saadat68 Posted May 9, 2012 Share Posted May 9, 2012 Hello i want to use elo ratting system but i dont understand completely i have some questions 1- here we have : Team1 had a 64% chance of winning, Team2 36% but football is win - draw and lose what is chance of draw ? 2- if i want find fair odds can i use these chance and convert them to odd ? thanks and sorry for bad english :eyes Elo*************************************** ' The ratings are based on the following formula: ' ' Rn = Ro + KG × (W - We) ' ' or ' ' P = KG(W - We) ' ' Where; ' Rn = the new rating ' Ro = the old (pre-match) rating ' K = the Weight Constant for the tournament played ' * 60 for World Cup finals; ' * 50 for continental championship finals and major intercontinental tournaments; ' * 40 for World Cup and continental qualifiers and major tournaments; ' * 30 for all other tournaments; ' * 20 for friendly matches. ' G = the Goal difference adjustment for the Weight Constant ' It is increased by half if a game is won by two goals, ' by 3/4 if a game is won by three goals, ' and by 3/4 + (N-3)/8 if the game is won by four or more goals, ' where N is the goal difference. ' W = the result of the game (1 for H, 0.5 for D, and 0 for A) ' We = the Win Expectancy - the expected result ' We = 1 / (10(-dr/400) + 1) ' dr equals the difference in ratings plus 100 points for a team playing at home. ' P = Points Change '************************************************* ************************************************** Lets look at an example of adjusting ratings: Two results, score in brackets: (4) Team1 vs Team2 (2) (1) Team3 vs Team1 (5) The 3 teams start with 1000 points each and this could be at the start of each season or from the earliest record you have. Now, in order for the ratings to work, we need to update both teams ratingafter every game. To get our numbers for the equations, refering to the info above, lets get the easiest one first!: Difference in ratings including home team weighted with 100 points (dr): dr = ((RatingHomeTeam + 100) - RatingAwayTeam) dr = ((1000 + 100) - (1000) dr = 100 Win Expectancy (We): We = 1/(10^(-dr/400) + 1) We = 1/(10^(-100/400) + 1) We = 1/(10^-0.25 + 1) We = 1/(0.56 + 1) We = 1/1.56 We = 0.64 so Team1 had a 64% chance of winning, Team2 36% WeightConstant for league games (K) K = 30 Goal Difference is 2 (G) G = 1.5 Result of the game was H (W): W = 1 Win Expectancy (We): We = 0.64 Points change (P): P = KG(W - We) P = (30 * 1.5) * (1 - 0.64) P = 45 * 0.36 P = 16.20 Team1 gets the points: 1000 + (16.20) = 1016.20 Team2 loses the points: 1000 - (16.20) = 983.80 Quote Link to comment Share on other sites More sharing options...
saadat68 Posted May 9, 2012 Author Share Posted May 9, 2012 Re: elo system - please explain anybody cant help me ? Quote Link to comment Share on other sites More sharing options...
saadat68 Posted May 9, 2012 Author Share Posted May 9, 2012 Re: elo system - please explain I search and understand some questions but i have still 2 questions I dont know how to calculate probability chance of draw and how to convert to odds of win - draw and lost Quote Link to comment Share on other sites More sharing options...
pinkisntwell Posted May 15, 2012 Share Posted May 15, 2012 Re: elo system - please explain I search and understand some questions but i have still 2 questions I dont know how to calculate probability chance of draw and how to convert to odds of win - draw and lost There isn't a certain way you do this, you have to model that as well. Draws have difference probabilities depending on the league and the competing teams. Quote Link to comment Share on other sites More sharing options...
saadat68 Posted May 19, 2012 Author Share Posted May 19, 2012 Re: elo system - please explain hello thanks for your answer but i know bettors can convert elo chance to bookie odds how they can convert ? Quote Link to comment Share on other sites More sharing options...
analyzer Posted June 19, 2012 Share Posted June 19, 2012 Re: elo system - please explain What you need is - convert your We into home/draw/away probabilities (Ph/Pd/Pa). Below is a method how to do this. Calculte We for e.g. 1000 past games. Then devide all games into, say, 10 groups: 1) 0.0 Quote Link to comment Share on other sites More sharing options...
A Woods Posted June 30, 2012 Share Posted June 30, 2012 Re: elo system - please explain The ELO system is very well explained in the book 'The Rating of Chess Players' by Arpad Elo himself. Its available on Amazon. I bought it when it first came out and was impressed. I havent read it since then. Quote Link to comment Share on other sites More sharing options...
methuselah Posted June 30, 2012 Share Posted June 30, 2012 Re: elo system - please explain If you go to Prematches you can see an Elo system in action. Seems reasonably accurate but the highest rating percentages are at poor odds. Not too sure it would be profitable. Quote Link to comment Share on other sites More sharing options...
Cassius Marcellus Posted July 1, 2012 Share Posted July 1, 2012 Re: elo system - please explain The simplest way to see if your draw price is correct, with no systems, graphs, degrees in maths or studying football results all night, is to go onto Betfair and lay the first price for a new market. If it gets taken immediately, you were too big. :rollin Quote Link to comment Share on other sites More sharing options...
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