2008 Luckiest Teams

Here's the final ranking of lucky and unlucky teams for 2008. I estimate team luck by using my efficiency regression model to calculate each team's expected wins--how many wins a team can normally expect, on average, given their actual performance in offensive and defensive running, passing, turnovers, and penalties. Expected wins are adjusted for average opponent strength.

The difference between the expected wins and actual wins is what I loosely estimate as team luck. For a brief introduction on the concept, see this last post on the subject. For a more thorough but general discussion, see this essay on NFL luck. The executive summary is that there are good and bad breaks for every team in every game, and often they'll roughly even out, but many times they won't. The bottom line is that a 16-game season is far too short for all the breaks to even out. With 32 teams in the league, some are going to be luckier than others.

Tennessee, New England, and the New York Jets top the list of lucky dogs in 2008, while San Diego, Kansas City, and New Orleans appear to be among the unluckiest.

Now, I don't claim this is all luck. Part of it could be game-day coaching. For those critics out there of Norv Turner or Andy Reid, you can point to this and say they managed to take teams with some of the most spectacular statistical performances and make mediocre records. You could also make the opposite claim about Jeff Fisher or Bill Belichick.

Also of note are the 0-16 Detroit Lions. They could have been expected to win 1 or 2 games given their stats this year.

You can click on the headers any column to sort the table. I've included a division column so you can see how teams lucked-out compared to their division-mates.

Rank	Team	Exp. W	Act. W	Luck	Div
1	TEN	10.5	13	+2.5	AS
2	NE	8.9	11	+2.1	AE
3	NYJ	7.0	9	+2.0	AE
4	SF	5.2	7	+1.8	NW
5	BUF	5.3	7	+1.7	AE
6	MIN	8.4	10	+1.6	NN
7	IND	10.6	12	+1.4	AS
8	NYG	11.0	12	+1.0	NE
9	HOU	7.0	8	+1.0	AS
10	CLE	3.1	4	+0.9	AN
11	MIA	10.1	11	+0.9	AE
12	ARI	8.2	9	+0.8	NW
13	DEN	7.5	8	+0.5	AW
14	BAL	10.5	11	+0.5	AN
15	PIT	11.9	12	+0.1	AN
16	JAX	4.9	5	0.1	AS
17	CHI	9.0	9	0.0	NN
18	OAK	5.1	5	-0.1	AW
19	TB	9.1	9	-0.1	NS
20	CIN	4.7	4.5	-0.2	AN
21	DAL	9.3	9	-0.3	NE
22	CAR	12.5	12	-0.5	NS
23	ATL	11.5	11	-0.5	NS
24	SEA	4.5	4	-0.5	NW
25	STL	2.8	2	-0.8	NW
26	DET	1.8	0	-1.8	NN
27	WAS	10.0	8	-2.0	NE
28	GB	8.5	6	-2.5	NN
29	PHI	12.1	9.5	-2.6	NE
30	NO	10.7	8	-2.7	NS
31	KC	4.9	2	-2.9	AW
32	SD	11.4	8	-3.4	AW

2008 Final Efficiency Rankings

The ratings are listed below in terms of generic win probability. The GWP is the probability a team would beat the league average team at a neutral site. Each team's opponent's average GWP is also listed, which can be considered to-date strength of schedule, and all ratings include adjustments for opponent strength.

Offensive rank (ORANK) is offensive generic win probability which is based on each team's offensive efficiency stats only. In other words, it's the team's GWP assuming it had a league-average defense. DRANK is is a team's generic win probability rank assuming it had a league-average offense.

GWP is based on a logistic regression model applied to current team stats. The model includes offensive and defensive passing and running efficiency, offensive turnover rates, and team penalty rates. A full explanation of the methodology can be found here. This year, however, I've made one important change based on research that strongly indicates that defensive interception rates are highly random and not consistent throughout the year. Accordingly, I've removed them from the model and updated the weights of the remaining stats.

RANK	TEAM	LAST WK	GWP	Opp GWP	O RANK	D RANK
1	CAR	1	0.79	0.55	4	6
2	PHI	2	0.77	0.52	11	2
3	PIT	3	0.75	0.53	20	1
4	ATL	4	0.73	0.54	3	17
5	SD	5	0.72	0.53	1	10
6	NYG	6	0.69	0.53	2	13
7	NO	8	0.68	0.55	5	19
8	IND	12	0.68	0.49	7	15
9	TEN	7	0.67	0.46	15	4
10	BAL	11	0.67	0.52	17	3
11	MIA	9	0.64	0.44	6	20
12	WAS	10	0.63	0.51	12	11
13	DAL	14	0.59	0.53	16	8
14	TB	13	0.58	0.55	19	9
15	CHI	15	0.57	0.51	22	7
16	NE	16	0.57	0.47	13	24
17	GB	17	0.54	0.51	14	18
18	MIN	19	0.53	0.52	23	5
19	ARI	18	0.52	0.50	9	23
20	DEN	20	0.48	0.50	8	27
21	HOU	22	0.45	0.50	10	28
22	NYJ	21	0.45	0.45	24	12
23	BUF	24	0.34	0.44	27	22
24	SEA	28	0.34	0.47	30	14
25	OAK	27	0.33	0.56	29	16
26	JAX	23	0.32	0.50	18	30
27	KC	26	0.31	0.53	21	26
28	CIN	29	0.30	0.55	32	21
29	SF	25	0.29	0.49	25	25
30	CLE	30	0.20	0.57	28	29
31	STL	31	0.18	0.52	26	31
32	DET	32	0.12	0.57	31	32

To-date efficiency stats below. As always, click on the headers to sort.

TEAM	OPASS	ORUN	OINTRATE	OFUMRATE	DPASS	DRUN	DINTRATE	PENRATE
ARI	7.1	3.5	0.024	0.028	6.5	4.0	0.025	0.39
ATL	7.4	4.4	0.025	0.015	6.0	4.9	0.018	0.29
BAL	6.0	4.0	0.028	0.025	5.1	3.6	0.049	0.40
BUF	5.9	4.2	0.031	0.034	6.3	4.3	0.020	0.28
CAR	7.3	4.8	0.029	0.014	5.7	4.4	0.022	0.32
CHI	5.5	3.9	0.027	0.016	5.9	3.4	0.035	0.29
CIN	4.3	3.6	0.029	0.027	6.3	3.9	0.024	0.30
CLE	4.6	3.9	0.041	0.024	7.1	4.5	0.052	0.35
DAL	6.6	4.3	0.037	0.032	5.3	4.2	0.016	0.49
DEN	7.1	4.8	0.029	0.019	7.0	5.0	0.012	0.37
DET	5.3	3.8	0.037	0.036	7.9	5.1	0.009	0.38
GB	6.6	4.1	0.024	0.023	6.0	4.6	0.042	0.49
HOU	7.3	4.3	0.036	0.028	6.9	4.5	0.025	0.34
IND	6.8	3.4	0.021	0.010	5.9	4.2	0.031	0.32
JAX	5.8	4.2	0.024	0.021	7.3	4.0	0.028	0.42
KC	5.4	4.8	0.030	0.022	7.0	5.0	0.025	0.32
MIA	7.0	4.2	0.014	0.017	6.2	4.2	0.033	0.34
MIN	6.0	4.5	0.038	0.028	6.0	3.3	0.023	0.35
NE	6.1	4.4	0.021	0.016	6.4	4.1	0.030	0.25
NO	7.7	4.0	0.028	0.018	6.4	4.2	0.029	0.39
NYG	6.1	5.0	0.020	0.017	5.8	4.0	0.034	0.42
NYJ	5.9	4.7	0.043	0.024	6.1	3.7	0.024	0.28
OAK	5.2	4.3	0.026	0.033	6.4	4.7	0.034	0.42
PHI	6.2	4.0	0.026	0.015	5.1	3.5	0.029	0.31
PIT	5.9	3.7	0.030	0.026	4.3	3.3	0.038	0.41
SD	7.7	4.1	0.023	0.017	6.3	4.0	0.025	0.38
SF	6.0	4.0	0.037	0.043	6.1	3.8	0.022	0.37
SEA	5.1	4.2	0.032	0.021	6.9	4.2	0.016	0.30
STL	5.2	4.0	0.037	0.023	7.3	4.9	0.027	0.37
TB	6.1	4.1	0.023	0.020	5.9	4.3	0.046	0.42
TEN	6.1	4.3	0.020	0.019	5.2	3.7	0.035	0.43
WAS	5.5	4.4	0.012	0.020	5.8	3.8	0.025	0.33
Avg	6.1	4.2	0.028	0.023	6.2	4.2	0.028	0.36