Pats' flawed defense ill-equipped to carry Cassel

In Week 14 of the 2006 season, the Dolphins surprised the Patriots with a 21-0 thrashing. Over the next 21 regular-season games, the Patriots never lost, while the Dolphins won only once.

Even with the injury to Tom Brady, it was hard to imagine Miami traveling to New England and pounding the Patriots 38-13, as it did Sunday. The wholesale domination showed the Patriots' problems might go beyond Brady's absence.

Brady's replacement, Matt Cassel, played poorly, but it is expected the Patriots' offense will struggle at times with an unproven signal-caller. Through two weeks, however, it seemed the Patriots still could win 10 games and reach the playoffs with good defense and solid game management.

Miami's 0-2 start, meanwhile, appeared to show last season's 1-15 team still was very much in the rebuilding stage. What changed Sunday?

The biggest headline from this game obviously was Ronnie Brown's impressive five touchdown (four running, one passing) performance. Four of Brown's five touchdowns came on plays in which he lined up as the quarterback, a formation that flummoxed the Patriots throughout. The Dolphins can show this gimmick from time to time, but other teams will not be so ill prepared.

Those clever formations were not the only way Miami moved the ball. The Dolphins also ran the ball well in traditional formations. Ricky Williams, all but useless the first two games, totaled 98 yards on 16 carries. The Dolphins were able to dominate the interior line of scrimmage. Patriots nose tackle Vince Wilfork was a complete non-factor, as Miami center Samson Satele controlled the point of attack. The second-year player is definitely an intriguing talent for a team that is searching for difference-makers.

Wilfork's struggles were symptomatic of a team-wide inability to attack the line of scrimmage. The Dolphins' misdirection plays left defenders on their heels. The Patriots' older, bigger linebackers were unable to get going once they paused, and Brown and Williams easily slid through the resulting holes.

The struggles at the point of attack were not news for the Patriots. Football Outsiders measures the success of offensive and defensive lines with our Adjusted Line Yards stats (explained here). Through Week 9 of the 2007 season, the Patriots' defensive line ranked 13th in the league. Over the past eight weeks, it has ranked a woeful 27th.

If the running game were the only problem, the Patriots could toy with using safeties in run support. The snag is that the Patriots were equally undone by the Dolphins' passing offense. Until Brown's passing touchdown that put the Dolphins up 28-6 and effectively ended the game, the Dolphins were passing on 50 percent of their plays. Chad Pennington efficiently diced up the Patriots' zone coverage. The Patriots often play zone and try to disguise schemes. The departure of cornerback Asante Samuel leaves them thin in the secondary and even less likely to play man-to-man.

Pennington's lack of arm strength makes man coverage the preferred option, but the Patriots were stuck in zone. Pennington responded by dominating the middle of the field for 10- to 20-yard gains against the Patriots' linebackers. He completed 16 of his final 17 passes and was never sacked. He, as much as Brown, controlled the game.

Miami's anemic offensive performance in its first two games means Sunday's win could have been an aberration. An improving line, an increased role for Brown and heady quarterback play at least provide some foundation for future improvement.

The bigger story here is in New England, where the defense might not be ready to carry the Brady-less offense into the playoffs. To earn a sixth straight playoff berth, the Patriots need Cassel to develop to the point at which he can be relied on to do more than just not make mistakes.

Ned Macey writes for FootballOutsiders.com