Rating system from Football-data (...math ) help needed !!

[Guest mcjoint]

I'm working on a spreadsheet, with a lot of different rating systems. Came across the "Rating systems for fixed odds football match prediction" on www.football-data.co.uk/ratings.pdf. There are a few things I can't quite figure out : ( I'm not much of a math buff..so be patient ) 1. In the document there's the following equation : y = 1.56X + 46,47 y=prob. of a homewin X=match rating. The 46,47 is the homewin % when the matchrate is 0 But where does the 1,56 come from ? And why is the awayequation : y=0.03X2 - 1.27X + 23.65 drawequation : y=0.03X2 - 0.29X + 29.48 2. As I've understood it, the distribution of H/D/A for a matchrate of 0, is virtually the same as the dist. of all games played ( regardless the matchrates ). Could you take the easy way out, and just use the dist. for all games and run that through the equation ? Of course it wouldn't give you the accuracy of the real statistically calculated values, but it would somewhere around there....wouldn't it ?!? Hope somebody can help me.

[Guest muppet]

Re: Rating system from Football-data (...math ) help needed y = 1.56X + 46,47 the above equation basically describes the best fit line for that data. so if you tap in y, you can find x. 1.56X means multiply 1.56 by the value X. the 1.56 is the gradient (steepness) of the line the +46.47 part is the intercept (where it crosses the y axis) so in your example (1.56 x 0) + 46.47 = 46.47