Predictions 2007 Week 9 and Accuracy Report

The predictions are based on yards per play on rushing and passing plays (sacks and sack yards included), sack rates, third down conversion rates, penalty yards per game, and fumble and interception rates. The models are trained on the 1996-2006 seasons. Linear regression predicts the final score margin (home team points - away team points). Logistic regression estimates the probability that the home team will win.


The predictions are based on yards per play on rushing and passing plays (sacks and sack yards included), sack rates, third down conversion rates, penalty yards per game, and fumble and interception rates. The models are trained on the 1996-2006 seasons. Linear regression predicts the final score margin (home team points - away team points). Logistic regression estimates the probability that the home team will win.

Predictions based on opponent-adjusted stats
Game	Predicted Final Score Margin	P(Home Team Wins)
CIN @ BUF	1.0045	52.7523
WAS @ NYJ	-3.2205	39.4645
SEA @ CLE	1.3537	53.5113
BAL @ PIT	7.5392	75.2282
NE @ IND	2.9047	61.2232
CAR @ TEN	5.5641	67.9738
GB @ KC	-0.9309	48.7180
HOU @ OAK	1.1558	52.2015
DAL @ PHI	-1.7509	43.1141
DEN @ DET	2.1942	55.9526
SD @ MIN	1.3128	57.3044
SF @ ATL	5.2070	66.1927
JAX @ NO	-0.4927	49.1553
ARI @ TB	7.8599	73.8157

Predictions based on unadjusted stats
Game	Predicted Final Score Margin	P(Home Team Wins)
CIN @ BUF	1.3931	55.0238
WAS @ NYJ	-2.9390	40.8522
SEA @ CLE	1.2344	53.1285
BAL @ PIT	7.5106	75.0971
NE @ IND	1.9491	58.4803
CAR @ TEN	5.0706	67.4653
GB @ KC	-0.2492	51.1181
HOU @ OAK	2.4255	54.9057
DAL @ PHI	-0.5842	46.7032
DEN @ DET	6.2572	66.6293
SD @ MIN	0.7142	53.3107
SF @ ATL	5.6014	67.5739
JAX @ NO	-0.0740	50.9851
ARI @ TB	6.0552	70.9135

Quick Summary of Accuracy
LAST WEEK
Linear regression, opponent adjusted: 6 out of 13
Logistic regression, opponent adjusted: 5 out of 13
Linear regression, unadjusted: 8 out of 13
Logistic regression, unadjusted: 8 out of 13

YEAR SO FAR
Linear regression, opponent adjusted: 66.6667%
Logistic regression, opponent adjusted: 65.4762%
Linear regression, unadjusted: 61.9048%
Logistic regression, unadjusted: 63.0952%

Full accuracy numbers after the jump...

OPPONENT ADJUSTED
Linear regression
Win prediction accuracy: 66.6667%
Mean absolute error: 11.2464 points
Correlation with result: 0.3735
% of games predicted as home team wins: 69.0476%
Logistic regression
Win prediction accuracy: 65.4762%
Correlation with result: 0.3749
% of games predicted as home team wins: 72.6190%
Win prediction accuracy when 20%≤P(home team wins)<30%: 100.0000
Win prediction accuracy when 30%≤P(home team wins)<40%: 88.8889
Win prediction accuracy when 40%≤P(home team wins)<50%: 58.3333
Win prediction accuracy when 50%≤P(home team wins)<60%: 50.0000
Win prediction accuracy when 60%≤P(home team wins)<70%: 76.4706
Win prediction accuracy when 70%≤P(home team wins)<80%: 58.8235
Win prediction accuracy when 80%≤P(home team wins)<90%: 80.0000

UNADJUSTED
Linear regression
Win prediction accuracy: 61.9048%
Mean absolute error: 11.1272 points
Correlation with result: 0.3770
% of games predicted as home team wins: 64.2857%
Logistic regression
Win prediction accuracy: 63.0952%
Correlation with result: 0.3777
% of games predicted as home team wins: 63.0952%
Win prediction accuracy when 10%≤P(home team wins)<20%: 100.0000
Win prediction accuracy when 20%≤P(home team wins)<30%: 100.0000
Win prediction accuracy when 30%≤P(home team wins)<40%: 66.6667
Win prediction accuracy when 40%≤P(home team wins)<50%: 50.0000
Win prediction accuracy when 50%≤P(home team wins)<60%: 42.8571
Win prediction accuracy when 60%≤P(home team wins)<70%: 70.5882
Win prediction accuracy when 70%≤P(home team wins)<80%: 78.5714
Win prediction accuracy when 80%≤P(home team wins)<90%: 42.8571
Win prediction accuracy when 90%≤P(home team wins)<100%: 100.0000

Read More......

Power Rankings 2007 Week 8

The power rankings for this site were developed in this article. The idea behind them is simple: if each team played one home game and one away game against every other team in the league, who would be the most successful?

The power rankings use logistic regression to predict the probability of winning. The score you see along with the rankings is the expected win total over a 16-game season based on the expected winning percentages over the 62 games (i.e. the sum of those probabilities).

San Diego is making a huge comeback to #6 after being bottom of the barrel to start. The Saints are climbing upwards from dead last towards mediocrity.

Power Rankings, Opponent-adjusted
Rank	Team	Expected Wins
1	NE	11.5856
2	IND	11.5305
3	DAL	11.0685
4	TB	10.0434
5	PIT	9.6449
6	SD	8.9480
7	TEN	8.8901
8	NYG	8.8737
9	WAS	8.8413
10	PHI	8.6632
11	SEA	8.6215
12	JAX	8.6040
13	GB	8.4589
14	MIN	8.3500
15	CIN	7.9932
16	DEN	7.8561
17	CLE	7.7744
18	ARI	7.6103
19	MIA	7.5862
20	CAR	7.3970
21	DET	7.3160
22	HOU	7.2904
23	BAL	6.9235
24	KC	6.9199
25	NO	6.8708
26	ATL	6.7046
27	BUF	6.6202
28	CHI	6.1950
29	OAK	6.1287
30	STL	6.0256
31	NYJ	5.4028
32	SF	5.2618

Read More......

The Value of Homefield Advantage 2007 Week 8

One of the things I've learned in my football research is that the value of home-field advantage varies pretty widely from year to year, especially with interconference games. Because prediction systems tend to have a big bias towards the home team, this can have a large impact on accuracy. So throughout the season, I'll be keeping track of home team winning percentage and average final score margin (home team points - away team points) for interconference, interdivision, and intradivision matchups. If you're interested in that sort of thing, it can help you with betting on the spread (hint).

Home field advantage dropped off 3% after this week, with interconference HFA taking the biggest hit. Only 41% of divisional games have been won by the home team so far, dropping even further from last week. Bizarre. HFA is still strong in interdivisional games, though (good news for Indy).

All Games
Home Team Win %: 55.1724%
Avg. Final Score Margin: 1.6983

Interconference
Home Team Win %: 59.3750%
Avg. Final Score Margin: 3.3125

Interdivision, Intraconference
Home Team Win %: 65.8537%
Avg. Final Score Margin: 4.0976

Intradivsion
Home Team Win %: 41.8605%
Avg. Final Score Margin: -1.7907

Read More......

Projected Final Standings 2007 Week 8

Using the projected win probabilities from the logistic regression power rankings, I estimated which games each team would win on the rest of their respective schedules. And then I summed the projected wins with the actual wins so far to get their projected win totals. The teams are sorted by division.

Projected Final Standings
Team	Projected Win Total
AFC East
BUF	5
MIA	4
NE	15
NYJ	2
AFC North
BAL	6
CIN	7
CLE	9
PIT	13
AFC South
HOU	6
IND	16
JAX	10
TEN	11
AFC West
DEN	8
KC	6
OAK	4
SD	9
NFC East
DAL	15
NYG	11
PHI	8
WAS	8
NFC North
CHI	4
DET	8
GB	13
MIN	8
NFC South
ATL	3
CAR	7
NO	5
TB	12
NFC West
ARI	8
STL	1
SF	3
SEA	11

Read More......

Stats (Raw and VOLA) 2007 Week 8

This is the data I use to make my predictions and power rankings. Below are the tables for the raw stats and the values over league average for all of the inputs I use. Rush and pass stats are yards per play. See for yourself where your team's strengths and weaknesses are.

Rush offense, Unadjusted (League Avg = 4.0915)
Rank	Team	VOLA (%)	Actual Stat
1	MIN	26.5110	5.1762
2	MIA	18.6030	4.8526
3	DAL	17.1880	4.7947
4	PIT	16.3560	4.7607
5	NYG	13.6460	4.6498
6	CLE	11.7500	4.5722
7	DEN	11.0030	4.5417
8	PHI	10.9750	4.5405
9	IND	8.1130	4.4234
10	JAX	8.0272	4.4199
11	OAK	7.5625	4.4009
12	CAR	7.1371	4.3835
13	SD	3.0099	4.2146
14	NE	2.4824	4.1930
15	DET	2.2962	4.1854
16	TB	1.4421	4.1505
17	SF	1.0447	4.1342
18	TEN	0.4269	4.1089
19	BAL	-4.4691	3.9086
20	CIN	-4.6238	3.9023
21	ATL	-4.6350	3.9018
22	ARI	-6.8669	3.8105
23	NO	-11.8480	3.6067
24	BUF	-12.0120	3.6000
25	SEA	-13.7990	3.5269
26	WAS	-14.0470	3.5168
27	NYJ	-14.9830	3.4785
28	STL	-15.4860	3.4579
29	GB	-17.5940	3.3716
30	KC	-20.1500	3.2670
31	HOU	-20.9040	3.2362
32	CHI	-22.8890	3.1550

Rush defense, Unadjusted (League Avg = 4.0915)
Rank	Team	VOLA (%)	Actual Stat
1	BAL	28.9370	2.9075
2	MIN	28.8620	2.9106
3	TEN	17.2340	3.3864
4	WAS	11.1740	3.6343
5	NO	11.1590	3.6349
6	DAL	10.8710	3.6467
7	PHI	10.5710	3.6590
8	SD	9.6683	3.6959
9	PIT	7.0216	3.8042
10	GB	6.9621	3.8066
11	TB	5.6463	3.8605
12	CAR	4.9915	3.8873
13	SF	4.9883	3.8874
14	DET	4.9793	3.8878
15	SEA	2.7532	3.9788
16	KC	2.1073	4.0053
17	NYJ	0.9447	4.0528
18	IND	0.6506	4.0649
19	STL	0.0228	4.0906
20	NYG	-0.0202	4.0923
21	ARI	-2.4386	4.1913
22	JAX	-3.0596	4.2167
23	ATL	-3.9918	4.2548
24	NE	-4.0618	4.2577
25	MIA	-9.7282	4.4895
26	HOU	-11.2530	4.5519
27	CHI	-12.2360	4.5921
28	BUF	-14.5270	4.6859
29	CLE	-14.6850	4.6923
30	CIN	-14.8850	4.7005
31	DEN	-20.8530	4.9447
32	OAK	-28.6240	5.2626

Pass offense, Unadjusted (League Avg = 6.1566)
Rank	Team	VOLA (%)	Actual Stat
1	NE	40.4620	8.6477
2	DAL	23.5100	7.6040
3	IND	23.0100	7.5732
4	CLE	17.0600	7.2069
5	DEN	15.7120	7.1239
6	HOU	13.5380	6.9901
7	CIN	13.2090	6.9698
8	TB	12.6600	6.9360
9	GB	12.1030	6.9017
10	SD	12.0750	6.9000
11	PIT	10.4190	6.7980
12	SEA	4.3902	6.4269
13	ARI	3.4606	6.3696
14	PHI	-0.5435	6.1231
15	DET	-0.7970	6.1075
16	NO	-4.6719	5.8690
17	KC	-4.9189	5.8538
18	WAS	-5.1002	5.8426
19	JAX	-5.8391	5.7971
20	NYG	-6.5893	5.7509
21	NYJ	-6.6495	5.7472
22	MIA	-7.4386	5.6986
23	CHI	-10.1990	5.5287
24	BUF	-12.3410	5.3968
25	OAK	-12.3940	5.3935
26	ATL	-12.7860	5.3694
27	CAR	-12.8980	5.3625
28	TEN	-13.0810	5.3512
29	BAL	-13.2390	5.3415
30	STL	-16.3650	5.1491
31	MIN	-20.0710	4.9209
32	SF	-38.0370	3.8148

Pass defense, Unadjusted (League Avg = 6.1566)
Rank	Team	VOLA (%)	Actual Stat
1	IND	22.2760	4.7852
2	NE	17.2470	5.0948
3	PIT	15.8330	5.1818
4	WAS	13.8850	5.3018
5	NYG	13.5910	5.3199
6	TB	12.8050	5.3682
7	TEN	10.4010	5.5162
8	ARI	9.9744	5.5425
9	KC	9.5141	5.5708
10	SEA	9.0772	5.5977
11	DAL	9.0157	5.6015
12	PHI	5.8688	5.7953
13	OAK	2.7767	5.9856
14	GB	1.2989	6.0766
15	SF	-1.4679	6.2470
16	DET	-1.9684	6.2778
17	JAX	-2.1163	6.2869
18	BAL	-2.2995	6.2982
19	HOU	-3.6175	6.3793
20	SD	-3.8177	6.3916
21	CAR	-4.1370	6.4113
22	CHI	-5.9563	6.5233
23	BUF	-7.4567	6.6157
24	MIN	-9.2596	6.7267
25	CLE	-10.3230	6.7921
26	STL	-10.4780	6.8017
27	ATL	-11.3170	6.8533
28	CIN	-13.8970	7.0122
29	NO	-16.3950	7.1660
30	MIA	-17.0760	7.2079
31	DEN	-19.1440	7.3352
32	NYJ	-28.6670	7.9215

Sack rate made, Unadjusted (League Avg = 6.0561%)
Rank	Team	VOLA (%)	Actual Stat
1	NYG	55.6710	9.4276
2	PHI	49.5200	9.0551
3	CHI	47.9590	8.9606
4	SEA	42.7750	8.6466
5	KC	40.3880	8.5021
6	PIT	29.6420	7.8513
7	DEN	29.1460	7.8212
8	JAX	28.5790	7.7869
9	NE	27.4630	7.7193
10	DAL	13.8780	6.8966
11	ARI	13.6470	6.8826
12	BAL	13.6160	6.8807
13	DET	8.9349	6.5972
14	GB	7.5510	6.5134
15	SD	6.7331	6.4639
16	TB	2.4015	6.2015
17	MIN	-0.9265	6.0000
18	WAS	-7.2997	5.6140
19	OAK	-13.0930	5.2632
20	TEN	-16.5450	5.0541
21	HOU	-17.7550	4.9808
22	IND	-18.1210	4.9587
23	STL	-18.1210	4.9587
24	MIA	-18.2560	4.9505
25	CIN	-19.4520	4.8781
26	SF	-19.7790	4.8583
27	NO	-20.6840	4.8035
28	ATL	-33.9510	4.0000
29	NYJ	-45.4140	3.3058
30	BUF	-50.7100	2.9851
31	CLE	-58.5710	2.5090
32	CAR	-73.3670	1.6129

Sack rate allowed, Unadjusted (League Avg = 6.0561%)
Rank	Team	VOLA (%)	Actual Stat
1	NO	77.2240	1.3793
2	IND	65.4560	2.0920
3	NE	52.9900	2.8470
4	ARI	48.6000	3.1128
5	BAL	47.6720	3.1690
6	NYG	45.5640	3.2967
7	CIN	37.6900	3.7736
8	GB	30.4750	4.2105
9	HOU	28.9210	4.3046
10	DAL	27.3460	4.4000
11	MIA	20.8320	4.7945
12	TB	20.7410	4.8000
13	DEN	19.6310	4.8672
14	SD	17.4390	5.0000
15	CAR	17.4390	5.0000
16	TEN	11.3980	5.3658
17	WAS	8.2653	5.5556
18	CLE	7.4745	5.6034
19	SEA	-4.4253	6.3241
20	CHI	-10.4320	6.6879
21	NYJ	-22.7680	7.4350
22	PIT	-27.0170	7.6923
23	STL	-28.2010	7.7640
24	KC	-30.5320	7.9052
25	BUF	-39.7860	8.4656
26	MIN	-45.9220	8.8372
27	JAX	-51.5620	9.1788
28	ATL	-54.0320	9.3284
29	PHI	-66.3550	10.0746
30	OAK	-75.8250	10.6482
31	SF	-76.6740	10.6996
32	DET	-95.3060	11.8279

Third down % converted, Unadjusted (League Avg = 40.9772%)
Rank	Team	VOLA (%)	Actual Stat
1	PIT	34.4700	55.1020
2	IND	31.6160	53.9325
3	NE	19.1810	48.8370
4	DEN	17.5000	48.1482
5	NO	14.6980	47.0000
6	DAL	14.0610	46.7390
7	CLE	12.2010	45.9768
8	HOU	11.1460	45.5445
9	TEN	6.7667	43.7500
10	NYG	6.6186	43.6893
11	NYJ	4.5878	42.8572
12	SD	4.1626	42.6829
13	JAX	1.6826	41.6667
14	PHI	1.4812	41.5842
15	OAK	0.9004	41.3462
16	ATL	0.3521	41.1215
17	BAL	0.2300	41.0714
18	CIN	-0.5770	40.7407
19	GB	-0.7757	40.6593
20	TB	-1.3463	40.4255
21	CAR	-2.8586	39.8058
22	MIA	-3.4016	39.5833
23	ARI	-5.9436	38.5417
24	CHI	-9.2956	37.1681
25	WAS	-12.6600	35.7895
26	STL	-12.6840	35.7797
27	KC	-14.5870	34.9999
28	SEA	-15.1170	34.7827
29	BUF	-21.5590	32.1429
30	MIN	-24.5240	30.9280
31	SF	-25.2940	30.6124
32	DET	-27.6920	29.6298

Third down % allowed, Unadjusted (League Avg = 40.9772%)
Rank	Team	VOLA (%)	Actual Stat
1	NE	29.8740	28.7357
2	BAL	19.5190	32.9789
3	KC	16.9230	34.0426
4	GB	16.9230	34.0426
5	WAS	15.2290	34.7368
6	CHI	11.4550	36.2833
7	PHI	9.7059	37.0000
8	TEN	8.1577	37.6344
9	ATL	8.1268	37.6471
10	STL	6.3288	38.3838
11	OAK	4.3974	39.1753
12	JAX	3.5198	39.5349
13	SEA	2.8586	39.8058
14	DAL	1.8542	40.2174
15	NYG	0.5770	40.7407
16	SD	0.0326	40.9639
17	ARI	-0.0556	41.0000
18	TB	-3.0851	42.2414
19	SF	-4.2493	42.7184
20	CIN	-5.3801	43.1818
21	CLE	-5.6660	43.2990
22	MIN	-6.3137	43.5644
23	HOU	-7.3768	44.0000
24	CAR	-8.1819	44.3299
25	PIT	-8.4614	44.4444
26	NO	-10.2110	45.1614
27	BUF	-11.4090	45.6523
28	IND	-12.8350	46.2366
29	DET	-13.2140	46.3919
30	DEN	-17.7130	48.2355
31	NYJ	-18.2450	48.4535
32	MIA	-22.0190	50.0000

Int. Rate Given, Unadjusted (League Avg = 2.8921%)
Rank	Team	VOLA (%)	Actual Stat
1	PHI	74.1960	0.7463
2	JAX	66.5920	0.9662
3	NE	63.0850	1.0676
4	IND	56.5980	1.2552
5	BAL	51.3000	1.4085
6	ATL	48.3930	1.4925
7	TB	44.6770	1.6000
8	CAR	42.3720	1.6667
9	GB	39.3390	1.7544
10	SEA	17.9990	2.3716
11	SF	14.6250	2.4691
12	KC	4.3326	2.7668
13	WAS	3.9530	2.7778
14	MIN	3.5063	2.7907
15	DET	0.8547	2.8674
16	PIT	0.2589	2.8846
17	TEN	-1.2008	2.9268
18	BUF	-9.7680	3.1746
19	NYG	-13.9900	3.2967
20	CIN	-17.4310	3.3962
21	NO	-19.2310	3.4483
22	SD	-21.0190	3.5000
23	DEN	-22.3960	3.5398
24	DAL	-24.4770	3.6000
25	MIA	-30.2560	3.7671
26	CLE	-34.1350	3.8793
27	ARI	-34.5410	3.8911
28	HOU	-37.3920	3.9735
29	NYJ	-41.3930	4.0892
30	OAK	-44.0710	4.1667
31	STL	-71.8110	4.9689
32	CHI	-76.1880	5.0955

Int. Rate Taken, Unadjusted (League Avg = 2.8921%)
Rank	Team	VOLA (%)	Actual Stat
1	OAK	65.4400	4.7847
2	BAL	58.6100	4.5872
3	DET	56.0760	4.5139
4	SD	44.6180	4.1825
5	BUF	41.9200	4.1045
6	TEN	37.3090	3.9711
7	NE	33.4550	3.8597
8	DAL	32.4790	3.8314
9	IND	28.5920	3.7190
10	DEN	15.9000	3.3519
11	JAX	13.3670	3.2787
12	CIN	12.4450	3.2520
13	KC	11.9900	3.2389
14	ATL	7.5726	3.1111
15	SEA	3.9907	3.0075
16	WAS	-2.9420	2.8070
17	TB	-6.1866	2.7132
18	NYJ	-14.2720	2.4793
19	PIT	-14.2720	2.4793
20	ARI	-16.0070	2.4292
21	NYG	-18.5060	2.3569
22	MIN	-19.3210	2.3333
23	GB	-20.5130	2.2988
24	CLE	-25.6410	2.1505
25	STL	-28.5600	2.0661
26	CAR	-30.2880	2.0161
27	MIA	-31.5310	1.9802
28	PHI	-31.9350	1.9685
29	SF	-44.0050	1.6194
30	HOU	-47.0090	1.5326
31	CHI	-50.4270	1.4337
32	NO	-54.7030	1.3100

Fum. Rate Given, Unadjusted (League Avg = 3.0151%)
Rank	Team	VOLA (%)	Actual Stat
1	SEA	52.0710	1.4451
2	BUF	48.8170	1.5432
3	IND	47.6320	1.5789
4	NE	36.2180	1.9231
5	ATL	31.7160	2.0588
6	SD	31.5140	2.0649
7	NYJ	31.2610	2.0725
8	PHI	25.6770	2.2409
9	NYG	24.6210	2.2727
10	DAL	24.4060	2.2792
11	CIN	23.7550	2.2988
12	PIT	20.1870	2.4064
13	NO	19.7580	2.4194
14	MIA	19.1060	2.4390
15	STL	12.9480	2.6247
16	TB	11.3190	2.6738
17	JAX	8.8828	2.7473
18	MIN	8.4356	2.7607
19	KC	3.5853	2.9070
20	BAL	-4.4619	3.1496
21	TEN	-11.7010	3.3679
22	CLE	-15.4540	3.4810
23	DEN	-15.6980	3.4884
24	CAR	-21.7980	3.6723
25	GB	-26.4420	3.8123
26	HOU	-30.0650	3.9216
27	ARI	-35.3740	4.0816
28	CHI	-43.8350	4.3367
29	DET	-60.6360	4.8433
30	SF	-73.3450	5.2265
31	WAS	-75.0730	5.2786
32	OAK	-94.0110	5.8496

Fum. Rate Taken, Unadjusted (League Avg = 3.0151%)
Rank	Team	VOLA (%)	Actual Stat
1	DET	81.5090	5.4726
2	SEA	48.2310	4.4693
3	TEN	43.7220	4.3333
4	PIT	36.7700	4.1237
5	SD	34.5890	4.0580
6	IND	33.4290	4.0230
7	DAL	32.2600	3.9877
8	NYG	31.9630	3.9788
9	WAS	29.7020	3.9106
10	MIN	28.5530	3.8760
11	CAR	21.7980	3.6723
12	HOU	19.9830	3.6176
13	GB	17.7510	3.5503
14	CHI	1.6903	3.0660
15	NO	-0.1004	3.0120
16	STL	-1.7284	2.9630
17	MIA	-2.6895	2.9340
18	NE	-3.0214	2.9240
19	TB	-6.5728	2.8169
20	CIN	-11.3190	2.6738
21	BUF	-18.4430	2.4590
22	JAX	-20.7960	2.3881
23	ARI	-21.4990	2.3669
24	KC	-23.3140	2.3121
25	BAL	-23.3770	2.3102
26	ATL	-25.6770	2.2409
27	DEN	-26.9050	2.2039
28	CLE	-38.7420	1.8470
29	PHI	-39.6970	1.8182
30	SF	-48.4460	1.5544
31	NYJ	-69.0750	0.9324
32	OAK	-69.5720	0.9174

Rush offense, Adjusted (League Avg = 4.0915)
Rank	Team	VOLA (%)	Actual Stat
1	MIN	27.6570	5.2231
2	DAL	18.4120	4.8448
3	PHI	16.8250	4.7799
4	NYG	16.6590	4.7731
5	MIA	12.2330	4.5920
6	CLE	8.8916	4.4553
7	PIT	8.2679	4.4298
8	IND	8.1853	4.4264
9	SF	7.3020	4.3902
10	CAR	7.1401	4.3836
11	DEN	5.8070	4.3291
12	TB	5.2702	4.3071
13	ATL	4.6923	4.2835
14	JAX	4.4260	4.2726
15	DET	1.8619	4.1677
16	OAK	1.6173	4.1577
17	ARI	0.7566	4.1224
18	NE	0.0123	4.0920
19	CIN	-2.4822	3.9899
20	TEN	-4.4548	3.9092
21	BUF	-7.2801	3.7936
22	SD	-8.4227	3.7469
23	NO	-8.5986	3.7397
24	BAL	-9.5323	3.7015
25	STL	-10.5160	3.6612
26	SEA	-12.1910	3.5927
27	WAS	-13.1040	3.5553
28	CHI	-13.6920	3.5313
29	NYJ	-14.8960	3.4820
30	GB	-16.8820	3.4008
31	HOU	-18.7450	3.3245
32	KC	-23.6440	3.1241

Rush defense, Adjusted (League Avg = 4.0915)
Rank	Team	VOLA (%)	Actual Stat
1	MIN	25.3690	3.0535
2	BAL	24.0290	3.1083
3	TEN	16.9810	3.3967
4	WAS	13.9970	3.5188
5	DAL	12.1950	3.5925
6	NO	11.4570	3.6227
7	GB	10.3530	3.6679
8	PIT	4.2762	3.9165
9	DET	4.0629	3.9252
10	PHI	3.8694	3.9332
11	SF	3.8056	3.9358
12	TB	2.8744	3.9739
13	STL	2.6908	3.9814
14	NYJ	2.5803	3.9859
15	IND	2.5023	3.9891
16	SEA	0.8834	4.0553
17	NYG	0.6743	4.0639
18	ATL	0.3469	4.0773
19	KC	-0.3663	4.1065
20	NE	-1.4436	4.1505
21	CAR	-1.7740	4.1641
22	SD	-1.8450	4.1670
23	JAX	-3.6379	4.2403
24	CHI	-5.7925	4.3285
25	ARI	-6.6320	4.3628
26	HOU	-7.5381	4.3999
27	MIA	-8.9423	4.4574
28	CLE	-10.3910	4.5166
29	BUF	-11.4420	4.5596
30	CIN	-16.8010	4.7789
31	DEN	-17.7210	4.8165
32	OAK	-25.3190	5.1274

Pass offense, Adjusted (League Avg = 6.1566)
Rank	Team	VOLA (%)	Actual Stat
1	NE	34.0030	8.2500
2	DAL	21.7780	7.4974
3	IND	21.3440	7.4707
4	DEN	19.9300	7.3836
5	CIN	16.8820	7.1959
6	CLE	16.4390	7.1687
7	TB	14.7140	7.0625
8	HOU	14.6060	7.0558
9	SD	12.2420	6.9103
10	GB	10.4230	6.7983
11	ARI	8.1513	6.6584
12	PIT	5.5304	6.4971
13	SEA	3.2866	6.3589
14	NO	1.0500	6.2212
15	DET	-0.3448	6.1354
16	WAS	-0.3778	6.1333
17	JAX	-3.2676	5.9554
18	PHI	-3.8074	5.9222
19	MIA	-5.7332	5.8036
20	NYG	-6.8210	5.7367
21	NYJ	-7.1053	5.7191
22	KC	-9.5986	5.5656
23	CHI	-9.7913	5.5538
24	TEN	-10.7360	5.4956
25	CAR	-10.8750	5.4871
26	OAK	-13.2920	5.3383
27	ATL	-14.9500	5.2362
28	STL	-14.9500	5.2362
29	BUF	-17.6510	5.0699
30	BAL	-18.9090	4.9924
31	MIN	-19.7160	4.9428
32	SF	-35.0200	4.0006

Pass defense, Adjusted (League Avg = 6.1566)
Rank	Team	VOLA (%)	Actual Stat
1	IND	21.7450	4.8178
2	NE	21.0350	4.8616
3	WAS	19.0080	4.9863
4	TEN	14.1620	5.2847
5	PIT	12.7630	5.3708
6	TB	10.4560	5.5129
7	NYG	9.7971	5.5534
8	KC	8.8924	5.6091
9	SEA	8.8326	5.6128
10	DAL	7.9650	5.6662
11	OAK	7.3671	5.7030
12	JAX	4.1539	5.9009
13	SD	3.6302	5.9331
14	BUF	1.7223	6.0506
15	PHI	0.3386	6.1357
16	ARI	-0.0603	6.1603
17	GB	-1.4480	6.2457
18	CHI	-2.3288	6.3000
19	MIA	-2.7920	6.3285
20	CAR	-3.7538	6.3877
21	SF	-7.7133	6.6315
22	CIN	-8.3484	6.6706
23	BAL	-8.5472	6.6828
24	DET	-8.6210	6.6874
25	HOU	-8.6669	6.6902
26	MIN	-9.1385	6.7192
27	STL	-9.4656	6.7394
28	DEN	-10.2060	6.7849
29	CLE	-11.5130	6.8654
30	ATL	-18.2170	7.2781
31	NO	-23.6570	7.6131
32	NYJ	-30.0900	8.0091

Sack rate made, Adjusted (League Avg = 6.0561%)
Rank	Team	VOLA (%)	Actual Stat
1	JAX	45.3020	8.7997
2	NE	37.8730	8.3497
3	TB	36.6540	8.2759
4	KC	36.1370	8.2446
5	PIT	34.6270	8.1532
6	SEA	28.7230	7.7956
7	DAL	26.5530	7.6642
8	PHI	25.9800	7.6295
9	ARI	23.8190	7.4986
10	CHI	17.6240	7.1234
11	GB	15.4780	6.9935
12	NYG	12.7450	6.8280
13	IND	12.4650	6.8110
14	TEN	10.0170	6.6628
15	SD	9.5176	6.6325
16	MIA	4.6211	6.3360
17	WAS	1.4672	6.1450
18	BAL	-1.0970	5.9897
19	DEN	-5.2377	5.7389
20	STL	-5.9148	5.6979
21	DET	-8.7839	5.5241
22	HOU	-8.9739	5.5126
23	OAK	-13.8120	5.2196
24	CIN	-19.5580	4.8717
25	SF	-20.0960	4.8391
26	MIN	-20.8250	4.7949
27	ATL	-30.1590	4.2296
28	NO	-34.5350	3.9646
29	BUF	-42.5280	3.4806
30	NYJ	-53.4820	2.8172
31	CLE	-59.5420	2.4502
32	CAR	-64.5770	2.1453

Sack rate allowed, Adjusted (League Avg = 6.0561%)
Rank	Team	VOLA (%)	Actual Stat
1	NO	75.1030	1.5078
2	IND	64.2960	2.1623
3	NE	48.0590	3.1456
4	GB	43.1720	3.4416
5	NYG	42.2500	3.4974
6	BAL	39.1020	3.6881
7	CIN	36.6890	3.8342
8	DAL	35.8550	3.8847
9	SD	32.5560	4.0845
10	TB	32.2730	4.1016
11	HOU	23.7910	4.6153
12	WAS	20.3200	4.8255
13	CLE	16.0270	5.0855
14	DEN	15.2600	5.1319
15	ARI	13.3970	5.2448
16	TEN	6.0312	5.6909
17	MIA	3.3777	5.8516
18	CHI	2.9055	5.8802
19	CAR	2.7155	5.8917
20	SEA	-15.1830	6.9756
21	MIN	-15.9870	7.0243
22	KC	-31.0300	7.9353
23	PIT	-34.1250	8.1228
24	NYJ	-34.5140	8.1463
25	BUF	-40.6060	8.5153
26	STL	-40.7240	8.5224
27	PHI	-48.9230	9.0189
28	SF	-51.4400	9.1714
29	DET	-62.4000	9.8351
30	ATL	-62.8740	9.8638
31	JAX	-63.1900	9.8830
32	OAK	-90.6510	11.5460

Third down % converted, Adjusted (League Avg = 40.9772%)
Rank	Team	VOLA (%)	Actual Stat
1	PIT	26.5840	51.8706
2	IND	26.3060	51.7567
3	NE	16.1880	47.6106
4	DEN	16.0980	47.5737
5	DAL	15.5390	47.3446
6	SD	14.6850	46.9947
7	CLE	14.6050	46.9619
8	NO	13.1590	46.3694
9	HOU	12.8130	46.2276
10	NYG	11.4110	45.6531
11	NYJ	8.6937	44.5396
12	PHI	4.3509	42.7601
13	TEN	4.0889	42.6527
14	JAX	2.3951	41.9586
15	GB	1.8497	41.7352
16	MIA	0.4802	41.1740
17	CIN	-2.2681	40.0478
18	ARI	-2.5506	39.9320
19	ATL	-3.3325	39.6116
20	BAL	-4.5159	39.1267
21	OAK	-4.8691	38.9820
22	TB	-4.9265	38.9585
23	CAR	-6.9549	38.1273
24	CHI	-8.8911	37.3339
25	WAS	-11.3680	36.3189
26	STL	-12.2670	35.9505
27	KC	-14.2200	35.1502
28	SEA	-17.7550	33.7017
29	MIN	-19.0600	33.1669
30	BUF	-20.8090	32.4503
31	DET	-23.6720	31.2771
32	SF	-26.0560	30.3002

Third down % allowed, Adjusted (League Avg = 40.9772%)
Rank	Team	VOLA (%)	Actual Stat
1	NE	28.8210	29.1672
2	WAS	16.9150	34.0459
3	KC	15.8260	34.4921
4	TEN	15.2070	34.7458
5	BAL	14.4770	35.0449
6	GB	13.5660	35.4182
7	ATL	10.3850	36.7217
8	JAX	9.6064	37.0408
9	SEA	5.9498	38.5391
10	STL	4.9667	38.9420
11	SD	3.5422	39.5257
12	BUF	3.3795	39.5924
13	CHI	3.0146	39.7419
14	OAK	1.5944	40.3239
15	TB	1.2711	40.4563
16	DAL	0.7164	40.6836
17	CIN	0.0135	40.9716
18	PHI	-0.3668	41.1275
19	SF	-1.5339	41.6057
20	NYG	-1.9522	41.7772
21	HOU	-3.3873	42.3652
22	CLE	-3.3956	42.3686
23	CAR	-3.9346	42.5895
24	ARI	-5.5655	43.2578
25	IND	-6.6908	43.7189
26	DEN	-8.9217	44.6331
27	MIN	-11.7440	45.7896
28	PIT	-15.4080	47.2910
29	MIA	-16.6060	47.7819
30	NO	-18.0940	48.3916
31	NYJ	-21.2500	49.6849
32	DET	-25.1940	51.3010

Int. Rate Given, Adjusted (League Avg = 2.8921%)
Rank	Team	VOLA (%)	Actual Stat
1	JAX	74.0200	0.7514
2	PHI	68.7190	0.9047
3	NE	62.5770	1.0823
4	IND	61.2810	1.1198
5	TB	52.6440	1.3696
6	ATL	49.2250	1.4685
7	BAL	44.9300	1.5927
8	MIN	23.6010	2.2095
9	GB	17.8150	2.3769
10	CAR	14.4460	2.4743
11	SF	12.1440	2.5409
12	PIT	5.2338	2.7407
13	BUF	2.4820	2.8203
14	DEN	-0.9417	2.9193
15	DET	-4.8105	3.0312
16	CLE	-8.9414	3.1507
17	OAK	-10.0380	3.1824
18	NO	-11.2780	3.2183
19	HOU	-11.5350	3.2257
20	SEA	-13.9590	3.2958
21	TEN	-17.1310	3.3875
22	CIN	-18.2650	3.4203
23	KC	-18.3670	3.4233
24	WAS	-21.4700	3.5130
25	DAL	-23.3220	3.5666
26	SD	-23.8590	3.5821
27	MIA	-26.9490	3.6715
28	NYJ	-30.0710	3.7618
29	NYG	-31.1430	3.7928
30	CHI	-42.7550	4.1286
31	STL	-60.0690	4.6294
32	ARI	-84.2800	5.3296

Int. Rate Taken, Adjusted (League Avg = 2.8921%)
Rank	Team	VOLA (%)	Actual Stat
1	IND	92.5960	5.5701
2	CIN	64.5930	4.7602
3	JAX	60.2020	4.6332
4	TEN	54.9340	4.4808
5	OAK	41.4410	4.0906
6	SD	37.8300	3.9862
7	NYJ	17.0760	3.3860
8	DET	14.1350	3.3009
9	BAL	13.4460	3.2810
10	BUF	11.8000	3.2334
11	NE	10.5920	3.1984
12	GB	8.9514	3.1510
13	WAS	3.7953	3.0019
14	TB	2.0187	2.9505
15	ATL	1.3333	2.9307
16	DEN	-3.4451	2.7925
17	DAL	-5.3582	2.7371
18	MIA	-5.5281	2.7322
19	MIN	-7.3750	2.6788
20	SEA	-15.0510	2.4568
21	KC	-17.2270	2.3939
22	NYG	-19.4810	2.3287
23	STL	-20.5190	2.2987
24	PIT	-21.1890	2.2793
25	CLE	-27.2030	2.1054
26	PHI	-28.0850	2.0799
27	ARI	-32.9120	1.9403
28	HOU	-39.1450	1.7600
29	NO	-40.4660	1.7218
30	CAR	-45.5240	1.5755
31	CHI	-46.4190	1.5496
32	SF	-49.8380	1.4507

Fum. Rate Given, Adjusted (League Avg = 3.0151%)
Rank	Team	VOLA (%)	Actual Stat
1	IND	52.5640	1.4302
2	PHI	45.8230	1.6335
3	SEA	45.4620	1.6444
4	ATL	40.3120	1.7996
5	MIA	35.4740	1.9455
6	TB	33.5000	2.0050
7	NE	31.0580	2.0787
8	DAL	28.2910	2.1621
9	BUF	27.1140	2.1976
10	SD	26.7560	2.2084
11	NO	22.4800	2.3373
12	NYJ	20.9410	2.3837
13	CIN	20.3410	2.4018
14	MIN	19.1650	2.4372
15	JAX	10.2760	2.7052
16	NYG	8.8114	2.7494
17	KC	8.3497	2.7633
18	STL	-3.9565	3.1344
19	PIT	-4.1428	3.1400
20	CHI	-10.5330	3.3327
21	CAR	-11.9070	3.3741
22	GB	-18.3890	3.5695
23	HOU	-25.9100	3.7963
24	DEN	-26.0830	3.8015
25	ARI	-26.3870	3.8107
26	TEN	-34.4150	4.0527
27	CLE	-34.9530	4.0689
28	BAL	-41.5950	4.2692
29	WAS	-48.1520	4.4669
30	SF	-56.4320	4.7165
31	DET	-62.1260	4.8882
32	OAK	-91.1360	5.7629

Fum. Rate Taken, Adjusted (League Avg = 3.0151%)
Rank	Team	VOLA (%)	Actual Stat
1	DAL	61.5090	4.8696
2	SEA	49.9570	4.5213
3	CAR	40.7650	4.2442
4	DET	38.0710	4.1629
5	PIT	36.6130	4.1190
6	NYG	32.7870	4.0036
7	TEN	32.4730	3.9942
8	HOU	25.9700	3.7981
9	SD	24.1520	3.7433
10	IND	23.6720	3.7288
11	NO	20.6830	3.6387
12	GB	19.1030	3.5910
13	MIN	15.8210	3.4921
14	NE	12.4910	3.3917
15	WAS	11.1760	3.3520
16	TB	10.6560	3.3364
17	BUF	2.9144	3.1029
18	ARI	-1.4546	2.9712
19	MIA	-7.2961	2.7951
20	CHI	-9.4795	2.7293
21	CIN	-10.8950	2.6866
22	STL	-13.3000	2.6141
23	BAL	-18.9070	2.4450
24	JAX	-20.7610	2.3891
25	KC	-25.0500	2.2598
26	ATL	-29.2700	2.1326
27	DEN	-29.2910	2.1319
28	SF	-42.5680	1.7316
29	CLE	-44.6840	1.6678
30	NYJ	-55.1170	1.3533
31	PHI	-60.5530	1.1894
32	OAK	-73.3680	0.8030

Read More......

The Key to Good Predictions (though not yet a solution)

(Credit goes to Aaron Hermann of accuscore.com for bringing the central fact of the article to my attention.)

As previously discussed here, averages aren't very good for predictions because players and teams perform above and below averages. That's how you get the averages. "We" here at the blog use a system that classifies games as home wins or losses based on the stats from the game, which is 85% accurate, a large number of the misclassification being due to recovered fumbles. But it uses almost 15 individual stats to get this accurate. Is there one or two stats that we could try predicting and get close to the same accuracy?

Yes. As it turns out (unsurprisingly), the key statistic is yards per pass. Including sacks and sack yards lost, the team with the higher pass efficiency wins ~70% of games. Here's the year-by-year breakdown:

Year	% of games home team has higher pass eff.	Correlation of (Home yds/pass - Away yds/pass) with (Home pts - Away pts)	% of games won by team with higher pass eff.
1997	53.3333	0.5992	68.0952
1998	54.2857	0.6589	76.6667
1999	59.6330	0.6416	76.6055
2000	53.2110	0.6333	68.3486
2001	47.9452	0.6534	70.3196
2002	53.5714	0.6860	73.6607
2003	58.0357	0.6765	70.9821
2004	54.0179	0.6752	76.3393
2005	54.0179	0.6609	70.0893
2006	49.5536	0.6391	73.2143

So not only does the more pass efficient team win, but the correlation shows that the stronger the advantage is, the higher the margin of victory will be. The home team is more efficient passing only 53-54% of the time, showing that playing at home gives a slight edge in actual performance, but it's a smaller edge than what the actual results might indicate (~58% of games are won by the home team).

Using unadjusted stats translated into a percentage over the league average (VOLA), I tried using a logistic regression model based on home and away passing efficiency, sack rates, and interception rates on offense and defense to try and predict (Home yards per pass - Away yards per pass). Training on 1996-2005 and testing on 2006, the model was only 58% accurate in picking the team with the higher pass efficiency, while picking only 46% of home teams to be more pass efficient. On average, the absolute error was a whopping 2.11 yards. Given that each team runs 30 pass plays, we're off the mark by 63 total pass yards/game.

Predictions are only as good as your inputs. You can throw all the complicated algorithms in the world at a problem, but if the data's no good, your results won't be any good. So this is where I'm going to focus most of my creative efforts, and I hope to have a different prediction model for the 2008 season. This might require a complete redo of the data I work with, but like the Yankees and the Dolphins, if you're in "we're one piece away" mode for too long, you need to rebuild.

Read More......

Win Probabilities and Expected Wins 2007 - Week 8

The following table lists the probabilities that the home team would win each game given the rushing averages, passing averages (includes sack yards lost and sacks as pass attempts), sack rates, third down conversion rates, penalty yards, and interception and fumble rates (by number of completions and rushing plays) for both teams. A logistic regression model trained on 1996-2006 data computes the probabilities. The final score margin is Home team points - Away team points. The sum of these probabilities of victory form the expected win totals in the second table after the jump. The tables will be updated as more box scores come in. By the way, Detroit's expected win total projects out to 10 wins. "The scary thing is that Jon Kitna was right!" "I know, kids. I'm scared, too." They're 3 or 4 wins from a playoff berth with 9 games to go. I won't brag yet, but it's lookin' good.

Home Team	Away Team	P(Home Team Won) (%)	Final Score Margin
STL	CLE	38.2935	-7
CHI	DET	1.9709	-9
SF	NO	1.4568	-21
SD	HOU	99.4563	25
CAR	IND	1.7713	-24
MIA	NYG	84.6793	-3
MIN	PHI	7.4477	-7
CIN	PIT	10.8698	-11
TEN	OAK	92.0623	4
NYJ	BUF	1.4476	-10
TB	JAX	59.7037	-1
NE	WAS	99.8736	45
DEN	GB	5.5953	-6

Teams that "should have" won but didn't

Miami Dolphins (vs. Giants), Win Prob = 84.6973% Pardon my language, but **** me... Miami loses 2 of their 4 fumbles; the Giants lose only 1 of their 3 fumbles, one of which bounced directly into their O-lineman's hands. The Giants had a strong rushing game (5.1 ypc vs. 4.1), but Eli Manning managed only 2.13 yards/pass compared to Lemon's 4.45 yards/pass. So despite the lack of Ronnie Brown, they managed to outplay the Giants and still lose. This team is not an 0-16 team, not even a 1-15 team, but their terrible "luck" might make them 1-15. And by luck, I just mean that their good plays are coming more regularly but they're not coming in large enough bunches to amount to overall success.

Tampa Bay Buccaneers (vs. Jaguars), Win Prob = 59.7037% 6.47 yards/carry vs. 3.02. 5.79 yards/pass vs. 4.78. The Bucs, however, threw 3 picks. The Jags fumbled once but recovered it. That was the difference in the game.

Even without the 82-yard pass, Green Bay is pegged as having had a 76% chance of winning that game.

Team	Actual Wins	Expected Wins	Projected Win Total
AFC East
BUF	3.0	2.8684	6.5564
MIA	0.0	2.5035	5.0071
NE	8.0	7.6418	15.2835
NYJ	1.0	1.5804	3.1609
AFC North
BAL	4.0	3.5739	8.1690
CIN	2.0	2.6622	6.0851
CLE	4.0	3.4082	7.7903
PIT	5.0	5.4042	12.3525
AFC South
HOU	3.0	2.8880	5.7759
IND	7.0	6.3110	14.4251
JAX	5.0	4.3899	10.0340
TEN	5.0	4.2460	9.7051
AFC West
DEN	3.0	2.7784	6.3506
KC	4.0	4.0451	9.2460
OAK	2.0	2.2788	5.2088
SD	4.0	4.2057	9.6131
NFC East
DAL	6.0	5.5945	12.7875
NYG	6.0	4.4191	8.8382
PHI	3.0	4.4243	10.1127
WAS	4.0	3.5101	8.0232
NFC North
CHI	3.0	1.4355	2.8710
DET	5.0	4.3983	10.0532
GB	6.0	4.4170	10.0960
MIN	2.0	2.6031	5.9500
NFC South
ATL	1.0	3.0875	7.0572
CAR	4.0	2.9183	6.6703
NO	3.0	2.9711	6.7911
TB	4.0	4.9371	9.8741
NFC West
ARI	3.0	2.5830	5.9040
STL	0.0	2.1616	4.3232
SF	2.0	1.1221	2.5649
SEA	4.0	4.6317	10.5868

Read More......

Predictions 2007 Week 8

Predictions based on opponent-adjusted stats
Game	Predicted Final Score Margin	P(Home Team Wins)
NYG @ MIA	0.7053	52.9249
WAS @ NE	5.5734	68.5039
BUF @ NYJ	2.4146	59.6878
PIT @ CIN	1.5144	51.4854
OAK @ TEN	10.9037	80.3202
GB @ DEN	2.9879	59.8897
HOU @ SD	5.1858	65.5187
DET @ CHI	1.6963	51.1043
PHI @ MIN	2.2074	59.1040
IND @ CAR	-4.9354	33.7619
JAX @ TB	3.5147	62.9880
CLE @ STL	-0.2424	47.8315
NO @ SF	-0.6933	52.1203

Predictions based on unadjusted stats
Game	Predicted Final Score Margin	P(Home Team Wins)
NYG @ MIA	-1.6703	44.5811
WAS @ NE	6.6867	71.3328
BUF @ NYJ	4.5049	66.3088
PIT @ CIN	-1.9660	41.2437
OAK @ TEN	9.8863	78.0157
GB @ DEN	3.4128	60.4828
HOU @ SD	6.1622	68.7253
DET @ CHI	-0.5103	41.1834
PHI @ MIN	1.0756	54.5478
IND @ CAR	-3.6621	39.7302
JAX @ TB	3.9952	64.9115
CLE @ STL	-0.0298	48.0630
NO @ SF	0.8466	58.1237

Read More......

Win Probabilities and Expected Wins 2007 - Week 7

Night games, commentary, and expected wins table added.
The following table lists the probabilities that the home team would win each game given the rushing averages, passing averages (includes sack yards lost and sacks as pass attempts), sack rates, third down conversion rates, penalty yards, and interception and fumble rates (by number of completions and rushing plays) for both teams. A logistic regression model trained on 1996-2006 data computes the probabilities. The final score margin is Home team points - Away team points. The sum of these probabilities of victory form the expected win totals in the second table to be added after the Monday night game. The first table will be updated as more box scores come in.

Home Team	Away Team	P(Home Team Won) (%)	Final Score Margin
BUF	BAL	77.4758	5
DET	TB	64.6620	7
OAK	KC	33.6400	-2
SEA	STL	97.9805	27
MIA	NE	1.2794	-21
NO	ATL	71.4581	6
NYG	SF	97.3014	18
HOU	TEN	7.1356	-2
WAS	ARI	60.5303	2
PHI	CHI	61.6652	-3
CIN	NYJ	97.8911	7
DAL	MIN	97.7167	10
DEN	PIT	40.1822	3
JAX	IND	2.9836	-22

Teams that "should have" won but didn't
Philadelphia Eagles (vs. Bears), Win Prob = 61.6652% Astoundingly, Chicago had a better passing game than the Eagles (7.48 yards/pass vs. 5.7), but Chicago's one fumble (which they recovered) probably a large factor in this probability (without it, P(Eagles win) goes down to about 48%). Philly was much better in the running game (4.92 yards/rush vs. 3.23). But given that the game turned on that one recovered fumble, it's not surprising the game ended up being won by 3 points.

Pittsburgh Steelers (@ Broncos), Win Prob = 59.8178% Denver recovered both of their fumbles. Otherwise, Denver did indeed outperform Pittsburgh.

Team	Actual Wins	Expected Wins	Projected Win Total
AFC East
BUF	2.0	1.8829	5.0211
MIA	0.0	1.6568	3.7869
NE	7.0	6.6430	15.1841
NYJ	1.0	1.5660	3.5793
AFC North
BAL	4.0	3.5739	8.1690
CIN	2.0	2.5535	6.8094
CLE	3.0	2.7912	7.4431
PIT	4.0	4.5129	12.0345
AFC South
HOU	3.0	2.8825	6.5886
IND	6.0	5.3287	14.2098
JAX	4.0	3.9869	10.6318
TEN	4.0	3.3254	8.8676
AFC West
DEN	3.0	2.7224	7.2598
KC	4.0	4.0451	9.2460
OAK	2.0	2.1995	5.8652
SD	3.0	3.2112	8.5631
NFC East
DAL	6.0	5.5945	12.7875
NYG	5.0	4.2659	9.7506
PHI	2.0	3.4988	9.3300
WAS	4.0	3.5089	9.3570
NFC North
CHI	3.0	1.4158	3.2361
DET	4.0	3.4180	9.1146
GB	5.0	3.4729	9.2612
MIN	2.0	2.5287	6.7431
NFC South
ATL	1.0	3.0875	7.0572
CAR	4.0	2.9005	7.7348
NO	2.0	1.9857	5.2951
TB	4.0	4.3400	9.9200
NFC West
ARI	3.0	2.5830	5.9040
STL	0.0	1.7787	4.0656
SF	2.0	1.1076	2.9535
SEA	4.0	4.6317	10.5868

Read More......

Power Rankings 2007 Week 7

The power rankings for this site were developed in this article. The idea behind them is simple: if each team played one home game and one away game against every other team in the league, who would be the most successful?

The power rankings use logistic regression to predict the probability of winning. The score you see along with the rankings is the expected win total over a 16-game season based on the expected winning percentages over the 62 games (i.e. the sum of those probabilities). Adjusted and unadjusted rankings included.

Power Rankings, Logistic Regression
Rank	Team	Expected Wins
1	IND	11.4905
2	NE	11.0967
3	DAL	11.0366
4	TB	9.7785
5	PIT	9.5315
6	WAS	9.3918
7	NYG	9.1441
8	TEN	9.0731
9	JAX	8.7938
10	SD	8.7205
11	SEA	8.4443
12	PHI	8.4076
13	MIN	8.4011
14	GB	8.3821
15	DEN	8.2858
16	ARI	7.9302
17	CIN	7.8663
18	CLE	7.7844
19	HOU	7.6298
20	MIA	7.3475
21	CAR	7.2920
22	DET	7.2118
23	KC	7.0735
24	BAL	6.8962
25	ATL	6.8204
26	NO	6.5023
27	CHI	6.2434
28	BUF	6.1996
29	STL	6.0449
30	OAK	5.9200
31	NYJ	5.6766
32	SF	5.5834

Power Rankings, Opponent-adjusted
Rank	Team	Expected Wins
1	IND	11.4905
2	NE	11.0967
3	DAL	11.0366
4	TB	9.7785
5	PIT	9.5315
6	WAS	9.3918
7	NYG	9.1441
8	TEN	9.0731
9	JAX	8.7938
10	SD	8.7205
11	SEA	8.4443
12	PHI	8.4076
13	MIN	8.4011
14	GB	8.3821
15	DEN	8.2858
16	ARI	7.9302
17	CIN	7.8663
18	CLE	7.7844
19	HOU	7.6298
20	MIA	7.3475
21	CAR	7.2920
22	DET	7.2118
23	KC	7.0735
24	BAL	6.8962
25	ATL	6.8204
26	NO	6.5023
27	CHI	6.2434
28	BUF	6.1996
29	STL	6.0449
30	OAK	5.9200
31	NYJ	5.6766
32	SF	5.5834

Power Rankings, Unadjusted
Rank	Team	Expected Wins
1	NE	11.4613
2	IND	11.1798
3	DAL	11.0478
4	PIT	10.6005
5	TB	9.6857
6	WAS	9.3622
7	NYG	9.2132
8	PHI	9.0649
9	SD	9.0305
10	SEA	8.8872
11	MIN	8.6806
12	TEN	8.6470
13	JAX	8.4937
14	BAL	8.3515
15	CAR	8.2901
16	GB	8.0074
17	DEN	7.9614
18	ARI	7.8753
19	DET	7.6292
20	KC	7.6011
21	CIN	7.5983
22	CLE	7.5684
23	HOU	7.4236
24	ATL	6.7335
25	MIA	6.4393
26	OAK	6.2238
27	STL	5.7106
28	NO	5.6194
29	NYJ	5.4792
30	SF	5.4567
31	CHI	5.4103
32	BUF	5.2663

Read More......

The Value of Homefield Advantage 2007 Week 7

One of the things I've learned in my football research is that the value of home-field advantage varies pretty widely from year to year, especially with interconference games. Because prediction systems tend to have a big bias towards the home team, this can have a large impact on accuracy. So throughout the season, I'll be keeping track of home team winning percentage and average final score margin (home team points - away team points) for interconference, interdivision, and intradivision matchups. If you're interested in that sort of thing, it can help you with betting on the spread (hint).

The pattern this season so far shows that you should bet on interconference home teams, especially if they're the underdogs, and stay away from intradivision games. There could be regression to the mean, but I don't believe it would be severe enough that betting on home teams in intradivision games would become good.

All Games
Home Team Win %: 59.2233%
Avg. Final Score Margin: 2.1553

Interconference
Home Team Win %: 69.2308%
Avg. Final Score Margin: 3.9231

Interdivision, Intraconference
Home Team Win %: 67.5676%
Avg. Final Score Margin: 4.5135

Intradivsion
Home Team Win %: 45.0000%
Avg. Final Score Margin: -1.1750

Read More......

Projected Final Standings 2007 Week 7

Using the projected win probabilities from the logistic regression power rankings, I estimated which games each team would win on the rest of their respective schedules. And then I summed the projected wins with the actual wins so far to get their projected win totals. The teams are sorted by division. For the record, New England's only projected loss is on the road to Indianapolis. If you look at the stats page for week 6, you'll see the major reason likely has to do with the perceived disparity in rush offense.


Using opponent-adjusted stats

Projected Final Standings
Team	Projected Win Total
AFC East
BUF	4
MIA	5
NE	15
NYJ	3
AFC North
BAL	6
CIN	8
CLE	9
PIT	12
AFC South
HOU	6
IND	16
JAX	10
TEN	11
AFC West
DEN	9
KC	8
OAK	3
SD	8
NFC East
DAL	15
NYG	10
PHI	7
WAS	8
NFC North
CHI	5
DET	6
GB	12
MIN	9
NFC South
ATL	3
CAR	7
NO	4
TB	13
NFC West
ARI	8
STL	1
SF	4
SEA	11

Read More......