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The Simple Rating System: 2007 Offenses and Defenses

Posted by Chase Stuart on June 17, 2008

Yesterday, we looked at the simple rating system for each team. One of the nice things about the SRS is that we can also break it down into components, such as offense and defense. To be sure, these are far from perfect -- points scored is just a proxy for offense, and points allowed is just a proxy for defense. But for the most part, they're pretty good.

We can include the offensive strength of schedule ratings, too. The Pittsburgh Steelers scored 393 points last year, and the average team scored 343 points, meaning Pittsburgh scored 2.9 PPG more than average. But the Steelers played the Rams, the Cardinals, the Dolphins, Cincinnati twice, Denver, and Cleveland twice. That's half their schedule against really bad defenses, all of whom allowed more than 3 PPG above average (which you can see on the second chart). The Steelers offensive SOS (i.e., the quality of the defenses the Steelers' offense faced) was just under 2.0 PPG easier than average, which means the Steelers were "morally" about 0.9 PPG better at scoring points than average. The table below shows every team's grade.

	Off Rat	  Off SOS
nwe	 15.86	   0.73
dal	  7.81	   1.06
ind	  6.61	   0.18
gnb	  5.67	   0.17
jax	  4.81	   0.81
sdg	  4.33	   0.27
nyg	  2.82	   1.20
hou	  2.54	   0.54
cle	  2.21	  -1.22
nor	  1.93	  -0.07
ari	  1.91	  -1.65
cin	  1.58	  -0.48
det	  1.41	   1.48
min	  1.39	   0.27
pit	  0.91	  -1.97
sea	  0.83	  -2.05
was	  0.19	   1.01
phi	  0.14	   0.82
den	 -0.18	   1.51
chi	 -0.21	   0.60
tam	 -2.34	  -1.53
ten	 -2.85	   0.02
oak	 -3.48	   0.52
nyj	 -3.99	   0.95
mia	 -4.14	   0.86
bal	 -4.98	  -0.48
buf	 -5.59	   0.35
car	 -5.72	  -0.72
atl	 -5.76	  -0.26
ram	 -6.47	  -1.22
kan	 -7.35	   0.21
sfo	 -9.91	  -1.91

As you can see here, the 2007 Patriots topped the '98 Vikings for the best offense in NFL history. The '49ers offense was close to historically bad, too. The Steelers and Seahawks had the easiest schedules for offense, while the Lions and Broncos had the toughest schedules for scoring points.

Here are the defensive ratings:

	Def Rat	  Def SOS
ind	  5.39	   0.08
phi	  5.11	   2.18
sdg	  4.45	   0.51
pit	  4.30	  -0.58
was	  4.28	   1.97
nwe	  4.20	  -0.36
tam	  3.56	  -1.25
ten	  3.56	   0.43
gnb	  3.33	  -0.17
min	  2.40	   0.15
jax	  2.02	  -0.66
kan	  1.89	   1.14
dal	  1.66	   0.28
buf	  1.49	   1.92
chi 	  1.44	   1.50
sea	  0.93	  -2.57
nyg	  0.44	   0.69
nyj	  0.30	   0.80
car	 -0.09	  -0.09
bal	 -1.76	   0.55
sfo	 -2.03	  -0.96
oak	 -2.50	   0.69
hou	 -2.52	  -0.21
cle	 -3.28	  -1.09
den	 -3.77	   0.11
cin	 -3.96	  -1.59
mia	 -4.23	   1.39
nor	 -4.45	  -1.89
atl	 -4.85	  -0.66
det	 -4.96	   1.10
ari	 -5.85	  -2.60
ram	 -6.50	  -0.81

Of note, the Eagles defense played a pretty difficult schedule, while the Seahawks and Cardinals faced some really weak defenses. This sort of analysis is useful when looking at a team like Seattle. On the surface, it's easy to say the the Seahawks tied for 6th in the league in fewest points allowed. But when you play the schedule Seattle played, that's not so impressive. After adjustment, the Seahawks D falls to 16th best. I know these past couple of days seem like Seahawks bashing, but when you play a cupcake schedule, your raw stats aren't indicative of your actual ability.

This entry was posted on Tuesday, June 17th, 2008 at 4:25 am and is filed under History, Statgeekery. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.