Late in the first quarter of last Thursday's game, the Lions chose their first entry into the red zone to run the play that defines the Eagles' season.

It was third and three. A tight end and two receivers were split to the right of the formation. The tight end went up the seam, while the middle receiver ran a quick out to screen Byron Maxwell and prevent him from following outside receiver Golden Tate as he came underneath on a short slant. With Maxwell out of the play and no help inside, the result was an easy third down conversion.

This first-down-via-refusal-to-jam-or-switch-receivers thing is a weekly feature of the Eagles' defense. We saw it four days earlier against Tampa Bay (with the added frisson of miscommunication between Maxwell and Mychal Kendricks). Miami did it too, only the tackling was even worse and it turned into a 43-yard gain.

If the Eagles were a basketball team, they'd be going under the screen every time Steph Curry ran the pick and roll.

Maxwell, the high-priced free agent acquisition, hasn't had a great season, but to understand some of what he's dealing with I'd like you to try an experiment tonight. First, stand next to a wall. Next, place a family member or housemate in the room that's on the other side of that wall. Then have a third participant toss them a football (or pillow or teddy bear) while you try to break up the pass.

1) Were you able to?

2) WHAT DO YOU MEAN A WALL WAS IN THE WAY DON'T WE PAY YOU TEN MILLION DOLLARS?

On both sides of the ball, there's a stubbornness to the Eagles' schemes that seems to be based more on preconceived notions of how football "should" be played and less on how they're actually going to beat the other team this week. It's the on-field manifestation of the same rigidity we see in personnel management and practice schedules.

Chip Kelly might call that same tendency "clarity of vision." And if the Eagles were 8-3 he'd have a lot more people agreeing with him.

NFL head coaches with offensive backgrounds choose defensive coordinators they themselves don't want to face. Andy Reid famously picked Jim Johnson after battling his aggressive blitzing schemes during his time with the Packers. As is his wont, Kelly has never explained why he favors the two-gap 3-4 base defense, but my guess has always been that he sees the zone-read-based spread as ascendant and thinks having three guys who can control four gaps is the best way to flip the math back into the defense's favor.

The Eagles' base scheme is inherently passive. The in-box defenders have to read the play first, then attack, which puts them at a disadvantage when pass rushing in ambiguous down and distance situations.

This would matter less if the team had a dominant edge rusher who could be counted on to provide one-man pressure. But despite the draft and free agent resources invested in that position, this remains the missing piece.

I think that may be why Davis has shown more "bear" fronts the past few weeks. That alignment puts the three defensive linemen next to each other across three interior offensive linemen, rather than spread out over the tackle-center-tackle. The advantage of this alignment is that you can almost guarantee one-on-one pass-rushing matchups inside for your defenders. The downside is exposing bigger off-tackle running lanes, if the offense can seal the three big bodies inside.

Both the defense and the offense have been atrocious on third down this year. Aaron Schatz of the advanced analytics site Football Outsiders reports that both units are 26th in third-down DVOA. The offense and defense are also 27th and 24th in raw third-down efficiency, respectively.

Of course, the offense has been pretty awful on first and second downs too.

It's also not your imagination – the defense has been particularly cataclysmic in third and long. Opposing quarterbacks have a 113.7 passer rating in third-and-10+ situations and their teams have converted those attempts 50 percent more often than the league as a whole.

There is a body of work, again by Football Outsiders, which has found that defenses that underperform their first and second down results on third down are likely to improve in the following season. That's partly due to offseason personnel changes to address those issues, but it's also a reflection of the higher variance and disproportionate impact of that smaller subset of third-down plays.

That's the stat head case, and it's compelling. On the other hand, when opposing offensive coordinators – every week – run the same scheme-breaking plays in high-leverage situations without much of an answer on our part, one wonders just how ceteris paribus those comparisons next year will be.