You can do a number of different things out of quarters coverage. Depending on the number of WR's or WR/TE combo to a given side of the field, you can play a standard quarters cover 4 look, you can match it (generally the CB takes the #1 WR unless the inside/slot/TE crosses his face before a given yardage mark. In most cases I've seen it's 7-10 yards, and this is where we got crossed up on that long pass to Donald Brown late in the Colts game) or you can play a cover 4 shell, but play man under, which is really a 2-deep S look.
Generally, from what I know from Parcells' teams, is that he likes CB's who have size a la Smith and Davis, who can play the run well and have two safeties who tackle well that play high over the top. Obviously Wilson and Bell have both struggled significantly, especially with the trio of TE's we've faced right off the bat who can stretch the field vertically, and when you have a WR who can do that on the other side like all three teams we've faced (White, Wayne, Jackson) you can have a lot of open routes underneath. This has happened quite a bit in base personnel packages (i.e. pretty much every time you've seen Porter/Taylor/Crowder/Ayodele/Torbor chasing a back or WR coming all the way across the field.
The way to neutralize that is pass rush. Miami hasn't had much of a pass-rush, and you're not going to generate it against Peyton Manning because he's just too quick getting the ball off. That said, Joey Porter and Jason Taylor have been dissapointing thus far; though I think a lot of that is Pasqualoni's scheme. Watch the Jets defense or Baltimore's or Pittsburgh's - they all overload one side of the line, or they'll pull a Nick Saban special and rush two and three guys through the same gap. Here's a prime example of a play at LSU.
http://www.youtube.com/watch?v=R211e6JdVew
Watch LaRon Landry come on the blitz, then in the replay, notice how Landry trails a stunt through the strongside A gap after the DT game (crossed through the backside A gap before Landry gets through the line). The Jets, Ravens, Steelers, etc. do plenty of this.
Here's another example from the Rex Ryan D from Baltimore last year.
http://www.youtube.com/watch?v=_ZoDDYkoKi4
Bart Scott, an ILB is going to overload the right side of Pittsburgh's O-line, then Baltimore drops the OLB from that side into zone coverage and brings a nickel safety from Scott's side (still the right, that's 4 guys) all the way over to the backside B gap on a blitz with Ray Lewis, so in essence you've got 5 guys putting pressure on Roethlisberger through 3 gaps on the offensive line as opposed to Miami trying to bring 1 guy through every gap - if you're a step slow, you don't get close to the QB and bad things happen. With Ryan's scheme, sure a draw through the right gap will get you a chunk of yardage, but you've got at least a 3-2 advantage in pass-rushers vs. blockers coming through and that will make life a LOT easier for your DB's, especially those 2 high safeties to fly up and make a read. This is what Wilson and Bell both excel at, but they haven't really had opportunities to do it since they've been asked to cover TE's who can stretch the field but don't have any pass-rush to help them out.
That's my biggest gripe so far this year on defense. Pasqualoni simply lines up man-on-man and goes straight through gaps with his blitz pacakges. Most QB's in the NFL won't be rattled by this unless you have guys off the edge who can get to the QB and thus far Taylor and Porter have done none of that.
Here's a prime example of it from the Monday Night game against Peyton Manning.
http://www.youtube.com/watch?v=z5yA4tAIadY&feature=related
First of all, this is just plain stupid on Pasqualoni's part in calling a Cover 1 (man-to-man outside with Gibril Wilson the lone high safety) and bringing the house. Notice, not one single overload occurs in this blitz; Manning recognizes it, and the rest is history. Manning sees that Will Allen and Nathan Jones are playing match coverage to the 2 WR side, and Will Allen gets burned when he flies up and misses the tackle. You can tell it's match because Nathan Jones doesn't even look at Manning for a read, he completely turns his back and reads to the outisde in case Garcon crosses - this may have been the original play, but Manning audibled to a screen and burned Pasqualoni. Also, notice now the pass-rush isn't even close to Manning by the time he releases the ball.
Yes, tackling has been poor at times, but I think ultimately with quarters coverage, it allows you to bring pressure like the LSU play above both with inside and outside LB's and safety blitzes - Miami hasn't done this at all that I've noticed in any game yet. Personally, if I were Jeff Ireland, both Joey Porter and Jason Taylor, as well as Reggie Torbor and Charlie Anderson, wouldn't be Miami Dolphins after this year. Crowder I think is better suited for playing the WILB spot, where Ayodele currently plays, and I think he could thrive there next to a Brandon Spikes/Rolando McClain next to him with better pass-rushers outside.
I've thought Smith has been pretty good - better than I imagined he would be as a rookie. I think Vontae Davis will assume Will Allen's role before long; but that's not necessarily a bad thing as Allen thrived playing in the slot in Saban's D in 2005. If you can have Davis and Smith on the outside, and Will Allen as your nickel, you can use Nate Jones, or bring Yeremiah Bell into the slot (another thing Saban did in 2005 effectively) in dime situations with Culver over the top.
As a whole, I've been very impressed with our run defense, but I think in order to improve the quarters coverage, it's got to start with the pass-rush, and that's just one area Miami (primarily Pasqualoni's scheme) has sorely lacked this year.
