NBA - Home Win Probability Using SRS

The following equations can be used to determine true money-line and true point spreads for the NBA. The basis of them are using Adjusted Simple Rating System (aSRS), which can be calculated by:

 

      Where:

• aSRS = adjusted simple rating system
• G = games played
• SRS = simple rating system

Simple Rating System—from what I've seen—is only published on Basketball-Reference, and is calculated by adding the team's margin of victory and strength of schedule. Justin Kubatko of Statitudes compiled the results of the 1976–1977 through 2012–2013 NBA seasons using aSRS, and created the following logit equation to predict the probability of the home team winning:

      Where:

• e = Euler's number, the base of natural logarithm
• dSRS = Home team's aSRS – Away team's aSRS

This answer will produce a decimal (i.e. 0.5277) which can be multiplied by 100 to get the implied probability (i.e. 52.77%). This implied probability can be converted into a true money-line by using a convertor. Finally, this probability can be converted into a point spread using the following equation:

Sources:
Kubatko, Justin (November 13, 2013). "Home Win Probability Using SRS." Statitudes. Retrieved November 26, 2013.

Pythagorean Theorem for Season Wins

x = 1.83 - MLB, 2.37 - NFL, 16.50 - NBA, 10.00 - CBB, 2.00 - NHL, 1.70 - MLS

NCAAF, NFL, NBA - Spread to Fair Money Line

Spread	NCAAF	NFL	NBA
0	100	100	100
1.5	120	122	113
2	127	130	119
2.5	135	139	129
3	143	149	141
3.5	152	159	153
4	161	170	167
4.5	171	181	182
5	182	194	198
5.5	193	207	216
6	205	221	236
6.5	217	236	258
7	231	252	283
7.5	245	269	310
8	260	288	342
8.5	276	307	377
9	293	328	419
9.5	311	351	466
10	330	375	523
10.5	350	400	579
11	372	427	645
11.5	395	457	720
12	419	488	807
12.5	445	521	910
13	472	557	1033
13.5	501	595	1179
14	532	635	1358
14.5	565	678	1579
15	599	725	1857
15.5	636	774	2216
16	675	827	2693
16.5	717	883	3351
17	761	944	4305
17.5	808	1,008	N/A
18	858	1,077	N/A
18.5	910	1,150	N/A
19	966	1,229	N/A
19.5	1,026	1,313	N/A
20	1,089	1,402	N/A
20.5	1,156	1,498	N/A
21	1,227	1,600	N/A
21.5	1,303	1,709	N/A
22	1,383	1,826	N/A
22.5	1,468	1,950	N/A
23	1,558	2,083	N/A
23.5	1,654	2,226	N/A
24	1,756	2,377	N/A
24.5	1,864	N/A	N/A
25	1,978	N/A	N/A
25.5	2,100	N/A	N/A
26	2,229	N/A	N/A
26.5	2,366	N/A	N/A
27	2,512	N/A	N/A
27.5	2,666	N/A	N/A
28	2,830	N/A	N/A
28.5	3,004	N/A	N/A
29	3,189	N/A	N/A
29.5	3,385	N/A	N/A
30	3,594	N/A	N/A
30.5	3,815	N/A	N/A
31	4,049	N/A	N/A

Sources:
[1] "College Football Money Lines." WizardOfOdds.com. Retrieved October 13, 2013.
[2] "Betting on the NBA." WizardOfOdds.com. Retrieved October 16, 2013
[3] "Betting on the NFL." WizardOfOdds.com. Retrieved October 16, 2013

NBA - Middling Totals

Difference	Middle %
0.0	0.95%
0.5	3.35%
1.0	6.08%
1.5	7.83%
2.0	10.00%
2.5	11.94%
3.0	14.07%
3.5	16.81%
4.0	19.58%

Source: Detroit, Johnny (January 18, 2012). "Middling Totals." Pregame.com. Retrieved October 11, 2013.