensive adjusted line yards and adjusted sack rate. The New England front seven was worn out by Miami's Wildcat formation, and the Patriots displayed a worrisome lack of defensive speed. These trends cannot continue if New England hopes to make any impact this season.

How are the Patriots still special? Special teams and starting drive location. New England currently ranks second in special teams DVOA, and a primary factor in that ranking is that their average drive starts just past their own 33-yard line, fourth in the league. Unfortunately, that advantage serves to highlight the Patriots' relative offensive inefficiency. Ranking 25th in points with 89 and scoring eight touchdowns all year (this, by the way, ties them with the Detroit Lions, near the bottom of the ladder), doesn't feed the bulldog. Giving up 13 touchdowns and 109 points? Well, that's further evidence that although Brady's absence has exposed a multitude of on-field sins, a declining defense is just as much to blame for a frustrating start to the 2008 season.

Doug Farrar is an analyst for Football Outsiders.