ESPN and Football Outsiders are releasing a series of articles, playing off ESPN’s “30 for 30” television series, in which they go back over the past 30 years and rank the 30 best units, and individuals, in that span. They started with the best offenses on Monday and released the best defenses on Tuesday. The Miami Dolphins did not appear in either of those lists - but they did show up in the “worst defenses of the last 30 years” subset in Tuesday’s article.
The 1987 Dolphins received a +24.4 percent grade based on Football Outsider’s DVOA (defense-adjusted value over average) metric. The article explains, the DVOA “metric accounts for every aspect of defense: how well teams prevent yardage, how often they get turnovers, and how well they keep points off the board. DVOA measures success on each play, defined using down and distance, then compares it to an NFL average baseline adjusted for situation and opponent. You can read more of the details here -- and yes, defensive DVOA adjusts for opposing offenses, not defenses, but we still call it DVOA. The metric is built to balance a measurement of how well a team has played in the past with a forecast of how well a team will play in the future.”
They also add “Note: A negative defensive DVOA is good and 0 percent represents the league average, so a defense with a minus-30 percent DVOA rated 30 percent better than an average unit. Also, stats other than total defensive DVOA represent the regular season only unless noted.”
Based on that explanation, the Dolphins’ 1987 defense was 24.4 percent worse than the league average. The good news is, they were not the worst defense in the article, the bad news is, according to Football Outsiders, there were only two defenses, the 2000 Minnesota Vikings (+25.3 percent) and the 2015 New Orleans Saints (+26.1 percent), who were worse in the last 30 years.
Of the Dolphins’ dismal rating, Football Outsiders wrote:
In case you are wondering how Dan Marino never won a Super Bowl, the Dolphins were dead last in defensive DVOA in 1987. And 1988. And 1989. And 1991.
That 1987 season saw Miami’s offense rank first in passing yards, 23rd in rushing yards, and 4th overall. The defense meanwhile was 26th overall, 21st against the pass and 25th against the run. Miami finished the season 8-7, third in the AFC East.
Now, to be fair - the 1987 season was also the strike season, so the Week 3 games were cancelled for that season (thus the 15 game record) and Weeks 4 through 6 were played with replacement players. However, the DVOA should adjust for that, since all teams were using replacement players those weeks, making the league average DVOA reflective for the season and leaving Miami’s 24.4 percent worse than the rest of the league an accurate reflection of the team’s defensive struggles.
The Dolphins’ defensive struggles through the middle of Marino’s career were a large part of why the team never got back to a Super Bowl after the 1984 season. Seeing the team listed as the worst team by DVOA in the league in 1987, 1988, 1989, and 1991 simply reinforces that fact.