new idea on prices. why do we bother?

[muppet77]

i have been thinking about generating prices for the purposes of football betting. many of us try to look at elo type rating systems to convert to actual % chances of H, D, A, and then imply odds from these. i was wondering - what if you just CAN'T find the true chance of events ocurring? we all search for the Holy Grail, but suppose it is just not possible? i think (or suggest) this because i was thinking about bookies odds, and asked myself a few roundabout questions: do they really know the exact price of a match? well, not exactly. do they have a fair idea of the price of the match? well, generally. do they offer that price? no, i believe they have a good idea, then they apply their over round and create a price for the punters. as long as this buffer zone or margin of safety is large enough, then they will win in the long term. so is it worthwhile trying to determine if a team has a 56% of a win or tweaking the sytem / rating to see if we can make it more accurate and the chance is actually 58%? what's the difference? what i think is worth looking at is something along the lines of "games like"......that is, rather than saying, "right, ManU are playing Liverpool, and my rating sytem gives 12.4 points to ManU at home and 9.6 to Liverpool which converts to HDA of 57%, 25%, 18%".... instead saying "ok, ManU are a top team who are playing at home against a second level team" or categorising 5 or 6 TYPES of games that can be played. obviously this needs discussion, but it could be something like type 1: an even steven match - very tight type 2: a potential league winner against a demotion favourite type 3: a team that is better than another but may draw etc obviously this part is the crucial part and can be done a number of ways. what factors to look at? home/away goal diff? league positon? point per game? once the measure has been chosen then we can almost work backwards. group each TYPE of match and then work out the average odds offered by a bookie. hopefully they will be similar for each type of game. for example a 'top vs bottom' type has average odds of 1.30 and a 'class one against a class two' type game may average odds of 1.75. thus by doing this, tissue prices are almost being found. (as a tester i found the average odds for games that finish as a draw, +1, +2, -1, -2 there is a really strong pattern in the average odds, not that this is immediately useful, but suggests that there is a pattern) once these averages have been found (they will be inaccurate for INDIVIDUAL games) they can be applied to betting situations. so if a game is identified as "type 1" and the tissue price suggests home should be 1.30 and betfair is offering 1.65, then you can back that team. i just believe that many of us are trying to overcomplicate the process.....we may calculate Bolton to have a 35.765% chance of winning. well, on the day they have injuries, players' motivation, weather etc which all will affect the odds. the bookies can't get all of this spot on, and so they use the over round as protection. wow, that's the longest post i've made. does anyone: ...understand what i'm trying to say? ...have any advice or contribution? ...think i'm talking bobbins? :wall

[duffman]

Re: new idea on prices. why do we bother? muppet77 interestingly enough, i've had a similar idea as yourself for years and was actually looking to share in others opinions but havent had much luck. I've tried a few postings but I dont think people have a clue what i'm on about. I also believe that the solution to finding value is to compare current odds in a market with the same odds in a previous market under similar circumstances. The only problem comes with defining those circumstances..and i think when you talk about 'types' that you have the same basic idea as myself. I think, for the FA Cup final a bookie would say something like..ok, both are top class teams who are well rested and no particular run of form. Man U will be in high confidence after winning the league, but I dont think that will matter..so I think we will call it even and go 2.7 on both teams... don't see an elo ratings or percentages there... So what if an online system (obviously this is a very basic example) could give you the previous odds under the same circustances i.e. when a team: team type - title contenders rest period - well rested form - neutral confidence - high played against a team: team type - title contenders rest period - well rested form - neutral confidence - normal You could instantly compare odds and find: ManU Draw Chelsea -2.7--- 3--- 2.7---- Current Odds -2.2-- 2.9 ---3----- Average of Previous Odds (under similar circumstances) Which finds that the 2.7 on ManU may be value. You can then check other markets as well under those circumstances. Let me know what you think. Not sure if youre a programmer, but i've an idea on how to make this interesting and make such a system work..