The Philadelphia Eagles will spend $15.5 million in cap space on the quarterback position in 2018. (Patrick Semansky/AP)

The stock of Philadelphia Eagles quarterback Nick Foles is at an all-time high coming out of Super Bowl LII. A backup for much of the season, Foles was called into action after starter Carson Wentz suffered a season-ending knee injury in Week 14, putting Foles under center — and in the hot seat — for a title contender. After a rough patch to end the regular season, Foles shined when it mattered most, completing 77 of 106 passes (72.6 percent) in the Eagles’ three postseason games, the highest completion rate ever in the playoffs among quarterbacks with at least 100 passes attempted in a single postseason, for 971 yards, six touchdowns and an interception. He was also named the Super Bowl MVP.

When asked directly whether there would be a competition between Foles and Wentz at the start of training camp next year, Philadelphia Coach Doug Pederson avoided answering the question, saying the team was “just going to enjoy this moment.”

Philadelphia should also enjoy having Foles on its roster in 2018. The 29-year-old passer is under contract with the Eagles in 2018 for the cost of just $7.6 million, according to Spotrac, making him either a cost-effective backup while Wentz recovers from his injury or an appealing asset who will draw significant interest on the trade market.

The former puts the Eagles in a much better position to contend for another championship next year.

Keeping the championship window open for an extended period of time is not easy. Since the NFL expanded to 32 teams in 2002, just six franchises — the New England Patriots, Pittsburgh Steelers, Seattle Seahawks, Indianapolis Colts, Denver Broncos and New York Giants — have made a second Super Bowl appearance within five years. It took the Carolina Panthers (12 years) and Eagles (13) more than a decade to get another chance at a championship ring. Nine other teams got just one bite at the apple, illustrating if you have the ingredients of a championship-caliber team, it is best to keep them together as long as possible.

Just ask Seattle. The Seahawks appeared in back-to-back Super Bowls in the 2013 and 2014 seasons, with quarterback Russell Wilson taking up less than $1 million in cap space on his entry-level deal, looking every bit a perennial contender. Then Wilson signed a four-year, $87.6 million extension in 2015, leaving the Seahawks with fewer resources to build the team around him. The Eagles have Wentz, an MVP candidate before his injury, on his entry-level deal until 2019, which carries a cap hit of $7.3 million next season. That allows the Eagles to use just $15.5 million in cap space on the quarterback position in 2018, the 19th-highest amount in the league heading into free agency — a huge advantage for a Super Bowl contender.

In addition, a rash of quarterback injuries in 2017 underscored the importance of having a capable backup. The average starter posted a passer rating of 86.5 last season, while backups managed a mere 63.5 passer rating. That, in turn, was the difference between teams scoring 2.6 more points than expected per game based on the down, distance and field position of each throw compared to 4.5 points fewer per game from the backups — a swing of more than a touchdown.

2017 Passer rating Expected points added per game via the pass
Starting quarterbacks 86.5 plus-2.6
Backup quarterbacks 63.5 minus-4.5

The difference between those performances is huge. A passer with a rating of 86.5 producing 2.6 extra points per game can be found on teams with an average win-loss record of 8-8. A passer with marks of 63.5 and minus-4.5 is found on teams going 5-11, a three-win difference during the regular season. Foles’s numbers during the regular season were pedestrian, but his postseason performance was sensational, proving that Pederson can make the adjustments needed to keep his quarterback — whether that is Foles or Wentz — productive.

2017 Passer rating Expected points added per game via the pass
Regular season 81.4 minus-7.4
Playoffs 118.6 plus-20.0

Obviously, not all of the added value is produced by the quarterback alone — the offensive line needs to protect the pocket, receivers need to make plays, etc. — but based on the data going back to 2011, the first year under the current collective bargaining agreement, we can attribute about 45 percent of the added value to the quarterback, making the difference between an average starter and backup worth 1.4 wins during a 16-game season. Based on what NFL teams must pay replacement-level players (approximately $1 million per player, including rookies), the amount a team spends above and beyond those minimum contracts for a 53-man roster ($125 million), and the number of wins it takes to go from replacement-level to league average (eight), each win above replacement a player can contribute to a team is worth approximately $15.6 million. If we agree Foles is an average starter — not a backup — then his value to the Eagles is worth $21.8 million in 2018, for which they will pay him $7.6 million.

Plus, the Eagles are also in a unique situation — they have a top-flight defense that held opponents to 1.5 points per drive during the regular season and playoffs combined, the fifth-best mark in the NFL last season, which means their offense doesn’t need to fire on all cylinders all the time to win games. In fact, 22 of the league’s 32 teams posted at least 1.6 points per offensive drive in 2017, giving those squads a good chance of pulling out a win, reducing the risk of any quarterback under center.

I’m not really worried about my future right now,” Foles told reporters Monday morning at a news conference. “I’m grateful to be a part of the Philadelphia Eagles. I said when I signed with the Eagles: I’m grateful and content in this moment. Well, I’m staying in the moment. I’m not worried about my future right now.”

If the Eagles are smart they will realize the future is now, and Foles should be kept around for at least one more year.

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