Sure, they've had good tackling cornerbacks before. Eric Allen loved being physical. Troy Vincent rarely missed a tackle. Sheldon Brown during his prime was as good as any cornerback in the league bringing down receivers.
But this? A secondary where every cornerback is a capable and willing tackler?
This is uncharted territory.
One of the reasons the Eagles go into the bye week 8-1 with a seven-game winning streak is the ability of this defense to prevent big plays. And that's all tackling.
By everybody. Not just the linebackers, safeties and guys up front.
Jalen Mills, Rasul Douglas, Patrick Robinson and Jaylen Watkins, the four guys who've gotten virtually all the cornerback reps this year, have all proven to be exceptional tacklers.
And it really sets the Eagles apart from other defenses.
"For me and for us, it's an absolute necessity, just like it is being able to cover and catch a ball or make an adjustment in the defense," secondary coach Cory Undlin said.
"I mean, if you can't tackle the way offenses are running the ball, especially this (Cowboys) team we're about to play, if you can't tackle on the perimeter, you're not going to be any good. We've committed to that just like we have with everything else as we go about our daily business.
"You've got to be able to tackle. You guys have seen it. … That is an absolute necessity. If you can't do that, you're not going to be out there. Just like if you can't cover somebody, you're not going to be out there."
The Eagles have allowed only 24 plays of 20 yards or more this year, and only four teams have allowed fewer per game.
But the numbers only say so much. You just watch these corners play, and you see how committed they are to being tough, versatile and physical.
“We’re very prideful in it," Mills said. "The whole defense tackles well, and we as corners don’t want to be the weak spot.
"You’re not going to knock down every pass or pick off every pass. That’s just the game. So when you don’t, you want to get those guys down as fast as possible. That 2nd-and-6, they complete a pass, stop 'em short of the (first down), and now it’s 3rd-and-1 and you give your defense a chance to get off the field."
And the Eagles are third-best in the NFL on third down.
So it all goes hand in hand.
“Honestly, it’s something that we demand out of each other, something we take pride in," Pro Bowl safety Malcolm Jenkins said. "I’ve been around groups, especially in New Orleans, and it’s something we wanted to emphasize this year, that not only do we want to break up passes and intercept passes but we want to set a physical tone and message when we come up and tackle guys.
"Because, especially the way we stop the run, a lot of teams will attack us on the perimeter. They’ll pack everybody in, block everybody, and then try to (hit short passes) and dare our corners to tackle.
"And all year we’ve kind of sent the message that we’re completely fine with that, and not only do our corners tackle, they show up with an attitude. I just think it gives us a physical presence that we love to carry.”
This is a different kind of group of corners from previous years in a lot of ways. They're younger, they're largely home-grown, and they're physical.
They're complete players.
Head coach Doug Pederson said their tackling ability is tied to a deeper understanding of the defense.
"You're seeing (it), then read and react," he said. "Where a year ago, there might have been hesitation there. A year ago, you probably would say we weren't making those tackles, and this year, we are."
Douglas, the rookie third-round pick, wasn't active on opening day, but with Ronald Darby out the last eight games he's averaged 42 snaps per game and proven to be not only solid in coverage but as sound a tackler as we've seen by a rookie cornerback in a generation. Probably since Allen in 1988.
“Corners gotta tackle," he said simply. "You’re not just a cover corner, you’re a tackling corner. Corey goes over it every day. We spend 10, 15 minutes on tackling every day after practice.
"We know the expectations of our room. Gotta make a tackle. We all pride ourselves on tackling. A lot of us have played safety — me, Jalen (Mills), Jaylen Watkins. I've always had a tackling mindset. Now that I’m playing corner, it’s different angles but it’s the same thing. We all just want to be complete corners.”
Because of the Eagles' ferocious pass rush, NFL-best run defense and big early leads, teams are throwing against the Eagles more than any other team.
Opposing teams are on pace to throw 645 passes against the Eagles, which would be eighth-most in NFL history.
But the Eagles are allowing only 5.8 yards per pass play, which is nearly a yard less than last year and their best since 2009.
We keep seeing quarterbacks try to unload the ball quickly to their outside receivers to avoid the pass rush and try to get yards after the catch.
And they keep failing.
"It's not just a cover league," defensive coordinator Jim Schwartz said. "You have to be able to tackle on short passes, and a lot of the NFL is short passes, limiting run after the catch and run game.
"Most run games, particularly a lot of stuff that we see and even some stuff that our offense runs, is just designed toward having the ball bounce or get to an unblocked corner and most offenses like that matchup. ‘Hey, we've got a good running back, maybe 230 pounds, and the guy that we can't block is not a linebacker or a safety. The guy that we are choosing not to block is a corner.’
"Well, you have to be able to answer that, and you do that with good tacklers. We put a lot of emphasis on it, but putting emphasis on it doesn't get the job done. It gets done with guys with shoulder pads and helmets out on the field that play with good technique.
"I think our corners have all embraced that, too. There's nobody in our locker room that says, ‘Hey, I'm just here to cover.’ They all understand how important it is."