Patriots head list of NFL's top offenses

One of the main tenets at Football Outsiders states that offense is more consistent than defense. This is true between seasons, but it's also true during a season. So the best way for an NFL team to be taken seriously as a Super Bowl contender is to get off to a strong start on offense. That team is likely going to be winning games all year.

So after six weeks, we want to take a look at the best offenses in the NFL. Where are they strongest and weakest, and what has changed since last year? Offenses are ranked using our DVOA (defense-adjusted value over average) ratings, which score every single play's success based on down and distance then compares it to a baseline, adjusted for situation and opponent. The metric is described more here, and the 2015 numbers are here.

1. New England Patriots (32.8 percent above average)

Nothing really new to see here: The Patriots have ranked in the top seven in offensive DVOA for 11 straight years. Yes, that includes the Matt Cassel season. The Patriots were just sixth in 2014, but that's because of their slow start and the Week 17 game in which they sat Tom Brady. Between Week 5 and Week 16, they had the best offense in the league once again.

The biggest improvement in 2015 is the running game, thanks to the emergence of Dion Lewis and the full-season presence of LeGarrette Blount. The Patriots rank No. 1 in run offense DVOA. Obviously, part of this is that opponents are set up to stop Brady rather than the running backs, but strong play by the offensive line helps too. Patriots backs have been stuffed for a loss or no gain on a league-low 12 percent of plays; no other offense is below 16 percent, and the NFL average is 21 percent.

If the Patriots have a weakness, it's converting on third-and-long. That sounds like a strange statement because they lead the league converting 51 percent of third downs. But they convert so often because they're in good down-and-distance situations on so many third downs, with a league-low average of just 5.8 yards to go. The Patriots rank a surprising 24th in DVOA on third down with seven or more yards to go.

There is reason to worry about the blocking going forward. Left tackle Nate Solder was lost for the season with a torn biceps, and his backup, Marcus Cannon, also got hurt against Indianapolis last week. The Patriots have gotten away with starting two rookies, center David Andrews and right guard Tre' Jackson, but the defenses they face are about to get a lot harder. New England plays the toughest remaining schedule of defenses in the league, including four games against teams ranked in the top three of defensive DVOA (Denver 1, New York Jets 2 and Philadelphia 3).