Video analysis: Why the Eagles can't run
In the second quarter of Sunday's game against Washington, the Eagles tried to run the ball against the most favorable pre-snap look they've gotten all year:
The defense is showing two safeties, each almost 15 yards downfield. Only five defenders are in the box facing five blockers. Both slot defenders are shading inside, but no one is close enough to plug that gap off the right shoulder of center Jason Kelce.
For reasons I don't understand, the Eagles don't fire straight off the ball here, sticking double teams on the defensive tackles, since there's no one at the second level they could come off and block anyway. Instead, they run zone right, and that's where the trouble starts:
Post-snap, Kelce and Washington's Chris Baker do a dance we've seen a lot this year, with Baker slanting hard inside, right through the patch of grass Kelce just vacated as he tried to work his way around him. That turns what looked like an easy ten-yard gain into a five-yard loss.
Many explanations have been offered for why the Eagles are struggling to run the football, from a lack of offensive line talent to predictable schemes to injuries. But this conversation has so far been overly focused on this season, when the truth is that the Eagles' run game hasn't been special for much longer than that:
In Chip Kelly's first season, the Eagles averaged 5.2 yards per rush. Last year, they fell to a league-average 4.2 YPC, even with the addition of the explosive Darren Sproles. So far this year they're at pi, with an anemic average gain of 3.14 yards per rush.
In an attempt to understand what's changed, I called up the coaches film from 2013 for the week 11 game against Washington. I expected to see an Eagles offensive line operating in sync and opening holes for a well-oiled rushing attack. What I actually saw was a whole lot of this:
And this:
According to the game charters at Football Outsiders, LeSean McCoy was second in the league with 51 broken tackles in 2013. It's not clear how many of those were deep-in-the-backfield disapparations like the two examples we just saw, but it's fair to say DeMarco Murray isn't the first Chip Kelly running back to receive handoffs and tacklers at approximately the same time.
McCoy's ability to turn less-than-nothing into something was one reason the Eagles have been such a boom/bust rushing team under Kelly. Turning again to the numbers, the McCoy-led attack in 2013 was first in second-level yards (5-10 yard carries) and second in open field yards (>10 yard carries), but only 25th in "adjusted line yards," which purports to be a measure of offensive line effectiveness and goes down when running backs are frequently stuffed. All those ranks dropped in 2014 (6th, 9th, 29th), but the same pattern emerges.
You probably don't want to look at the 2015 ranks.
This is an unusual pattern. League wide, there's a strong correlation (0.69) between a team's adjusted line yards and the actual yards its running backs gained. In Kelly's first two years, the Eagles have been very outlier-y (green dots):
Time marches on. McCoy was pretty dinged up last year and might not play again this season until week nine. Even had they kept him, the Eagles weren't getting the same Shady who dazzled the league two years ago.
For one season, however, he was special. And he was special in a way that could cover up a lot of the same issues we're treating as new problems now.
This summer, in a closed media session for the beat reporters, Chip Kelly explained his theory of change: "I was probably a pain in the [butt] as a little kid because I questioned everything … There's a Latin term, mutatis mutandis, which is, 'If there's a reason for [change], then do it.'"
Kelly didn't get that Latin bit quite right. The term actually translates as "with necessary changes being made" and is a caution against assuming we can just change one variable and expect the rest to hold constant (aka ceteris paribus).
To one school of thought, the Eagles offense struggled last year due to an inability to sustain drives by stringing together shorter chunks of positive yardage. The solution, replacing a "jingle-footed" home run hitter with a couple of blue-collar runners and swapping out a gunslinger for a chain mover at the quarterback position, made perfect sense – as long as you assume everything else would stay the same. Except it never does.
On changing the status quo, the English writer GK Chesterton told a story: "There exists … a fence or gate erected across a road. The more modern type of reformer goes gaily up to it and says, 'I don't see the use of this; let us clear it away.' To which the more intelligent type of reformer will do well to answer: 'If you don't see the use of it, I certainly won't let you clear it away. Go away and think. Then, when you can come back and tell me that you do see the use of it, I may allow you to destroy it.'"
In the Chip Kelly narrative, his perpetual willingness to question the conventional wisdom is always presented as a positive. The problem for the Eagles is that with the demotion of Howie Roseman, there's no one left to defend the conventional wisdom when it's actually right.