New England Patriots tight end Rob Gronkowski helped the team score a league-high 2.6 points per drive in 2017. (Charles Krupa/Associated Press)

The NFL playoffs are set, giving us a chance to look over the field and separate the pretenders from the contenders.

Last year’s defending champions, the AFC’s top-seeded New England Patriots, will try to win back-to-back titles while enjoying home-field advantage throughout the playoffs, ensuring that any Super Bowl run from the conference runs through Gillette Stadium.

They appear to be a worthy favorite — the Westgate Las Vegas SuperBook has them at 2-to-1 odds — after scoring a league-high 2.6 points per drive behind an MVP-caliber season from quarterback Tom Brady, the third-most valuable passer in 2017 per ESPN’s Total Quarterback Rating.

However, there is at least one reason to doubt their chances of winning Coach Bill Belichick a sixth Super Bowl ring with the franchise: The Patriots have net passer rating differential of 13.1, the 10th-highest in the league this season.

Patriots Net passer rating Net passer rating rank Playoff result
2001 16.7 5th Won Super Bowl
2002 7.1 10th DNQ
2003 28.1 2nd Won Super Bowl
2004 17.2 5th Won Super Bowl
2005 3.7 14th Lost divisional round
2006 22.2 2nd Lost AFC conference championship
2007 37.9 1st Lost Super Bowl
2008 -0.7 16th DNQ
2009 13.9 10th Lost wild-card game
2010 28.6 2nd Lost divisional round
2011 19.6 4th Lost Super Bowl
2012 10.8 7th Lost AFC conference championship
2013 6.3 12th Lost AFC conference championship
2014 13.5 5th Won Super Bowl
2015 14.9 6th Lost AFC conference championship
2016 25.1 1st Won Super Bowl
2017 13.1 10th ?

Dubbed the “Mother of All Stats” during the 2012 Pro Football Researchers Association biennial meeting, net passer rating has been a litmus test for Super Bowl-caliber teams. Since 2002, 22 of the past 30 Super Bowl participants had a passer rating differential among the top five in the league, including 10 of the past 15 winners. The outliers among the eventual Super Bowl winners include the 2005 Pittsburgh Steelers (seventh), 2007 New York Giants (24th), 2011 Giants (12th), 2012 Baltimore Ravens (12th) and 2015 Denver Broncos (18th).

By this metric, the Minnesota Vikings look every bit a Super Bowl contender. Quarterback Case Keenum produced a passer rating of 98.3 in 14 starts (the team’s overall passer rating was 99.1) and played well enough to finish the regular season ranked No. 2 in QBR. The defense was led by defensive end Everson Griffen, who set a career high in sacks (13) and was ranked the 10th-best edge rusher per the game charters at Pro Football Focus. Minnesota’s secondary was also rated the fourth-best in pass coverage, resulting in the third-lowest passer rating against (73.0) in 2017. The result: a league-leading net passer rating differential of 26.1.

The New Orleans Saints were not far behind. Quarterback Drew Brees led the league in completion percentage (72 percent) and finished with a 103.9 passer rating. The defense improved significantly from the 2016 campaign, allowing just a 79.0 passer rating against in 2017, giving the Saints the league’s second-best net passer rating differential. The Los Angeles Rams, Kansas City Chiefs and Philadelphia Eagles round out the top five.

Aside from the Patriots, the Pittsburgh Steelers are also noticeably absent from the leader board. Quarterback Ben Roethlisberger posted a 93.4 passer rating and the defense had an above-average pass defense at 81.8 against, giving them a net passer rating differential of plus-12.3, the 12th-best in the NFL. But that does fall outside of the top 10, discounting their chances at a championship run.

Two playoff teams, the Tennessee Titans and Carolina Panthers, have negative passer rating differentials, making their title hopes a long shot, at best.

More on the NFL:

Niles Paul hopes Redskins give him another shot

Steinberg: The Redskins have an identity. It isn’t a good one.

After a disappointing year, Redskins enter another offseason of uncertainty

Brewer: Polarizing and unending Kirk Cousins debate gets fresh fuel with season finale stinker

Wings for everybody! The Bills are back in the playoff for the first time since 1999.

Bruce Arians retires and John Fox, Jim Caldwell are fired as NFL’s coaching carousel gains speed

The Raiders believe they will be able to hire Jon Gruden. But what about the Rooney Rule?

Marquise Goodwin’s season of tragedy and triumph ends with concussion

After firing Chuck Pagano, the Colts’ future is all about Andrew Luck’s shoulder