WE THOUGHT they might save us.

It fueled our rosiest hopes, even conned us a little when the Eagles won their first three games of the season. Defense was going to keep them in games, win a few even that they had no business winning, allow Carson Wentz to learn from his mistakes. The front four was going to be our Clearasil, reducing and eliminating the blemishes that scarred the three seasons under Billy Davis, allowing the usual suspects on the back end to escape mostly unscathed.

Instead, the Eagles stand at 5-8, one game worse than their record at this point last season, a season that cost their previous head coach and previous defensive coordinator their jobs. "I never thought this season would go the way it has," Bennie Logan was saying at his locker Wednesday afternoon. "Especially in that we worked so hard in the offseason. You probably hear that over and over . . . But it's definitely a hard thing to handle."

"There's a bunch of stuff that we pride ourselves on that we didn't get done," said Brandon Graham. "One play here, one play there that kind of cost us in those games."

Which begs this question, as the Eagles play out another string of meaningless December games: Which defense is more disappointing, the one that ended last season under beleaguered Billy Davis, or the one that will end this one under the more-touted Jim Schwartz?

Statistically, there's no comparison between this season's Eagles defense and last year's. Under Schwartz, the current Eagles defense ranks 12th overall. In three seasons under Chip Kelly, Davis' defense ranked no better than 28th and last season it was 30th.

But even the harshest Davis critic would concede the merits of the alternative narrative. That Kelly pretty much mocked the importance of possession time, even as he found the NFL to be a much harder place to roll up points than it was in the Pac-12. Or to grab a prohibitive lead and force your foes to play catch-up. And that because of that, Davis' defense spent an inordinate amount of time on the field, and his efforts to keep down both opponents points and his own team's injuries were severely undermined.

For all its limitations and impotence of late, this season's Eagles offense leads the NFL in possession time. While this could be used as fodder to support Kelly's disregard of TOP, remember that he had the comparative luxury, especially that first season, of established linemen blocking in front of the likes of Michael Vick, Nick Foles and Sam Bradford, players like Evan Mathis, Jason Peters, Jason Kelce and, of course, Lane Johnson; that he had, for some of the time anyway, Pro Bowl caliber running backs (LeSean McCoy, DeMarco Murray) and Pro Bowl caliber receivers (DeSean Jackson, Jeremy Maclin).

It's intriguing, in fact, to imagine what last year's team might have done with Doug Pederson's more traditional-styled offense.

And that leads us back to Schwartz. His defensive schemes and philosophies were expected to launch Fletcher Cox into the next level. No such takeoff has occurred. Cox, in fact, notched his first sack after an eight-game drought Sunday against Washington.

Schwartz's defense was also expected to exploit the strengths of Logan, of Vinny Curry, of Graham. The ability to pressure quarterbacks with just four players would hide deficiencies in the secondary, or so was the thought. But as they did under Davis, the Eagles defense has allowed more passing plays of 20 yards or more (50) than all but one team.

"Teams have just been adjusting to the way we play since the beginning of the year," said Logan. "Back then, it was five-man protection against us. But once we showed we could rush the passer and get after the quarterback they haven't allowed us to do that. They've been getting the ball out quick. There has been a lot of six-, seven-man protection and things like that . . .

"And once one team had success . . . "

It started to look more and more like 2015. And questions about effort and energy, not sacks and turnovers, dominated the conversation as it had the year before. The effects of singular defensive mistakes, and not just on the back end, were toxic. Two third-down penalties on Cox - unnecceary roughness and roughing-the-passer - flipped potential victories in Detroit and Washington into defeats. Graham fed a Green Bay drive when he jumped offsides on third down. In the same game, Cox had yet another roughing-the-passer penalty on third down that kept a Packers' scoring drive alive.

These were the same kind of mistakes that sunk Davis, evoked questions about accountability - which Schwartz was hired to fix. "I know," said Graham. "Trust me, I know. But I think we have the right coordinator."

That would mean only one thing, he was told. That this defense needs more than a new coordinator and new scheme to save this team in the future.

"I'm not the one to judge that," said Graham. "Howie (Roseman) and those guys will figure out all that."

donnels@phillynews.com

@samdonnellon