tag:blogger.com,1999:blog-38600807.post6070531493803094254..comments2018-06-02T14:19:34.554-04:00Comments on Advanced Football Analytics (formerly Advanced NFL Stats): Game Probabilities - Week 15Unknownnoreply@blogger.comBlogger9125tag:blogger.com,1999:blog-38600807.post-87896139439800205892013-12-19T08:54:48.510-05:002013-12-19T08:54:48.510-05:00The equation is: (H*(1-A)*F) / (H*(1-A)*F+(1-H)*A*...The equation is: (H*(1-A)*F) / (H*(1-A)*F+(1-H)*A*(1-F))<br /><br />Where H is the GWP of the home team, A the GWP of the away team, and F the home field advantage constant of 0.575. I've used this to get the game win probabilities a day early for the whole year and they are always within rounding error.Jameshttps://www.blogger.com/profile/01838293735141324662noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-23867023308653746422013-12-15T23:34:51.257-05:002013-12-15T23:34:51.257-05:00Andrew-HFA has not changed. It does not directly c...Andrew-HFA has not changed. It does not directly correspond to a probability. When teams are close in strength, HFA is larger than when the game is lopsided. It averages 57.5%.Brian Burkehttps://www.blogger.com/profile/12371470711365236987noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-45509261365443790002013-12-15T16:28:38.905-05:002013-12-15T16:28:38.905-05:00So @Andrew Foland, that would mean you add about 0...So @Andrew Foland, that would mean you add about 0.3022 to the logit for the home team and subtract it from the away team?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-73095984131922182792013-12-14T20:56:38.817-05:002013-12-14T20:56:38.817-05:00I've backed out that the HFA adjustment for th...I've backed out that the HFA adjustment for the NYT game probabilities is ~57.5% winning at home. This has actually changed from last season, when it was closer to 62%--I asked a couple weeks ago when that had been changed, but I think it was after everyone had moved to the next thread.Andrew Folandhttp://nuclearmangos.blogspot.comnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-29529643067343325382013-12-14T13:25:21.143-05:002013-12-14T13:25:21.143-05:00What is the Packers probablilty of winning when yo...What is the Packers probablilty of winning when you account for Rodgers being out?Ben Crannyhttps://www.blogger.com/profile/06663325027175414913noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-84895894681788134972013-12-13T21:59:21.728-05:002013-12-13T21:59:21.728-05:00Thank you, Mike B.
I'm unsure of how to factor...Thank you, Mike B.<br />I'm unsure of how to factor in home field advantage. The ahome coefficient at http://www.advancednflstats.com/2011/09/weekly-game-probabilities.html is not equal to the twice the constant term as http://www.advancednflstats.com/2009/01/how-model-works-detailed-example.html suggests it should be. The results I get by just ignoring the constant term and adding +/- 0.5*0.748577 to the logits for the home/away team gives results that don't match the NYT values but aren't far off; however, in this case I don't know what the constant term $C['const'] = -0.4619 is even for.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-74826024229032865062013-12-13T16:30:08.488-05:002013-12-13T16:30:08.488-05:00Houston's GWP is 0.41, not 0.45. And you don&#...Houston's GWP is 0.41, not 0.45. And you don't have to do the strength of schedule adjustment. It is already factored into the GWP.Mike Bnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-76613615709195875322013-12-13T11:00:07.647-05:002013-12-13T11:00:07.647-05:00Do you use a standard 3-point (or certain percenta...Do you use a standard 3-point (or certain percentage) adjustment for homefield advantage, or is it calculated in some other way?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-83872664815090492822013-12-13T09:57:45.634-05:002013-12-13T09:57:45.634-05:00Trying to reproduce these probabilities and would ...Trying to reproduce these probabilities and would love some pointers.<br /><br />The GWPs as given are 0.45 for Houston and 0.47 for Indy. Indy's had an average schedule (Opp GWP = 0.5) but Houston has had a weak one (Opp GWP = 0.45) and so I find that Houston's opponent-adjusted GWP is 0.45.<br /><br />For the corresponding opponent-adjusted logits I get -0.565 for Houston and -0.120 for Indy. Adding on a penalty of -0.4619 for being away and computing to a win probability for Houston yields 29%, well under the 37% on the NY Times.<br /><br />I'm using the Week 14 stats at http://www.advancednflstats.com/2013/12/team-efficiency-rankings-week-14.html and the -0.4619 figure is from http://www.advancednflstats.com/2011/09/weekly-game-probabilities.html<br />Anonymousnoreply@blogger.com