The Philadelphia Eagles, and their fans, are embracing their status as the biggest Super Bowl underdogs since 2009. The WestGate SuperBook in Las Vegas has the New England Patriots as 5.5-point favorites in Super Bowl LII and, according to William Hill Sports Book in Nevada, more than three-fourths of the money was being bet on New England as of the morning of Jan. 23.

Historically, this is a terrible position to be in. Among the 26 Super Bowl teams that were at least five-point underdogs, just five ended up with a championship ring. To be fair, Philadelphia, the No. 1 seed in the NFC, was a historic underdog in the divisional game and a three-point underdog against the Minnesota Vikings in the NFC championship game, both ending in victories for the Eagles.

If they are to pull off another big upset against the Patriots the biggest key will be to control the line of scrimmage.

On offense that means leaning on an offensive line that ranked eighth during the regular season according to Pro Football Focus’s Pass Blocking Efficiency rating, a metric that measures pressure allowed on a per-snap basis with weighting toward sacks allowed. All-pro offensive tackle Lane Johnson, all-pro center Jason Kelce, Pro Bowl guard Brandon Brooks, Stefen Wisniewski and Halapoulivaati Vaitai were not held responsible for the sack against Foles in the NFC championship game by the game charters at Pro Football Focus and were instrumental in keeping Foles clean in the pocket against one of the NFL’s best defenses. Their quarterback responded by going 19-for-23 for 213 yards and a touchdown when there was no pressure. Foles repaid the favor by putting up a robust 7-for-10 performance for 139 yards and two touchdowns in the face of the Vikings’ pass rush. That’s a huge difference from the regular season, where Foles had a 23.8 passer rating under pressure. An incomplete pass, by comparison, produces a passer rating of 39.6.

New England’s pass rush is no where near as prolific as Minnesota’s: PFF has the Vikings ranked 12th in 2017 while the Patriots rank last.

Nick Foles … 2017 regular season vs. Vikings in NFC championship game
Facing no pressure 107.8 119.7
Under pressure 23.8 152.1

If the line can keep pressure away from Foles, the Eagles should be able to move the ball against the Patriots, which was not that difficult this season.

New England allowed 5.9 plays per drive, the second-most in 2017, with a league-high 34.2 yards allowed per drive. It was, however, a bend-but-don’t-break defense, allowing a red-zone conversion rate of just 44 percent, the fourth-best mark during the regular season. Philadelphia’s running backs could change that.

The team led the league in red-zone efficiency during the regular season (66 percent) and behind Jay Ajayi and LeGarrette Blount, Philadelphia’s rushing offense averaged 132.2 yards and scored nine touchdowns, giving the Eagles a slight advantage when it comes to gaining yardage — New England’s rushing defense yielded 114.8 yards per game and stopped just 16 percent of rushers at or behind the line of scrimmage. Only the Washington Redskins (15 percent) and Chicago Bears (14 percent) were worse in 2017.

Blount, meanwhile, led the league in yards per carry after contact (3.6) and Ajayi had 12 rushes of 15 or more yards, good for 10th most at the position.

Running the ball effectively also allows Philadelphia to control the clock and keep the Patriots offense off the field, another ingredient in the recipe for success against New England. But when they do have to face Tom Brady, Philadelphia has the pass rush to disrupt his rhythm, and that’s not easy to do.

During the regular season Brady led the league in passer rating under pressure (96.6, 12.7 points better than Jameis Winston, who was second), but that’s still better than giving him a clean pocket (105.7). Philadelphia’s defensive coordinator Jim Schwartz doesn’t rely on extra blitzers to generate pass pressure. The Eagles blitzed Matt Ryan on just 8 out of 39 drop backs in the divisional game against the Atlanta Falcons and even less (7 out of 50) against Minnesota Vikings’ quarterback Case Keenum in the NFC championship game. The success stemmed from pass-rushers Brandon Graham, Chris Long, Vinny Curry and rookie Derek Barnett, who combined for 22 sacks this season and, according to PFF, are part of the most-talented pass-rushing unit in the NFL this season. Replicating that success against the Patriots will be essential to any upset bid.

Creating pressure with only four linemen allows safety Malcolm Jenkins and Rodney McLeod to remain in coverage, where they allowed 0.7 (39th out of 59 safeties) and 0.4 (15th) yards per coverage snap, respectively. Overall, Philadelphia’s secondary allowed a passer rating of 79.5 during the 2017 regular season and a league-leading 73.6 rating against in the playoffs.

Covering a 5.5-point spread is a significant feat. If the Eagles are to do it, it will start with the factors above. But if these keys align, it could end in a Super Bowl victory.

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