Djordje Posted November 14, 2009 Share Posted November 14, 2009 “Goal Rating System is statistical football betting system based on simple fact that teams who scored more goals and conceded fewer in last several games have better chances of winning their next game. Match rating is calculated on last 6 league games as following: * Home team rating = Home team goals scored - Home team goals conceded * Away team rating = Away team goals scored - Away team goals conceded * Match rating = Home team rating - Away team rating With enough amount of historical data, Match rating calculated like this is used for determining fair odds (or fair probabilities) for home win, draw and away win. If the Match rating between two sides is equal to 0, it means we have match between two equal sides, and probability for a home win by this model is 46.5%.” I've been using this system for a while (around 8.50% yield on more than 200 bets during year 2009), but this thread will be different take with different rules: * English leagues only * Fixed odds - Back or Lay * Stakes on 1-10 scale using Kelly criteria * Match ratings in range (-1, +1) This filtering will throw some strange bets probably, but the aim is to see what happens in games between equally matched sides according to this system. This is paper trial only. Quote Link to comment Share on other sites More sharing options...
Djordje Posted November 14, 2009 Author Share Posted November 14, 2009 Re: Goal Rating System Numbers in brackets are Match ratings described above 11/14/2009 English League One Yeovil (-1) Southend 44.91% 30.14% 24.95% Back Yeovil @2.50 skybet, stake 8/10 English League Two Rochdale (1) Chesterfield 48.03% 29.56% 22.41% Back Draw @3.50 skybet, stake 1/10 Shrewsbury (0) Torquay 46.47% 29.88% 23.65% Lay Shrewsbury @2.00 betfair, stake 7/10 Blue Square Premier Wrexham (1) Hayes 48.03% 29.56% 22.41% Lay Wrexham @1.75 betfair, stake 10/10 Quote Link to comment Share on other sites More sharing options...
Bedlam Posted November 14, 2009 Share Posted November 14, 2009 Re: Goal Rating System :hopeGood luck Gjordje, I dabbled (too briefly) with a similar system, will be watching with interest. Quote Link to comment Share on other sites More sharing options...
froment Posted November 14, 2009 Share Posted November 14, 2009 Re: Goal Rating System Wow, that's quite a successfull beginning - 3 out of 4, one lost at the lowest stakes, which adds up to a nice profit of about 40 units, from 26 staked! :clap Good luck with this strategy! :ok Quote Link to comment Share on other sites More sharing options...
Djordje Posted November 14, 2009 Author Share Posted November 14, 2009 Re: Goal Rating System lol, beginner's luck :loon:unsure Quote Link to comment Share on other sites More sharing options...
Djordje Posted November 15, 2009 Author Share Posted November 15, 2009 Re: Goal Rating System 11/14/2009 English League One Yeovil (-1) Southend 44.91% 30.14% 24.95% Back Yeovil @2.50 skybet, stake 8/10 Result 1:0, profit +12.00 English League Two Rochdale (1) Chesterfield 48.03% 29.56% 22.41% Back Draw @3.50 skybet, stake 1/10 Result 2:3, profit -1.00 Shrewsbury (0) Torquay 46.47% 29.88% 23.65% Lay Shrewsbury @2.00 betfair, stake 7/10 Result 1:1, profit +10.00 Blue Square Premier Wrexham (1) Hayes 48.03% 29.56% 22.41% Lay Wrexham @1.75 betfair, stake 10/10 Result 0:2, profit +10.00 Record Bets: 4 Staked: 29 Profit: 31 Yield 106% Quote Link to comment Share on other sites More sharing options...
bogdancavnic Posted November 17, 2009 Share Posted November 17, 2009 Re: Goal Rating System hi Djordje, one question:how calculate the probability for one result in percent? thank you Good luck with your system Quote Link to comment Share on other sites More sharing options...
Djordje Posted November 18, 2009 Author Share Posted November 18, 2009 Re: Goal Rating System hi Djordje, one question:how calculate the probability for one result in percent? thank you Good luck with your system Probabilities are calculated from huge amount of historical data - that's statistical and mathematical part of this story I'm not educated enough to write about. Basically, there is formula which calculates probabilities for all three outcomes and the only parameter it uses is Match rating which is explained in first post. I'll paste probabilities for all the games this weekend. Quote Link to comment Share on other sites More sharing options...
Djordje Posted November 19, 2009 Author Share Posted November 19, 2009 Quote Link to comment Share on other sites More sharing options...
Djordje Posted November 19, 2009 Author Share Posted November 19, 2009 Re: Goal Rating System These are upcoming fixtures for this weekend. Tables show Match ratings, percentages and fair odds. :ok Quote Link to comment Share on other sites More sharing options...
Lardonio Posted November 19, 2009 Share Posted November 19, 2009 Re: Goal Rating System Hmm, Djordje, your model sounds interesting, but when I see odds like 9.6 on Wolves (or 1.4 on Chelsea), 2.06 on ManUtd at home and 2.3 on Arsenal away to Sunderland I get a bit suspicious that your model does not produce realistic forecasts, because in my opinion (and the bookmaker's). From what I understand your model calculates a match rating based on goals scored, then looks up results based on that match rating. So for example Arsenal facing Wolves with a match rating of 5 gives the same percentages as Arsenal facing Manchester United with a match rating of 5. Am I correct? Quote Link to comment Share on other sites More sharing options...
Grex Posted November 19, 2009 Share Posted November 19, 2009 Re: Goal Rating System Sorry, Lardonio, I can't agree with you. The bookies will always reduce the odds on the "big" teams to well below 100% value, simply because they know most of the money will be backing those teams. The various systems I have developed to give 1-X-2 probabilities invariably show that the value of odds offered on the likes of Man United, Chelsea and Arsenal are around the 75% value mark. I don't understand your comment comparing an Arsenal-Wolves match with an Arsenal-Man United match. If the ratings for the two matches were the same then, yes, the probabilities would be the same..... but I'm sure the ratings for these particular matches would unlikely to be the same ;) Quote Link to comment Share on other sites More sharing options...
Djordje Posted November 19, 2009 Author Share Posted November 19, 2009 Re: Goal Rating System Hmm, Djordje, your model sounds interesting, but when I see odds like 9.6 on Wolves (or 1.4 on Chelsea), 2.06 on ManUtd at home and 2.3 on Arsenal away to Sunderland I get a bit suspicious that your model does not produce realistic forecasts, because in my opinion (and the bookmaker's). From what I understand your model calculates a match rating based on goals scored, then looks up results based on that match rating. So for example Arsenal facing Wolves with a match rating of 5 gives the same percentages as Arsenal facing Manchester United with a match rating of 5. Am I correct? Yes, match rating of 5 is always the same, nevermind if United plays Wolves or Arsenal. I know this sounds strange, but that's the way it is with this model, and it is based on huge number of games. "Big teams" are always different story. Manchester United, Arsenal, Chelsea and Liverpool will be always be red hot favorites unless they face each other, and you'll never get fair prices on them. And do you really think that 1.16 is fair price for Chelsea to beat Wolverhampton? Quote Link to comment Share on other sites More sharing options...
Lardonio Posted November 20, 2009 Share Posted November 20, 2009 Re: Goal Rating System Sorry' date= Lardonio, I can't agree with you. The bookies will always reduce the odds on the "big" teams to well below 100% value, simply because they know most of the money will be backing those teams. The various systems I have developed to give 1-X-2 probabilities invariably show that the value of odds offered on the likes of Man United, Chelsea and Arsenal are around the 75% value mark. I don't understand your comment comparing an Arsenal-Wolves match with an Arsenal-Man United match. If the ratings for the two matches were the same then, yes, the probabilities would be the same..... but I'm sure the ratings for these particular matches would unlikely to be the same ;) Firstly, all research shows that the favourites are actually the smartest teams to bet on as it's better value. Unfortunately I didn't manage to find the sources of this research in Google now, but I'm sure it could be dug up. EDIT: I did find a lot of articles now, although most of them are not easily available, the 'favourites are not value' myth is a well known myth known as the 'long odds bias' - http://favourite-longshot-bias.behaviouralfinance.net/ I am sure this has been discussed on PL before. Secondly, the ratings for the two matches would be the same with Djordje's system provided they had the same goal differences, which could easily happen. Djordje has confirmed this in the post above. Quote Link to comment Share on other sites More sharing options...
Djordje Posted November 20, 2009 Author Share Posted November 20, 2009 Re: Goal Rating System One match tonight. DateHostRatingGuestH[%]D[%]A[%]HDABetOddsStake11/20/2009Southend1Milton Keynes48.03%29.56%22.41%2.0843.3844.464 Back Southend 3.00 bet365 10 Quote Link to comment Share on other sites More sharing options...
Djordje Posted November 20, 2009 Author Share Posted November 20, 2009 Quote Link to comment Share on other sites More sharing options...
Grex Posted November 20, 2009 Share Posted November 20, 2009 Re: Goal Rating System Great start, Djordje..... :clap thanks to an injury time penalty :tongue2. I chickened out of backing Southend, and layed MK Dons.... still, a nice profit.... thanks. By the way, your "name" suggests your roots are from ex-Yugoslavia.... correct? I lived for 8 years in Montenegro and am very fond of the Balkans. Quote Link to comment Share on other sites More sharing options...
Djordje Posted November 21, 2009 Author Share Posted November 21, 2009 Quote Link to comment Share on other sites More sharing options...
Djordje Posted November 21, 2009 Author Share Posted November 21, 2009 Re: Goal Rating System Great start' date= Djordje..... :clap thanks to an injury time penalty :tongue2. I chickened out of backing Southend, and layed MK Dons.... still, a nice profit.... thanks. By the way, your "name" suggests your roots are from ex-Yugoslavia.... correct? I lived for 8 years in Montenegro and am very fond of the Balkans. thanks Grex :ok and yes, I'm from Serbia ;) Quote Link to comment Share on other sites More sharing options...
Grex Posted November 21, 2009 Share Posted November 21, 2009 Re: Goal Rating System Good day's results.... well done :clap. One point..... shouldn't the amount "staked" for lay bets be based on liability ? Quote Link to comment Share on other sites More sharing options...
Djordje Posted November 21, 2009 Author Share Posted November 21, 2009 Re: Goal Rating System Good day's results.... well done :clap. One point..... shouldn't the amount "staked" for lay bets be based on liability ? :unsure Quote Link to comment Share on other sites More sharing options...
Djordje Posted November 22, 2009 Author Share Posted November 22, 2009 Quote Link to comment Share on other sites More sharing options...
Djordje Posted November 22, 2009 Author Share Posted November 22, 2009 Re: Goal Rating System Bets counter13Strike rate0.54Staked96.00Profit29.80Yield31.04 Quote Link to comment Share on other sites More sharing options...
Grex Posted November 22, 2009 Share Posted November 22, 2009 Quote Link to comment Share on other sites More sharing options...
Djordje Posted November 22, 2009 Author Share Posted November 22, 2009 Re: Goal Rating System Excellent results' date= Djordje.... well done :clap. What I meant in my earlier post was that the effective stake on lay bets is the liability. Your results so far would then be....... (sorry about the formatting)..... your yield would be 29.80/88.92 = 33.6%.... even better than your calculation..... perhaps I've got something wrong, but this is how I always calculate yield from lay bets. thanks for your interest and input, Grex :ok Why do you think yield should be calculated different for lay bets? Stake and profit are always the same thing, nevermind if it's won as back or lay, so I thought there shouldnt be any difference :unsure Quote Link to comment Share on other sites More sharing options...
Grex Posted November 23, 2009 Share Posted November 23, 2009 Re: Goal Rating System I think that for lay bets the yield should be profit divided by "risk". If somebody was running a system of laying outsiders, then for a lay bet at odds of 21.00, with a stake of 10 units (i.e. backers stake), their liability (risk) would be 200 units. If they were to follow your approach, they would claim 100% yield (less commission) for a winning bet, but a more reasonable assessment of yield would be the profit (10 units, less commission) divided by 200 units, i.e 5% (less commission). Quote Link to comment Share on other sites More sharing options...
Djordje Posted November 24, 2009 Author Share Posted November 24, 2009 Re: Goal Rating System I think that for lay bets the yield should be profit divided by "risk". If somebody was running a system of laying outsiders' date= then for a lay bet at odds of 21.00, with a stake of 10 units (i.e. backers stake), their liability (risk) would be 200 units. If they were to follow your approach, they would claim 100% yield (less commission) for a winning bet, but a more reasonable assessment of yield would be the profit (10 units, less commission) divided by 200 units, i.e 5% (less commission). now I got the point :ok Quote Link to comment Share on other sites More sharing options...
Djordje Posted November 24, 2009 Author Share Posted November 24, 2009 Quote Link to comment Share on other sites More sharing options...
Djordje Posted November 24, 2009 Author Share Posted November 24, 2009 Re: Goal Rating System Grex's advice regarding stakes accepted - just didnt have time to change the tables right now :ok Quote Link to comment Share on other sites More sharing options...
Djordje Posted November 24, 2009 Author Share Posted November 24, 2009 Quote Link to comment Share on other sites More sharing options...
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