WE'RE GOING to find out a few things about how much the Eagles have really improved over the past few weeks, when they host the 11-2 Arizona Cardinals Sunday night. One of the questions to be answered is how Sam Bradford and the offense will stack up against a dominant, fourth-ranked defense that blitzes more than any other group in the NFL.

"I think they're right at about 50 percent," Eagles coach Chip Kelly said this week. Actually, the figure is 46.9 percent, according to STATS. "So one out of every two snaps, somebody (extra) is coming, and they bring them from all different areas."

The Eagles got in something of a dry run for the Arizona blitz last Sunday against another blitz-heavy team, Buffalo, and they did OK. The Eagles Insider podcast said Bradford was blitzed on 14 of 43 dropbacks and completed eight passes for 87 yards, and three passes were dropped. Against all-out, six-man Buffalo blitzes, Bradford was even more efficient, 6-for-9 for 69 yards, with two drops.

"I know the teams that have blitzed us the most, we've won (the games)," center Jason Kelce noted. Those teams would be Buffalo, coached by Rex Ryan, and the New York Jets, back in Week 3, coached by Todd Bowles, who was the Cardinals' defensive coordinator last year when they hosted a 24-20 victory over the Eagles. The Cards still run Bowles' 3-4 setup, under James Bettcher, formerly their outside linebackers coach.

Blitz pickup aside, the Eagles' 24-17 victory over the Jets was keyed by the Birds' running game; Bradford threw for a season-low 118 yards that day.

"We're really attuned to the blitzing" this week, Kelce said. "Understanding of who the offensive line has, who the backs have, who the tight ends have, whoever's in the protection. On top of that, the quarterback needs to know who he has" if there's an unblocked rusher.

Kelce said that most of the time, when you see blitzes get home, it's because there's an unblocked rusher by design and the quarterback just doesn't get the ball out. "Obviously there's ones where guys just get beat in protection, or there's a missed assignment, but the missed assignments are usually few and far between."

The Cardinals are sixth in the league in opponent passer rating vs. the blitz (77.3). Eight of their 16 interceptions and 14 of their 24 sacks have come on blitzes.

Against the blitz, as in most other areas, Bradford has done better lately than he was doing earlier in the season, when he really struggled processing a new offense, while trying to get up to game speed after missing a season-and-a-half with knee injuries. He's still just 27-for-59 on the season when teams send an extra rusher, according to ESPN, 45.8 percent, and he's averaging just 3.56 yards per blitz pass attempt, with two sacks, two touchdowns and an interception.

Kelly said Bradford's progress against the blitz also reflects progress by the o-line and the receivers, "knowing when things are hot and when things aren't hot."

"I think (Bradford) has got a better feeling and a better understanding in terms of what we're doing from an attack standpoint," Kelly said.

Bradford said it's easy to get confused against the Cardinals, with disastrous results.

"One of the unique things about this defense is they run a lot of different personnel groups with those blitzes, too," Bradford said. "The communication between Kelce and our tackles and our running backs, and making sure we have everyone properly identified will be a real key to us protecting and blocking the blitzes.

"You can get into trouble against this team when you misidentify people and you're not sliding to the right guys."

The Eagles' use of tempo might make it harder for Arizona to change personnel groupings. Blitzing also gets tiring, so if your offense can stay on the field, you might be able to force the opposing team to pull back a little eventually.

Right guard Matt Tobin said it's an advantage that the Eagles will be at home, and will be able to hear Bradford.

"You can at least communicate with each other, instead of (using) hand signals and stuff like that," Tobin said. "They've got all sorts of different looks they do. (Offensive line coach Jeff Stoutland) has done a great job so far letting us know what their tendencies are and stuff like that. Basically it comes down to listening to what Kelce calls and making sure everybody's on the same page."

Right tackle Lane Johnson said that in addition to running the protections flawlessly, the Eagles will have to run the ball effectively. Ryan Mathews looked a little sluggish last week, in his first game back from a three-game concussion absence; he should be sharper. It will be interesting to see if Mathews continues to start and get more snaps than DeMarco Murray.

Backs also play a role in blitz protection.

"We just have to be on our toes and expect anything," Mathews said. "Listen to the quarterback and the line, know who they got and who you got."

The Cardinals sometimes put as many as seven defensive backs on the field, including 6-1, 216-pound Deone Bucannon, drafted as a safety and wearing No. 20 but functioning as an inside linebacker.

Kelly said Bucannon "may be the lightest linebacker in the league . . . they are getting great production out of him. He's a physical football player . . . I think he's one of the keys to their defense right now."

The Cardinals consider the back seven pretty much interchangeable in terms of rushing vs. covering. Bucannon and fellow linebacker Kevin Minter seem to get a lot of blitz duty, as does safety/nickel corner Tyrann Mathieu, one of the handful of top defensive impact players in the NFL.

"I think our guys have done a good job" at blitz pickup this season, Kelly said. "They work extremely hard at it. They haven't had many clean shots at the quarterback, and there have not been (many) missed assignments when we thought somebody was supposed to be picked up."

On Twitter: @LesBowen

Blog: philly.com/Eagles