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Looking back at the “NFL Stats Correlations” spreadsheet found right here: https://spreadsheets.google.com/pub?key=r_LwM2btpEOj_rUCd6tM_4Q , we were able to make a couple interesting observations. We noticed that the highest correlation to wins, besides the obvious point differential and XPM & XPA differential (because more XP = more TD, which usually equals wins), is ∆ Adj Net Yards/Att. The correlation of ∆ Adj Net Yards/Att 0.838. You might be wondering what the triangle is – It means delta, or the differential. So the point is, the difference of Adjusted Net Yards per Attempt has a staggering correlation to wins. This means, that if you have the higher adjusted net yards per attempt, you are going to win and win often.
What is adjusted net yards per attempt exactly, though. Pro football reference defines it as:
ANY/A - adjusted net yards per passing attempt: (pass yards + 20*(pass TD) - 45*(interceptions thrown) - sack yards)/(passing attempts + sacks). See AY/A. Note that we are now using 20 yards per TD instead of 10, because of research by Chase Stuart at the p-f-r blog.
Source: http://www.pro-football-reference.com/about/glossary.htm
For AY/A, which it says to see:
AY/A - adjusted yards per passing attempt. This stat was introduced, and the reasoning behind it thoroughly explained in a book called The Hidden Game of Football, by Bob Carroll, Pete Palmer, and John Thorn. Note that we are now using 20 yards per TD instead of 10, because of research by Chase Stuart at the p-f-r blog.
Source: http://www.pro-football-reference.com/about/glossary.htm
AY/A has a 0.825 correlation to wins, which is also very high. But for this, we’re going to use Adj Net Yds/Att. Obviously, the way we are going to find ∆ Adj Net Yds/Att is subtract a team’s offensive adjusted net yards/attempt minus its defensive adjusted net yards/attempt. If you couldn’t tell by the definition and formula, this stats has everything to do with passing and nothing to do with running.
So we can assume that ∆ Adj Net Yds/Att can tell us who the best teams are, year in and year out. It’s certainly not perfect, meaning the team who leads in this category is not a shoe-in to win the Super Bowl or even the favorite. The Chargers led this stat each of the last two years, while loosing in the Divisional Round in 2009 and not even making the post-season last year. The team’s that came in second to the Chargers in 09’ and 10’ – the Saints and Packers, both won the Super Bowl.
So us being the numbers crunchers that we are, we decided to dig into this a little deeper. We tried to find the team’s with the Highest ∆ Adj Net Yds/Att and see how they fared. We came up with the top 15 teams in this stats, and the correlation to wins is very high. For this stat, however, we only went back to 1976. Why? Well, because the NFL was much different in this time. The reason we chose to end it at 1976 is because in 1975 the league average for ANY/A was 4.0, and in 2010 it was 5.7. In 1975, there would be three teams (including the SB winner) in the top 15 in this stat solely because the NFL was not a passing league back then. If we had continued it on through the first super bowl, the list would be dominated by 1960’s – 1980’s teams, and it would not at all be fair because of how paramount the passing game would become in the future compared to the “rushing” era of football. But anyway, here’s the top 15 teams after 1976 in ∆ Adjusted Net Yards per Pass Attempt.
| # | Team | Off. Adj Net Yds/Att | Def. Adj Net Yds/Att | ∆ Adj Net Yds/Att | Record | Playoff Outcome |
| 1 | 1991 Redskins | 8.3 | 3.3 | + 5.0 | 14-2 | Won Super Bowl |
| 2 | 1984 Dolphins | 8.9 | 4.4 | + 4.5 | 14-2 | Lost Super Bowl |
| 3 | 1987 49ers | 7.5 | 3.2 | + 4.3 | 13-2 | Lost Divisional Round |
| 4 | 1989 49ers | 8.5 | 4.2 | + 4.2 | 14-2 | Won Super Bowl |
| 5 | 2007 Patriots | 8.8 | 4.6 | + 4.2 | 16-0 | Lost Super Bowl |
| 6 | 1999 Rams | 8.0 | 4.0 | + 4.0 | 13-3 | Won Super Bowl |
| 7 | 1988 Vikings | 6.0 | 2.1 | +3.9 | 11-5 | Lost Divisional Round |
| 8 | 1977 Cowboys | 5.8 | 2.1 | +3.7 | 12-2 | Won Super Bowl |
| 8 | 2004 Colts | 9.6 | 5.9 | +3.7 | 12-4 | Lost Divisional Round |
| 10 | 1994 49ers | 8.1 | 4.5 | +3.6 | 13-3 | Won Super Bowl |
| 10 | 1984 49ers | 7.8 | 4.2 | +3.6 | 15-1 | Won Super Bowl |
| 12 | 1980 Eagles | 7.0 | 3.4 | +3.6 | 12-4 | Lost Super Bowl |
| 13 | 1996 Packers | 6.6 | 3.1 | +3.5 | 13-3 | Won Super Bowl |
| 14 | 1985 Bears | 5.8 | 2.4 | +3.4 | 15-1 | Won Super Bowl |
| 15 | 2002 Buccaneers | 5.7 | 2.3 | +3.4 | 12-4 | Won Super Bowl |
The record of these teams, the top 15 in adjusted net yards per pass attempt differential, is a staggering 199-38. That’s a .840 win %. All of these teams made the playoffs, 9/15 won the super bowl, 3/15 lost in the Super Bowl, and the other three lost in the divisional round.
Now let’s take a look at the leaders in this category in 2010:
| Team | Off. Adj Net Yards/Att | Def. Adj Net Yards/Att | ∆ Adj Net Yards/Att |
| Chargers | 7.8 | 4.6 | +3.2 |
| Packers | 7.2 | 4.1 | +3.1 |
| Patriots | 8.2 | 5.4 | +2.8 |
| Steelers | 7.0 | 4.3 | +2.7 |
| Buccaneers | 6.9 | 5.2 | +1.7 |
| Ravens | 6.4 | 5.1 | +1.3 |
| Eagles | 6.4 | 5.3 | +1.1 |
| Falcons | 6.2 | 5.2 | +1.0 |
| Chiefs | 6.2 | 5.4 | +0.8 |
| Giants | 6.1 | 5.4 | +0.7 |
| Colts | 6.5 | 6.1 | +0.4 |
| Saints | 6.0 | 5.6 | +0.4 |
| Titans | 5.8 | 5.6 | +0.2 |
| Bears | 4.8 | 4.7 | +0.1 |
| Jets | 5.4 | 5.5 | -0.1 |
| Cowboys | 6.2 | 6.4 | -0.2 |
| 49ers | 5.6 | 6.0 | -0.4 |
| Bengals | 5.5 | 5.9 | -0.4 |
| Lions | 5.5 | 5.9 | -0.4 |
| Raiders | 5.3 | 5.9 | -0.6 |
| Texans | 6.7 | 7.5 | -0.8 |
| Rams | 4.7 | 5.5 | -0.8 |
| Broncos | 6.4 | 7.3 | -0.9 |
| Dolphins | 4.9 | 6.1 | -1.2 |
| Redskins | 5.4 | 6.6 | -1.2 |
| Browns | 4.7 | 6.0 | -1.3 |
| Bills | 4.9 | 6.3 | -1.4 |
| Vikings | 4.1 | 5.7 | -1.6 |
| Seahawks | 4.7 | 6.5 | -1.8 |
| Cardinals | 3.7 | 5.9 | -2.2 |
| Jaguars | 5.2 | 7.5 | -2.3 |
| Panthers | 2.9 | 5.4 | -2.5 |
The Chargers, from 1976-2010, were the ONLY team to lead the NFL in ∆ Adj Net Yds/Att and not make the playoffs. Talk about underachieving. But we can see that the stat does correlate pretty well to wins. 11 of the top 15 in this stat made the playoffs. The only team left off was of course, the very team that deserved to be left off, the 7-9 Seattle Seahawks. We can see that underrated, or underachieving teams, were the Chargers, Buccaneers, Giants, and Titans. And the overrated, or overachieving teams, were the Bears, Jets, and Seahawks. You’ll see how we predict these teams, and all 32 teams, end up in the 2011 season when we post our Team by Team previews in July.
We’ll be posting more about this in the upcoming weeks. We’ll crunch even more numbers to see what percentage of Super Bowl winners led the NFL in ∆ Adj Net Yds/Att, and more.
Thanks for reading. Hope you enjoyed this. Don’t forget to follow us on twitter!
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