Ok, so I've never done a fanpost, and if you'd asked me 10 minutes ago I would have said I never would.  I'm just happier in the peanut gallery, but after a discussion with some Bronco fans over on their site I felt it was time to bring some more attention to www.footballoutsiders.com.

You might already be familiar with them, they have a post on espn.com from time to time,they release a book every year called Pro Football Prospectus (they work closely with the pro baseball prospectus people that you may or may not be aware of), and I've mentioned them here before.  I think they explain themselves best, so I'll borrow their words:

Imagine two running backs who each gain three yards. Player A gains three yards under a set of circumstances where the average NFL running back gains only two yards (for example, third-and-1), it can be argued that Player A has a certain amount of value above others at his position. Likewise, if Player B gains three yards on a play where, under similar circumstances, an average NFL back would be expected to gain five yards (for example, second-and-15), it can be argued that Player B has negative value relative to others at his position.

I'll use the example of tackles.  A common way to determine how good a linebacker is is by using how many tackles he gets in a year. That is a terrible way to look at things.  A tackle 2 yards behind the line of scrimmage is worth light years more than a tackle 5 yards down field.  But a tackle 5 yards down field on 3rd and 6 is worth light years more than a tackle 6 yards down field on 3rd and 6.  Traditional stats tell you very little about actual success, a yard is not a yard is not a yard.

What football outsiders has done is pretty amazing. They've gone back to 1995 and entered every play, offense, defense and special teams, into a database and applied their success rates accordingly.  Eventually what they spit out is a couple different stats, the big ones are DVOA and DYAR (recently changed from DPAR). 

You'll have to visit the site and learn about them for yourselves, they're not simple things to explain.  But, if you don't care or want to know a single thing about them outside of how to read them I can help.  0% is average.  Anything above 0% is good for offense, bad for defense.  Anything below 0% is good for defense, bad for offense.  A little strange, but it makes sense if you think about it.  Everything is measured in success points, negative success points means the offense went backwards (or didn't achieve what it should), which is a win for a defense.  Whats good for one is bad for the other.  So when you see the Patriots D ranked first with a DVOA of a large negative number it's not a typo.

Football will never be boiled down into pure stats the way baseball has, there are far too many variables.  However footballoutsiders has the best stats to use for intelligent football discussions.  And, beyond the stats, they have a lot of great articles, everything from breaking down teams and games to the latest waiver wire news and what not.  I love the site and encourage you all to check it out.