No matter the circumstance, Nick Foles could not be stopped in 2013.Following the Philadelphia Eagles' Week 8 loss to the New York Giants, the team fell to No. 26 in the weekly ESPN.com NFL Power Rankings and the Chip Kelly experiment appeared to be failing. Since then, Nick Foles and the offense have found their form, and the Eagles have ascended to 11th in the rankings.

How good is the Eagles offense though? And what changed?

The difference from the first half of the season to the second half for the Eagles’ offense is pretty stark, as the team averaged 11.5 points more per game over the last eight games of the season.

Eagles’ Offense This Season

The Eagles led the league in scoring from the start of Week 9 to the end of the season, committing the fewest turnovers during that stretch.

The Eagles’ offensive potency was due to a two-pronged attack, leading the NFL in average yards per rush and pass attempt this season. The last team to lead the league in both was the 2001 St. Louis Rams, who lost in the Super Bowl that season.

LeSean McCoy led the NFL in rushing this season, and actually gained more yards on the ground than 10 NFL teams, including the Eagles’ Wild Card opponent the New Orleans Saints.

The rushing offense saw a moderate jump over the second half of the season, going from 5.0 yards per rush to 5.3. The passing game saw the biggest increase. The Eagles averaged 9.9 yards per pass the last eight games of the season, a 2.2 yard increase.

Also helping matters was the pace of the offense. The Eagles averaged a play every 24.0 seconds of possession this season, the fastest pace in the last 13 seasons.

Foles didn’t make his season debut in Week 9 though, so what changed in Philadelphia that led to such a dramatic increase in offense?

For starters, the Eagles continued to add wrinkles to the offense, specifically play action off the zone read.

The Eagles used the zone read 304 times this season, 135 times more than the next highest team. The zone read offers a natural setup for play action, but the Eagles used a play fake on 24 percent of their passes the first eight games. Over the last eight games, that usage increased to 39 percent.

Eagles’ Play Action Passing
This Season

The Eagles’ play action passes were effective throughout the season, but adding more attempts and the more efficient Foles made the plays a staple of the offense.

Foles’ efficiency helped matters. Foles completed 64 percent of his passes this season with 27 touchdowns and two interceptions, the best touchdown-interception ratio in NFL history.

Michael Vick and Matt Barkley combined to complete 56 percent of their passes this season with five touchdowns and seven interceptions. Vick and Barkley played a combined 11 snaps from Week 9 and on, after recording 208 more snaps than Foles the first half of the season.