New Orleans has allowed 4,217 passing yards this year (which includes yards lost by the opposing team on sacks) on 538 dropbacks, which is already pretty bad. That translates to a 7.84 Net Yards per Attempt allowed average, which is the worst in the NFL by half a yard per attempt. But where things get really bad is in touchdowns and interceptions. New Orleans has allowed an unbelievable 43 passing touchdowns through 15 games, the most in NFL history. In addition, the Saints have intercepted just 8 passes, tied for third fewest in the league this year.
That translates to an 8.77 Adjusted Net Yards per Attempt average, after giving 20 yards for each touchdown pass and subtracting 45 yards for each interception. That is, by a decent measure, the worst rate in NFL history. The current record belongs to the 0-16 Detroit Lions, who allowed 8.53 ANY/A. Only three other teams — the ’81 Colts, the ’69 Saints, and the ’63 Broncos — have even allowed 8.00 ANY/A over a full season.
Of course, the current passing environment is more passer-friendly than ever, so that’s not the end of the story. The league average ANY/A this year is a whopping 6.30, although it drops to 6.22 ANY/A once you eliminate the Saints.1 The standard deviation of ANY/A for the 32 defenses is 0.955; that means the Saints defense has been 2.67 standard deviations worse than average.
A couple of years ago, I used this exact same methodology to quantify how great the 2013 Seahawks pass defense really was. Seattle ranked as the 4th best pass defense since 1950, courtesy of a 3.19 ANY/A average, a league average (after removing Seattle) of 5.98, and a standard deviation of 0.95. That means Seattle was 2.93 standard deviations above aveage. Given that 2013 and 2015 have had the same standard deviations, we can make the analysis a little bit simpler. Think of it this way: Seattle’s defense was about 2.79 ANY/A above average, making it a little bit more extreme than this year’s Saints (which is 2.55 ANY/A worse than average).
In that Seahawks post, I also included a list of the worst pass defenses in history, using this same methodology, known as a Z-score. At 2.67, the Saints would be the 6th worst pass defense by this measure, behind only the ’63 Broncos, ’81 Colts, the ’78 Colts, the ’99 49ers, and the 2006 Redskins. I don’t quite remember that last team, but a 32nd-place ranking in NY/A, TDs, and INTs is a pretty good sign of a historically bad defense.
I’ll note that off those teams, only the ’99 49ers faced more pass attempts than the current Saints defense, and by the end of the season, New Orleans will have passed them in that regard, too. Given that it is harder to be an extreme outlier over a large number of pass attempts, there’s an argument to be made that this Saints pass defense is the worst ever. But I’ll wait until after the season to run some tests on that.2
- When I ran the calculations in the Seahawks post, I removed each team when calculating league average, so I repeated that here. [↩]
- I’ll also note that the Saints have allowed passing first downs on 38.1% of all pass plays this year, most in the NFL. Although not by that much, I suppose: Miami has allowed first downs on 36.6% of passing plays. [↩]