Okay on to some NFL geekery.
Whenever teams are ranked in the NFL in terms of offense and defense, invariably the stat used is "total" offense and "total" defense. This means total yards or total yards allowed, respectively. But this is such a poor ranking, considering it's not yards that win you the game, it's points.
But if you just rank on points, it really doesn't tell you the efficiency of the team's offense or defense. That's why I decided last year before the playoffs to try and rank the teams by points/yard. More specifically:
For offense: Rank by offensive points scored per yard (OPSPY). Offensive points scored is: rushing and receiving touchdowns, point after, field goals and 2-point conversions minus safeties (as a penalty to the offense). This will benefit teams with efficient offenses as well as teams with defenses and special teams that give their offense good field position.
For defense: Rank by offensive points allowed per yard (OPAPY). Offensive points allowed is: rushing and receiving touchdowns, point after, field goals and 2-point conversions. This eliminates kick returns, int returns, etc. from the equation and doesn't punish defenses for offensive or special teams mistakes that lead to scores (it will punish teams that have offenses or special teams that leave their defense in poor field position, though)
I also made an "aggregate" ranking where defensive points allowed per yard are subtracted from offensive points scored per yard. (PPYA)
So I decided in some down time to do it for this season through Week 3. There are some surprising results.
Full Data Spreadsheet for Week 3 (converted to HTML)
Through Week 3
1. New York Giants
2. San Diego
7. San Francisco
9. St. Louis
13. Tampa Bay
14. New England
15. Kansas City
22. New Orleans
25. Green Bay
29. New York Jets
5. Tampa Bay
10. Kansas City
13. New York Jets
17. St. Louis
20. San Diego
21. Green Bay
23. New York Giants
28. San Francisco
30. New Orleans
31. New England
3. New York Giants
5. San Diego
6. Tampa Bay
10. Kansas City
16. St. Louis
17. San Francisco
24. New York Jets
25. Green Bay
27. New England
31. New Orleans
It's too early to draw conclusions, but some early interesting notes:
- The old adage "Defense wins championships" shows up in these rankings. Of the four teams with no losses, they are all in the top 5 of Offensive Points Allowed Per Yard. The first team with a losing record is at #7 in this ranking (Chicago).
- Offense (at least in this measurement) isn't nearly important to winning as defense, although there is a loose correlation. But in the top 10 of Offensive Points Scored Per Yard are four teams with losing records and only one of the unbeaten teams (Cincinatti). Two unbeatens are in the bottom six (Indianapolis and Washington at 27 and 31, repsectively).
- New England looks bad in these rankings, and their losses on defense really show up. At the end of the regular season last year the Patriots ranked #1 in OPAPY and #3 in OPSPY, #1 Aggregate. This year after three games they are #31 in OPAPY and #14 in OPSPY, #27 Aggregate. This could be a sign of their tough early schedule but it's not a good sign for the defending champs that their defense has fallen almost all the way to the bottom in efficiency and their offense has fallen to mediocre.
- Indianapolis' defense is certainly far underranked by a yards only approach. They are by far the most efficient defense in the league at 0.0165 OPAPY. Other underrated defenses if just looking at yards allowed include Cincinatti, Pittsburgh Atlanta and Kansas City. All are in the top 10 and all moved up by more than 10 rankings when switching to OPAPY.
- Overrated defenses include: #14 Baltimore (#3 in yards allowed), #22 Carolina (#13 yards allowed), #27 Houston (#5 yards allowed) and #31 New England (#11 yards allowed)
- Indianapolis' offense, however, does have problems. They rank #27 in OPSPY. Whatever Tony Dungy says about them being efficient they aren't. They rack up yards without scoring (or only scoring field goals), highlighting their red zone problems. A highly underrated offense by when comparing the total yards are the New York Giants. They are scoring an amazing .0965 offensive points per yard - higher than last year's #1 San Diego which scored at a .0776 clip.
- Overrated offenses include: #17 Philadelphia (#1 total yards), #18 Oakland (#8 total yards), #22 New Orleans (#11 total yards) and #26 Cleveland (#10 total yards).
Its' too early to draw conclusions but it's going to be interesting to see how these numbers change over the course of the season. I'm going to try and do this every week.
I'm sure more astute statisticians and NFL statheads will find faults in this approach. I'm certianly not claiming to be as good at football stats as the guys at Football Outsiders. This is just a little toying I wanted to do looking at points/yard and see how it stacks up.