Football Outsiders lists six Ravens defenses in the best of the last 30 years

Defense. That has been the Baltimore Ravens identity and reputation over the last seventeen years. It is who they are, and it is something general manager Ozzie Newsome worked hard to build and maintain this offseason. Newsome is trying to turn a good but overrated defense from a year ago into a great one, and the pieces are in place for that to occur in 2017.

ESPN Insider, with the help of Football Outsiders DVOA advanced-metric system, ranked the thirty best defenses over the last thirty years. Six Ravens defenses were among the thirty defenses listed, and you can make a case a couple of them should be higher than they are. That's how tough this list is to rank because of the fact there are so many great defenses in NFL history, and you don't really need advanced metrics to put them together. They come together on their own.

Below is where the six Ravens defenses were ranked and the Football Outsiders statement on each of them. Let’s begin with the first Ravens defense on this list starting with a year that was right in the prime of the Ray Lewis and Ed Reed era; The 2004 defense.

26. 2004 Baltimore Ravens. -19.9 percent. "Baltimore's defensive record over the past 20 years is just as impressive as the record in Pittsburgh. Since they moved to Baltimore in 1996, the Ravens have ranked No. 1 in defensive DVOA four times and No. 2 three other times. The 2004 Ravens defense limited Peyton Manning and Tom Brady to just one touchdown combined, but they lost both games because their offense was horrible."

23. 1999 Baltimore Ravens. -20.8 percent. "The Ravens held opponents to just 4.06 average yards per play in 1999, the fourth-lowest figure since the expansion to a 16-game season in 1978. That's actually lower than the legendary 2000 Ravens defense (which allowed 4.29 yards per play ). But overall, the 1999 Ravens weren't as good as the 2000 Ravens because they were just average in the redzone and forced a low number of fumbles."

13. 2003 Baltimore Ravens. -24.8 percent. "In 2003, The Ravens had five games with at least four takeaways and another six games with three takeaways (including their 20-17 loss to Tennessee). They also allowed a league-low average of 4.23 yards per play.

12. 2006 Baltimore Ravens. -25.1 percent. "This edition of the Ravens defense led the league with 28 interceptions and was only one of five defenses since 1990 with 60 sacks in a season. Adalius Thomas and Ed Reed were first team All-Pro, and four other Ravens defenders were named to the Pro Bowl."

Disclaimer: They combined the 2008 Pittsburgh Steelers defense with the 2008 Ravens defense in this portion of the article. The Steelers were No. 7.

6. 2008 Baltimore Ravens. -27.9 percent. "This was the pinnacle of the defensive rivalry that has defined the AFC North in the 21st century. Baltimore was No. 1 against the run and No. 2 against the pass. Pittsburgh was No. 2 against the run and No. 1 against the pass. The Steelers were the better defense during the regular season, and their average of 4.3 net yards allowed per pass is the best figure of any defense in the past 20 years. But the Ravens move slightly ahead once we consider the postseason because they shut down the Miami and Tennessee offenses in their first two playoff games. The Steelers had the last laugh, however, beating Baltimore 23-14 in the AFC Championship Game and then going on to win the Super Bowl. The All-Pro first team featured two Ravens (Ed Reed and Ray Lewis) and two Steelers (James Harrison and Troy Polamalu)."

3. 2000 Baltimore Ravens. -33.1 percent. "We can look at the 2000 Ravens in two ways. We can acknowledge that many of the regular-season records they set came courtesy of one of the easiest defensive schedules in history. Or, we can focus on the fact that the Ravens are almost as superlative in Football Outsiders' advanced stats, even after we've adjusted for that super-easy schedule. The Ravens have the best run defense DVOA of all time, and they famously allowed 2.7 yards per carry for the entire regular-season. They had four shutouts and held opponents to 10 points or fewer in 11 of 16 regular-season games. But the Ravens really became legends in the playoffs, allowing just 23 total points in four games to Denver (No. 3 in offensive DVOA), Tennessee (No. 16), Oakland (No. 6), and the New York Giants (No. 8). That postseason performance moves the Ravens up from No. 12 to No. 3 on this list."

First off, having six Ravens defenses on this list is a testament to just how good Baltimore really has been on the defensive side of the football. You can put any of these defenses on this list and not many would complain. There are even some Ravens defenses you can make a case should be on this list, like the 2001 or 2011 units. Those two were really good in their own right.

When it comes to the 2000 defense, I've seen Football Outsiders make the case before that the 2000 unit had the benefit of an "easy" schedule without facing many good quarterbacks. The fact they had them at twelfth because of their regular season speaks to volumes to how they felt about the schedule.

Even moving them up to No. 3 because of their postseason performance due to the fact they allowed 23 total points doesn't really shed the true light on it when you realize they only gave up one touchdown during that run. They faced offenses that featured Rod Smith, Steve McNair, Eddie George, Derrick Mason, Frank Wycheck, Rich Gannon, Jerry Rice, Tim Brown, Tyrone Wheatley, Tiki Barber, and Amani Toomer. Through all of that, they only gave up one touchdown. That's just insane and something your not going to see in today’s NFL.

As far as their regular-season, or the "super easy" schedule as Football Outsiders would say, they forget to mention that the unit had to overcome a lot of deficiencies on the offensive side of the ball during that regular season. The biggest, which I was very surprised Football Outsiders never brought up, was that for the whole entire month of October the Ravens offense went without a touchdown.

That defense during that stretch could've easily rebelled and cause a stir in the locker room that they were doing their job and the offense was not holding their end of the bargain. There was even a quarterback change from Tony Banks to Trent Dilfer. Despite this, the defense never folded and kept going strong despite the lack of an offensive touchdown. In order for the Ravens to make the playoffs, let alone win the Super Bowl, that defense had no choice but to be great. The only two defenses that were above the 2000 Baltimore unit are the 2002 Tampa Bay Buccaneers and the 1991 Philadelphia Eagles.

Do you agree with Football Outsiders placement of each Ravens defense, and do you agree with their assessment of the 2000 unit?