What makes a great NFL offense? Is the team with the most points the best offense, or do we look for the offense that most efficiently gains yardage? What if a team scores points because of great special teams, or because it was often given good field position? How much yardage does it take to counter a higher turnover rate? And shouldn't all these questions consider how good the defense is on the other side of the field?
These are the kinds of questions Football Outsiders has been analyzing with our advanced metrics since we launched in 2003. Our DVOA (defense-adjusted value over average) metric accounts for all of this, measuring success on each play based on down and distance, then comparing it with an NFL average baseline adjusted for situation and opponent. (You can read more of the details here.) It's built to balance how well a team has played in the past with how well a team will play in the future.
But we aren't just interested in looking at the game today. We're also football historians who love to shine a light on underrated players and teams of the past. That's why we've also spent time going back to past years of the NFL to collect play-by-play data and run our DVOA stats on as many NFL seasons as possible. Ratings each year are normalized, accounting for changes in the NFL's offensive environment over the past 30 years.
This offseason, we finally introduced 1987 and 1988 ratings on our website. And since we now have DVOA for every season from 1987 to 2016, we can now do our own Football Outsiders "30 for 30" with 30 years of play-by-play breakdowns. We'll be doing that all week, counting down the 30 best teams of the past 30 years according to DVOA: offense, defense, special teams and overall.
You can find DVOA stats for all 30 seasons on the stats pages at Football Outsiders, but the ratings we run here will be a bit different. That's because for the first time we've also added in postseason performance, boosting teams that went on strong championship runs and lowering teams that dominated the regular season only to trip over their own feet in the playoffs.
Note: 0 percent DVOA represents the league average, so an offense with a +30 percent mark rated 30 percent better than an average unit. Also, stats other than total offensive DVOA represent the regular season only unless noted. Special thanks to Jeremy Snyder, who did most of the transcription work on the late 1980s and early '90s.
30. 1998 Minnesota Vikings
One of the quirks of the DVOA system is that it seems to underrate some of the most powerful offenses in NFL history, all from around the turn of the century: the 1998 Vikings and the 1999-2001 Rams. Why are these offenses, all of which scored more than 500 points, not ranked higher in DVOA? There are three reasons.
1) Schedule: DVOA is adjusted for the strength of opponents, and all four of these teams played extremely easy schedules. The 1999 Rams, in particular, played the easiest schedule of opposing defenses of any team in the past 30 years.
2) Domes: DVOA adjusts for the fact that offenses are generally better indoors, and each of these four teams played at least 10 of 16 regular-season games indoors.
3) Long touchdowns: DVOA limits the value of extra-long touchdowns, because explosive plays are difficult to duplicate. Often the only real difference between a 40-yard touchdown and a 60-yard touchdown is where the initial line of scrimmage was, and consistently moving the chains is usually a better indicator of future offensive success than depending on long touchdowns. However, it can certainly be argued that long touchdowns are more consistent for teams at the extremes, and no player over the past 30 years could consistently destroy defenses deep more than Randy Moss.
29. 2000 St. Louis Rams
The 2000 Rams couldn't follow up on their Super Bowl title because the defense collapsed, ranking 27th in DVOA that season. However, 2000 was the best year for the "Greatest Show on Turf" offense, even though Kurt Warner got injured and was replaced by Trent Green for five games. The Rams set the all-time NFL record by averaging 6.98 yards per play; no other team since 1960 has been over 6.7. The 2000 Rams also set an all-time record for highest team rushing DVOA (+36.5 percent).