Below, I've created a table of every player who recorded a sack, quarterback hit, interception, or pass defense this season. Take a look:
First off, while Miami's defense certainly didn't play well this year, they were in no way awful, and truth be told they were hardly different from last year. People have to remember that the strength of schedule was vastly different between this year and last year, so staying put on defense just looked a whole lot worse this year. The performance was still pretty similar though.
To wit, Miami finished 2009 with an overall defensive DVOA of 3.1% and a pass defense DVOA of 1.5%, good for 11th in the league. In 2008, they finished with an overall defensive DVOA of 3.0% and a pass defense DVOA of 5.3%. So Miami was actually marginally better in pass defense in 2009 than 2008! Remember, it's adjusted for the opposition, which makes a huge difference when you go from facing Matt Cassell, Joe Flacco, Seneca Wallace, JaMarcus Russell, Marc Bulger, Shaun Hill, and Tyler Thigpen in 2008 to facing Tom Brady (twice), Peyton Manning, Drew Brees, Matt Schaub, and Ben Roethlisberger in 2009.
Seriously, those two lists could not be more different. It's amazing how lucky Miami got in 2008 with such a cupcake schedule (and Tom Brady's injury). That's the biggest reason why I was hesitant to see Paul Pasqualoni get fired. His defense played the same, just against a schedule infinitely tougher. Obviously, it's a black mark against him that he wasn't able to get them to improve, but there's no guarantee Mike Nolan will be able to do that either and there is something to be said for continuity.
As far as the individual pass defense numbers go, Miami did very well in the sack department, but I think they could have gotten more quarterback pressures. They were finishing the job when they got there, but not getting there quite enough.
And the defense definitely needs to create more turnovers. Vontae Davis did a nice job forcing the issue all year, although he needs to work on improving his lockdown coverage skills. Sean Smith, supposedly a ballhawk, didn't get a single INT, and he started the whole year.