Betting Market Power Rankings – Week 15

by Michael Beuoy

Here are the week 15 betting market power rankings. As noted last week (link), I have modified the methodology to now incorporate the point spreads for the upcoming week, if they’re available (week 16, in this case).

Methodology
The goal I had was to generate a set of point-based rankings that would best predict how the betting market would set the point spread for the coming week’s matchups. The better I was able to match the point spread, the better the rankings were a reflection of the market’s estimate of team by team strength. Through trial and error experimentation, I found that using point spreads for the most recent five weeks (with higher weighting given to more recent weeks), combined with an adjustment that accounted for actual game outcomes, generated the best predictive accuracy. More detail here

The Rankings
Here are the Betting Market Power Rankings for Week 15:

Glossary:
LSTWK - The betting market rank as of the prior week (using the same methodology).
GPF - Stands for Generic Points Favored. It’s what you would expect a team to be favored by against a league average opponent at a neutral site.
GWP - Stands for Generic Win Probability. I converted the GPF into a generic win probability using the following formula: GWP = 1/(1+exp(-GPF/7)). This gives a more direct comparison to the ANS rankings.
ANS RNK - The Advanced NFL Stats Team Efficiency rankings for the same week.
ANS GWP - The Advanced NFL Stats Generic Win Probability for the same week.

RANK	Team	LSTWK	GPF	GWP	ANS RNK	ANS GWP
1	GB	1.0	10.0	0.81	3	0.73
2	NE	2.0	8.0	0.76	4	0.67
3	NO	3.0	7.5	0.74	5	0.65
4	BAL	5.0	5.5	0.69	7	0.64
5	PIT	4.0	5.5	0.69	2	0.76
6	SF	6.0	4.5	0.65	17	0.50
7	ATL	7.0	3.5	0.62	11	0.55
8	NYJ	9.0	3.0	0.61	12	0.54
9	DAL	8.0	3.0	0.60	8	0.62
10	DET	12.0	2.0	0.58	10	0.61
11	SD	14.0	2.0	0.58	14	0.52
12	PHI	16.0	2.0	0.57	9	0.61
13	NYG	10.0	1.5	0.56	6	0.64
14	TEX	13.0	1.5	0.55	1	0.77
15	DEN	20.0	0.0	0.50	24	0.39
16	TEN	17.0	-0.5	0.49	18	0.48
17	CIN	15.0	-0.5	0.48	13	0.52
18	MIA	11.0	-0.5	0.48	20	0.45
19	CHI	21.0	-0.5	0.47	15	0.51
20	SEA	23.0	-1.0	0.46	25	0.38
21	RAI	18.0	-1.5	0.44	16	0.50
22	ARZ	22.0	-2.0	0.43	22	0.43
23	CAR	19.0	-2.5	0.41	23	0.40
24	WAS	26.0	-2.5	0.41	21	0.44
25	MIN	25.0	-3.0	0.40	28	0.33
26	BUF	24.0	-3.5	0.37	19	0.48
27	CLE	29.0	-5.5	0.31	27	0.34
28	JAC	30.0	-6.0	0.30	26	0.36
29	TB	28.0	-6.0	0.30	30	0.30
30	KC	27.0	-6.5	0.29	31	0.28
31	STL	31.0	-8.5	0.23	29	0.32
32	IND	32.0	-9.0	0.21	32	0.26

• Obligatory Tebow-Watch – Denver moved up 5 spots to number 15, and a GWP of 0.50.
• The ANS model still disagrees pretty significantly with the Betting Market on San Francisco.
• I’m surprised the Giants are ranked as low as they are.


Prediction of This Week’s Point Spreads

See below for how well the ranking methodology predicted this week’s point spreads:

Game	Pred Line	ActLine	Diff
BAL @ SD	-0.5	-2.0	-1.5
CAR @ TEX	6.0	6.5	0.5
CIN @ STL	-5.5	-6.0	-0.5
CLE @ ARZ	5.0	6.5	1.5
DAL @ TB	-5.5	-6.5	-1.0
DET @ RAI	-1.5	-1.0	0.5
GB @ KC	-13.5	-14.0	-0.5
JAC @ ATL	12.0	11.5	-0.5
MIA @ BUF	-1.5	1.0	2.5
NE @ DEN	-5.0	-6.0	-1.0
NO @ MIN	-8.5	-7.0	1.5
NYJ @ PHI	0.5	3.0	2.5
PIT @ SF	0.0	2.5	2.5
SEA @ CHI	2.5	4.0	1.5
TEN @ IND	-6.0	-6.5	-0.5
WAS @ NYG	7.0	7.0	0.0