I've been reading just a little on the "wide 9" defense employed by Detroit. I don't recall hearing the term until this year. It is used successfully by Detroit and it's a disaster in Philadelphia. It places the DE's way outside the O-line and trusts them to be fast enough to get to the QB without any moves at the line. Detroit has a number of fast DEs. Detroit has linebackers that can then cover the middle to stop any runs. Philadelphia doesn't have those LBs. Detroit has done a really nice job of developing this scheme to their talent. While Philadelphia's DE's are rushing full tilt toward the passer, they have weak coverage in between the DE's. Detroit is going to be a challenge for any non west coast offense team, because Detroit has what Philadelphia doesn't. All that money Philadelphia spent on secondary left the middle of the field as soft as the Pillsbury doughboy. Detroit is fast on the ends and tough in the middle. This is part of the reason Cutler was torn up. He was taking long drops and scanning the field.
This defense seems to reek havoc on a QB who cannot make quick decisions. A good west coast QB, like Aaron Rodgers, has the ability to make snap decisions and a quick release, thus foiling the whole purpose of the wide 9. Alex Smith isn't on a par with Rodgers, so we may not get to see what a true quick thinking west coast guy can do against the wide 9 until Thanksgiving day. This should make the game more interesting.
It can also be vulnerable to a good running back, like we saw with Fred Jackson against the Eagles. Even Forte had some success against the Lions wide 9. Adrian Peterson should have even more. I'm not sure what Green Bay's backs can do against it. This is another match-up I'm going to want to see.