Film review: The maturation of Nick Foles

One of the difficult things about evaluating Chip Kelly's NFL quarterbacks is that we have no baseline for comparison. With Andy Reid, we knew what the offense looked like when things were clicking, so it was obvious what wasn't working when they weren't.

Coming in to this season, we understood how Chip Kelly's offense looked at Oregon – thanks to the analysis of Grantland's Chris Brown and the team at Fishduck.com – but we had little idea how those same concepts would translate to the NFL. Especially because Kelly spent the whole summer tap-dancing around those questions every time a reporter raised them.

The preseason games helped a little, but throughout those contests Mike Vick and Nick Foles often looked like they were running two different passing offenses. Foles orchestrated a wide variety of quick screens and packaged plays, while Vick operated much more like a normal NFL quarterback – dropping back, scanning the field and finding open receivers.

Many people argued that Foles was the one who was really running "Chip's offense." But the one thing the pro-Foles crowd never explained – nor, really, could they – was if Foles was doing such a great job running the offense Kelly wanted, why wasn't he named the starting QB?

This same weird split continued into the regular season. Vick: normal passing game, lots of deep balls. Foles: Tons of screens, even more deep balls.

In Foles' first start against Tampa Bay, one-third of his pass attempts never crossed the line of scrimmage. Against Oakland, it was almost the same percentage. However, as noted in a previous post, these short throws were fantastically successful, gaining yardage well in excess of what we'd expect to see based on historical averages.

Oakland was also the game where we started to see "bombs away" Foles, as one-quarter of his attempts travelled more than 20 yards through the air before reaching a receiver. (The league average there is closer to one in nine.) These deep passes were also incredibly successful, accounting for half of his 406 yards passing on just seven throws.

At that point in time, there was reason to question the incredible statistics Foles had amassed (and not just because he sandwiched those two great games around a stinker in Dallas). It looked like Kelly was still running a separate Foles offense – one that only asked the quarterback to make definitive pre-snap reads, mixed together lots of easy throws short and deep, and wasn't likely to continue generating such outlandish returns once opponents knew what was coming and every lucky bounce stopped going our way.

But then we got to Sunday. Washington made it clear from the beginning they thought they could stop the Eagles by jamming the box and forcing Foles to beat them:

That's just what Nick did. And in the process, he completed his evolution from a two-trick pony into an NFL quarterback:

Les Bowen wrote earlier this week that we won't really know if Kelly is satisfied with Foles until the coach makes the affirmative decision to keep him and not bring in someone else. That's still true. But with Foles expanding his repertoire into the difficult intermediate passing game – successfully – there's no longer much chance I'm betting against him.

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Having said all that … let's take a look at that ugly Foles scramble near the goal line on the play after LeSean McCoy injured his hamstring. It's going to start like the inside zone we've seen so many times this year:

The linemen will try to block everyone to their right (left in this reverse angle) creating a "wall" for the running back. Washington safety Reed Doughty (#37) will drop out of the box just before the snap. Foles will be reading defensive end Brian Orakpo (#98). If Orakpo stays outside, Foles will hand off. If he crashes on the running back, Foles will keep it.

Fast-forwarding a bit, that's just what he does:

What confused lots of people is what happened next. After Chris Polk didn't get the handoff, he peeled into the flat in front of Foles, like he was setting up for some sort of shovel pass:

But look at center Jason Kelce in the middle of the field. He's six yards off the line of scrimmage, clearly blocking for a run play. If this had been a run-pass option, he would never have been this far downfield as an ineligible player.

Nick Foles may be the highest-rated passer in the NFL, but on this one our man was just slow.

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The Brent Celek near-touchdown at the start of the second quarter demonstrated in thunderous fashion something we've seen all year on Kelly's screen passes. At the moment Celek catches the ball, he'll have four big bodies in front of him:

Unfortunately, Washington defensive end Stephen Bowen (#72) is in position to tackle him from behind:

For a moment:

That blur is Todd Herremans, one of the front four, peeling back to block pursuers. And it's something we now see on almost every running back or tight end screen. One of the linemen comes back to pick up the chase defenders.

Here's a screen to Bryce Brown on the next drive. This time, there are three in front:

But left guard Evan Mathis is going to turn back inside and pick off whichever trailing defender seems most dangerous:

This is not something I remember seeing from Andy Reid's offense and it helps explain why the screen game has been so effective this year.

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On the defensive side, rookie nose tackle Bennie Logan made a play in the second quarter that illustrates both how athletic the 309-pounder is and what some of the Washington players meant when they said the Eagles were very well prepared for this game.

Starting just before the snap, check out the alignment of the Eagles on this first-and-10 play:

Both Logan (#96 in the middle) and Cedric Thornton (#72 to his left) are flexed well off the ball. They look to be running some sort of "game" inside at the snap, as defensive coordinator Billy Davis has taken to doing the last few weeks, rather than just having his three down linemen sit there like ducks each play.

From there it's just Logan tracking the play like he was shot out of a cannon:

Both Connor Barwin and Cary Williams are doing their jobs on the outside to force the run inside where Logan can make a play. If he hadn't, this is blocked up pretty well and Morris might still be running.

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As a final note, let's talk about Chip Kelly's policy towards challenging bad calls. He's gotten a lot of criticism the last two weeks for plays where opponents clearly had one foot out of bounds, but he didn't throw the challenge flag in time for a review.

There's no defending the Jarrett Boykin (non-)catch. That was a huge play at a critical time and Kelly definitely should have asked the officials to take another look.

Last Sunday, Alfred Morris stepped out of bounds after gaining one yard on a second-quarter run. The officials didn't see it and awarded him eight more yards before he was finally brought down. He clearly stepped on the chalk, but Kelly might have been right not to challenge that call even if he knew he'd get it overturned.

For this analysis, we can turn to the work done by Brian Burke of Advanced NFL Stats. He has a database of hundreds of thousands of past NFL plays, which allows him to calculate the expected swing in the final outcome of a game based on any play that takes place.

Using his win probability calculator, we can punch in the relevant numbers from the Morris run to determine that if he had been stopped after one yard, the Eagles' win chances would have been 73 percent. With the longer, ill-gotten gain, their probability dropped to 71 percent.

Maybe a two percent change is worth a challenge later in the game, but remember the NFL's screwy replay system. Coaches that don't get their first two challenges right don't get a third opportunity to throw the red flag. And we've seen that inability to challenge a bad call late become a huge factor in games before.

Kelly is as tight-lipped on his challenge policy as he is on what's in the smoothies, but if he's saving his challenges – like his timeouts – for when he really needs them, we should probably stop freaking out every time some minor oversight goes against our guys.

Derek Sarley can be reached @igglesblog. His work can also be seen at www.igglesblog.com.