By Peter Gleason

The “underdog” Eagles were left as an afterthought when Carson Wentz went down in Week 14 with a torn ACL. Surely, even after clinching the No. 1 seed in the NFC, Nick Foles would be their undoing at some point.

Not in the NFC Championship game, where the QB dive-bombed a great Vikings defense for 352 yards, three touchdowns, and a 78.8 completion percentage.

Vikings safety Harrison Smith still sounded befuddled by the 38-7 blowout this week during Pro Bowlpractices.

“We didn’t make plays and they made pretty much all of them. I didn’t think that would happen,” Smith said.

In two playoff games Foles is averaging a 77.8 completion percentage, thrown for 598 yards, has taken just two sacks, and earned a 122.1 passer rating.

The reason for Foles’ success has been mostly attributed to a three-word offensive scheme: Run-Pass Option.

The RPO, which Smith referred to as a “trendy” offense, allows the quarterback the option to hand the ball off to the running backs or, if he reads the linebackers stepping up, pull the ball and zip it to a receiver. Doug Pederson’s use of RPOs has gotten Foles in rhythm and proved deadly for defenders. This season, including playoffs, Foles has completed 93.8 percent of his RPOs, per Pro Football Focus.

As Carolina Panthers linebacker Thomas Davis said this week, RPOs put defenders in a no-win situation when executed properly.

“It’s pretty much a play where you can’t be right as a linebacker,” Davis said after Pro Bowl practice. “Because if you guess and you play downhill to play the run they’re going to throw the ball right where you were. If you drop back and you play the pass, then they’re going to hand the ball off. So the quarterback is basically reading the linebackers and safeties in that situation and it’s a situation where a lot of the time you can’t be right.”

The key for the Eagles RPOs has been the steady play of running backs Jay Ajayi and LeGarrette Blount. If the threat to run isn’t real, it takes the bite out of any RPO action.

“Those guys are tough runners,” Smith said of the Eagles backs. “Both of them run extremely hard but they both have their own different style, so between Jay and LeGarrette they can do some damage.”

Couple the RPOs keeping defenders off balance with a dominating offensive line and you have the recipe for a successful offense, no matter who is under center. The Eagles underrated O-line deserves credit for moving bodies in the run game and keeping pressure off Foles.

“They have a very fast offensive line,” Vikings defensive tackle Linval Joseph said. “…And they’re very athletic, very strong at the attack. The center they have is a really good center. And 65 (Lane Johnson), they’re fast athletes, they run 4.8-4.7. So as you see, they can get around the edge and change their plays up. Act like it’s a screen and really it’s a run.”

Heading into the Super Bowl, that unpredictably will be key for Philly. The Eagles spread-out system, coupled with a power-back duo, could take advantage of the Patriots’ defensive weakness. We’ve seen similar offenses like the Kansas City Chiefs dice up Bill Belichick’s squad in the past. When it comes to defending RPOs, the Patriotsallowed 5.6 yards per play in 2017, fifth-most in the NFL, per PFF.

If Foles remains hot, the key for Philly will be slowing down Tom Brady and the Patriots offense.

Eagles defensive coordinator Jim Schwartz deploys a game-wrecking front four that ranked No. 1 in rush D this season. Being able to stop the run and get pressure on the quarterback with four defensive linemen allows the Eagles to flood the second level to take away quick crossers.

Vikings Pro Bowl receiver Adam Thielen said not to underestimate the Eagles secondary.

“They’re a secondary that doesn’t allow easy catches,” Thielen said. “That whole week on film you saw how there was contested catches. Every single catch was contested. They were all over people. I don’t think they get enough credit in the back end of how well those guys are playing… guys are all over the place and in the right spots.”

That opportunistic secondary plays off the quick pressure provided by the front four and Schwartz’s blitz schemes.

“I think they know that that front four is really good and they’re going to get pressure,” Thielen said of the Eagles secondary. “So they know they can be more aggressive and they can sit on routes and they can do things like that. They know how to play with each other. They’re very well coached. And their technique is some of the best out there.”

The coaching angle shouldn’t be oversold. While Bill Belichick is one of the greatest coaches in the history of all sports, the work Pederson, Schwartz, and the rest of the Eagles staff has done this season is worthy of this Super Bowl run. Despite all the injuries, the coaches found strengths of players who took over and accentuated those attributes.