From turnstile to versatile, Eagles defense changes image | Bob Ford

In the very first series of Sunday's game against the Denver Broncos, coordinator Jim Schwartz sent his defense onto the field and began an afternoon of designed mayhem intended to have the opposition swinging at ghosts and grasping at the shifting mists of its game plan.

Before the Broncos finished that series with a 52-yard field goal – it would be fair to say the lead didn't last long – the Eagles had played their base defense of three linebackers, had shifted to nickel coverage with an extra defensive back, had put four linebackers on the field for a 4-4 front, had blitzed from both sides of the field with both linebackers and defensive backs, had nearly forced an interception, had hit quarterback Brock Osweiler twice and, generally speaking, had announced their presence.

If the Denver offense already suspected the Eagles were going to make it a long day for their new starting quarterback and their mistake-prone offense, they had no idea how long. It wasn't just that the Broncos were unable to beat the Eagles physically — they were unable to dictate the scheme advantage that usually comes with being the side that is actually calling the plays.

"Everybody is dialed in," defensive end Brandon Graham said. "Everybody knows the game plan, and we execute. Everything is not perfect, but overall, everybody is striving to be perfect."

The defense isn't perfect by any means. It has allowed the fewest rushing yards in the league but remains susceptible against the pass at times. The Eagles are 12th in the league in points allowed per game. What is remarkable is that the defense has been as consistent despite losing starting cornerback Ronald Darby at the beginning of the season and, more recently, middle linebacker Jordan Hicks, and being without cornerback Jaylen Watkins for four games and star tackle Fletcher Cox for most of three games.

Schwartz has kept his foot on the accelerator despite having to mix and match his alignments, and he hasn't simplified the approach to account for the changing personnel. Against Denver, there were back-to-back plays at one point of the game in which the defense went seamlessly on one play from another 4-4 front to a dime package with six defensive backs on the next. He switched between Watkins and rookie Rasul Douglas as the nickel back throughout the game, and all these formations, all these adjustments, took place without last-second panic or a wasted timeout or, seemingly, anything but the smooth meshing of gears.

"It's his confidence in us because we've got to be able to grasp all those things," said safety Malcolm Jenkins, who often operates near the line of scrimmage like a mini-linebacker. "It's a nod to the amount of prep guys put into what we're doing. We have so many positions and packages, and we change it week in and week out. I've been around teams that couldn't do that. It gives you an advantage on anybody that wants to game-plan for us, or try to find matchups to take advantage of."

Against type, or what had presumed to be his typecasting, Schwartz has used blitzes more frequently this season. The blitzes haven't produced an amazing number of sacks – the Eagles are 16th in the NFL in sacks per passes defended – but have served to hurry the opponents into mistakes or shorter passes. Bringing additional pressure has also created an aggressive mind-set among the defense that adds to its own sense of identity.

"We want to give a whole bunch of different looks," linebacker Nigel Bradham said. "Everyone felt our defense is so simple. Coming into the year, you hear that a Schwartz defense is simple … not blitz much, play a lot of coverage defense. Then, you [play us] and you don't know what you're going to get. It says a lot about our players and our coaching that he trusts us to get that done. We give different looks every week, and they have to game-plan for them."

As the Eagles take a break at the bye with an 8-1 record, the most difficult stretch of the season for the defense is still to come. You can only play the schedule, but the one so far has been favorable for them.

"I think a healthy confidence is good, and we've done a lot of good work to get to this point," defensive end Chris Long said, "but we also need to take it to another level when we get back."

Thus far, the Eagles have played only one offense ranked in the top 10 in the league for yards per game or points per game, and that was their lone loss, to the Kansas City Chiefs. The eight wins came against Washington twice (14th, 14th), Arizona (15th, 26th), the L.A. Chargers (16th, T-22nd), Denver (17th, T-22nd), Carolina (21st, 24th), San Francisco (24th, 30th) and the N.Y. Giants (28th, T-28th).

Still to come are three road games against the L.A. Rams (3rd, 1st), Seattle (4th, 10th) and Dallas (8th, 4th), as well as a home game against the Cowboys. The defense should get Darby back after the bye, which will add to the depth, but the real tests of how good this unit can be are still to come.

"Getting into November, this is when games get bigger and bigger," Long said, "but we put ourselves in position to have big games."

They have earned every bit of it, whether with three defensive backs on the field or six, whether with one linebacker or four, whether with plugging the run gaps or blitzing the quarterback. The other team rarely knows what to expect, and whatever else changes between now and the end of that season, that seems likely to remain the same.