The Dolphins are now a quarter of the way through their season - meaning it's time to do a review.  We looked at the offense yesterday, so now it's time to turn our attention to the defense - a unit that is ranked 7th in the NFL in total defense.  What a difference a year makes!

DEFENSIVE LINE
This unit has probably been the most changed - and most improved - from last season.  I think you need to credit the front office for this.  They saw what we all saw - a terrible run-stopping team in 2007 - and made the necessary changes.  And now this unit is, without question, one of the greatest strengths on the team.  They use a terrific rotation - thanks to the depth at the position - to keep their guys fresh.  In fact, it's rare if a single defensive lineman ever plays over 40 snaps in a game.

The addition of guys like Jason Ferguson and Randy Starks along with the drafting of rookies Phillip Merling and Kendall Langford have made this defense line one of the best in the entire NFL.  In '07, the Dolphins surrendered 153 yards per game on the ground - by far the worst in the league - and 4.5 yards per carry.  But '08 has been different, allowing just 82.8 yards per game and 3.3 yards per carry on the ground.

And if you go one step further, Football Outsiders - using their complex formula - ranks Miami's defensive line 9th in the league in "adjusted line yards" - the key stat in their rankings.  This unit also ranks 5th in the league in "stuffed percentage" - at 30%.  What that means, essentially, is that on 30% of opposing runs, the opposition runs for either 0 yards or negative yards on 1st down as well as one-fourth or less of the yards needed for a 1st down on second through fourth downs.  Perhaps a confusing, but nonetheless critical statistic.

Grade: A-

LINEBACKERS
Some of those figures we discussed above for the defensive line also need to be considered when you talk about the linebackers.  They've been another important cog in Miami's improved play against the run.  In fact, Channing Crowder, Matt Roth, Joey Porter, and Charlie Anderson have combined for 4 tackles for a loss through the team's first 4 games.

But the emergence of a pass rush despite the loss of Jason Taylor is what's most impressed me out of this unit.  Yes, a lot of credit has to go to Paul Pasqualoni and his defensive coaches - especially for the transition of Matt Roth from DE to LB.  But the players have stepped up and made plays.  Joey Porter has matched his '07 sack total of 5.5 already.  Matt Roth has 2 sacks in 4 games - just 1.5 sacks away from his career high.  And we've seen countless QB pressures from both Porter and Roth.  Thanks in part to the outstanding play of Miami's edge rushers, they are on pace for 48 sacks - 18 more than '07 and just one shy of Miami's franchise record of 49, set in 1983 and in 2005.

Now with that all said, I'm still a little disappointed in the play of Channing Crowder thus far.  He's in a contract year and I think he needs to show more play-making ability if he wants the Dolphins to bring him back.  Now, this isn't the time to debate if Channing should or shouldn't be back in Miami after this season.  But wouldn't you agree that - as of right now - it's hard to feel strongly one way or another?  I think he has tremendous potential.  But I need to see if week in and week out on a consistent basis.

Even still, as a whole, I've been damn impressed with the play of this LB group.

Grade: B+

SECONDARY
As was to be expected, the secondary has been this defense's Achilles' heel so far - and will continue to be.  But even with that said, there's been clear improvement over last year's unit.  Yes, I know the Dolphins ranked in the top 5 last year in passing yards allowed per game.  But that's only because teams chose to run all over them rather than to pass all over them.  Consider this: the Fins ranked 31st in the league in yards allowed per pass, surrendering 7.8 yards per attempt.  This season has seen an improvement, though, even though the numbers don't show it.  In fact, the Dolphins are surrendering 8 yards per pass in 2008.

However, this is a case where you have to look deeper.  You have to take into consideration the "Chris Crocker Dolphins" and the "Renaldo Hill Dolphins."  In the first two games, with Crocker starting at free safety, the Dolphins surrendered 11.9 yards per pass attempt and allowed 25.5 points per game.  When the change was made and Renaldo Hill took over as the starting FS, the Dolphins allowed just 5 yards per pass attempt and 11.5 points per game.  Quite a dramatic change.

Now you can't attribute that to just Hill's insertion into the starting lineup.  However, his teammates have acknowledged that Hill is the quarterback of the secondary.  He's the guy who makes the calls at the line of scrimmage.  And since the switch was made, communication amongst the defensive backs has improved - likely the #1 reason why the unit has performed better as a whole.

Yeremiah Bell has also been a beast back there.  His season-ending injury in '07 can't be stressed enough as one of the biggest causes for the disaster that was last year.  But he's back to being all over the field this season, making plays in run support and shutting down opposing tight ends in the passing attack.  Oh, and he leads the team in total tackles and solo tackles.  Impressive for a safety.

Grade: B-

Well that's all for now.  Let's hear what you guys think as we pass the quarter-pole of the season and march towards the midway point.