[Fooball bet optimizer for Betfair]

Re: Fooball bet optimizer for Betfair Holy moly, I haven't realized how long the post came out to be... I'll have to learn some mastery of briefness :)

[Fooball bet optimizer for Betfair]

Hi forum. Not a big contributor, but a big reader of this forum, and today I want to share the story of my love for sports and math, and what came out of that. I am a mathematician myself, with degree in Combinatorics & Optimization, and at the same time a big football fan. That led me to discover and start to admire Betfair, a sports exchange that most punters already know. With time, I've realized the huge potential that lays behind it, where simply with your smarts you can make money. I've started to play around with different mathematical models that I've build for horseracing and football. That led me to different "discoveries" and realizations about Betfair markets. One interesting realization was the fact that football betting has a vast, and unknown to most, potential for optimizing bets across multiple markets... That's where it might get a bit complicated, but you are a smart crowd, and I am sure you can follow my train of thoughts here. An average football game has dozens of different markets. Examples of the market are: Match Odds, Over/Under x Goals, Correct Score, Both Teams to Score, and so on. Every one of those is a separate market on which you can bet independently. Popular games can have more than 60 different markets. What many do not realize is that many of those markets overlap. By that I mean, the outcome on one market will imply certain outcome on another market. For example, betting that there will be Under 0.5 Goals will imply that Both Teams will NOT Score, it will also imply a Correct Score of 0-0. And this is very basic example of one overlap, and there are hundreds of such overlaps, some of which are very complex and involve many different markets. But if different bets on different markets represent the same outcome, which one is more profitable? Which odds are better? For example, betting that there will be Under 1.5 goals scored, is the same as backing scores 0-0, 1-0 and 0-1 on Correct Score market... Most would simply bet on Under\Over market, but does it have better odds than backing 3 separate Correct Scores? You can take a calculator, or open Excel and calculate it in few minutes, but that's not a proper way to do it, and this is only one overlap out of hundreds. There is no way for human to calculate in timely manner all possible overlaps on all possible markets to find a best possible way to bet. That's when I realized that this is a perfect opportunity to apply mathematical optimization to. For few months, I've been building and polishing a mathematical model that would incorporate all possible football markets and overlaps between them. The idea was to have a model that would analyze all possible markets and their prices and come up with the most optimized way to place bets (think "should I bet on Under 1.5 goals or bet on 0-0, 1-0, 0-1? Which one is better?" but hundreds of times more complex). The result was a completely new way of football betting on Betfair. My model would wrap all separate Betfair markets into one huge market, and create a new layer over it, with one simple input method: you choose a bet amount, and pick scores that you want to win, break-even and lose on, and the model will calculate and place bets across all available markets achieving the maximum possible win. I know that this part might be especially confusing, since it presents a completely new way to bet on football. Simple example: Man U playing against Everton in Manchester. I want to win on scores 1-0, 2-0, 2-1, 3-1, and 1-1. I want to break-even (get my money back) on scores 0-0, 1-1, 0-1, and I am willing to lose 20 pounds on all other scores. My model would analyze all markets and my input and would tell me that my maximum win would be let's say 14 pounds (on all winning scores that I have picked), and to achieve it, 13 bets will be placed on 6 different markets. If I were happy with those numbers, it would place those bets for me. Then I made it a bit more flexible, where I could distribute the weight between different scores, for example if I want to win as much as possible (100%) on score 1-0, but I am ok with winning half of that on score 3-1 (50%), or even 10% of that max win. Or what if I am ok with losing 20 pounds on score 0-4, but I only want to lose 5 pounds on score 1-2. That made it even more customizable, but still kept it under one simple input interface. The result was a surprisingly fun way of betting on football. No more going through different markets, thinking where I should bet... Just analyze the match, think about which scores could probably happen, pick winning and break-even scores and optimize. I later added a lot more math on top of it, to automate and analyze markets even more, but I will not go there this time. Now this is the only tool that I use to bet on football. I later realized that there is no harm for others to know and use the same system, because the key ingredient here is your football knowledge, which in this case is your input (winning and break-even scores), and the model itself only optimizes your input to guarantee the placement of best possible bets. And you cannot dilute the winning system by going public with this system, because the system doesn't provide you one, your football knowledge and your input is the winning (or losing) system here. So I decided to build a Betfair application that anyone can use. I hired a developer and got official Betfair Vendor certification. Now I am trying to share it with everyone, because I truly believe this system provides the smartest way to bet on football. Being an honest guy, I can say that this post has twofold purpose. First, I believe the system that I developed will be beneficial for anyone betting on football, it does something no other system is currently doing. Secondly, I will not lie, there is a self-interest in it. Developing a Betfair certified application takes time, money and effort. Even though the system is free to try, it is still a paid system, but I honestly believe that if used properly (and smartly), the surplus amount that the system will optimize for you will exceed the cost of using the system. Due to the second point, and knowing the rules of the forum, I will refrain from posting a link, or even mentioning the name of the application. Even though, I've tried to contact admins of the forum in regards to conditions under which I can create such a thread with a link in it... I haven't heard anything back. Not sure why. So to stay in line with the topic of this forum (Systems & Strategy), I would like to discuss with you the proposed system, approach and any recommendations you might have to improve it. I understand that you might have questions about the system, so if needed, I am willing to explain more, to start a meaningful conversation. My name is Greg by the way. Let’s bet smart

[Poisson. Dixon Coles approach]

Re: Poisson. Dixon Coles approach Why would you want to beat bookies when you have such a great invention as Betfair? All bookies cripple your abilities on what can you do, and how can you bet to the point that it is almost impossible to make long-term profit with them. Betfair on the other hand is a level field for everyone involved, and the game is simple - the smartest takes the money of the dumbest (and pays 5% commission on it :)), that is why information gives you advantage, and Poisson is a great piece of information that can be used against those that are less smart in order for you to take their money. And don't forget that bookies goal is not to predict correct odds, but to balance their books in order to guarantee their profit. So often they intentionally over value or under value some results to achieve the balance. Also, bookies are known to do the so called Favourite-longshot bias (http://en.wikipedia.org/wiki/Favourite-longshot_bias). I will follow advice that was given to me and will start to post some Poisson probabilities for certain matches over here, with possibly even some picks, just for the fun of it.

Finding a good model though is not too difficult but finding a winning strategy is harder.

Those are the golden words. Cannot agree more.

[Poisson. Dixon Coles approach]

Re: Poisson. Dixon Coles approach

That's what I said. They are not independent but in multiplying them together to achieve a score it is assumed they are independent.

Sorry. Misread your message.

[Poisson. Dixon Coles approach]

Re: Poisson. Dixon Coles approach

Sounds similar to www.football-bet-data.com. They give predicted odds on over under' date= 1X2, both teams to score and also predict the final score and then show the average and max odds available. Did you come across that via google?

Yes, I use their Data Archive service for raw historical data. And I've seen their prediction services, and I bet that they use Poisson in some shape or form. The main difference is that they don't provide Correct Score odds (at least not in easily accessible form). Key element in my own strategy, and the only data you actually need (if looking for Poisson probabilities), since with that you can easily calculate all O\U, 1x2 and other markets. And I am not sure which variation of Poisson(if any at all) they use.

[Poisson. Dixon Coles approach]

Re: Poisson. Dixon Coles approach

The main problem of the method is that it uses two poison distributions (for number of goals each team scores) and multiplies them together as though they are independent when they clearly are not.

It does seem like that on a surface, but in the core is not true. Yes, you do multiplication of two Poisson distributions, but a key input of every Poisson is goal expectancy. And goal expectancy of a home team = attack rate of home team * defense rate of away team * home field advantage And goal expectancy of away team = attack rate of away team * defense rate of home team. From that, we clearly see that Poisson distributions are not independent since we use data of both teams in every Poisson. That is, goal expectancy of Wigan against Stoke will be higher than the same against Arsenal.

A further issue is that the same model won't work across leagues. I found this with all my models which i why i have produced league specific models

Yes, separate model should be build for every league, since home advantage and correlation factors are different for every league. From a summary of Dixon Coles paper: Maximum likelihood estimates are shown to be computationally obtainable, and the model is shown to have a positive return when used as the basis of a betting strategy.

[Poisson. Dixon Coles approach]

Re: Poisson. Dixon Coles approach Just an observation. Converted my O/U 2.5 probabilities for Inter - Parma match into odds and got the following Over 2.5 goals = 55.226% = 1/0.55226 = 1.81 Under 2.5 golas = 44.774% = 1/0.44774 = 2.23 Current Betfair odds: Over 2.5 goals = 1.81 Under 2.5 golas = 2.22 A good indication on how accurate the properly calculated Poisson can be.

[Poisson. Dixon Coles approach]

Re: Poisson. Dixon Coles approach Methuselah, froment, thanks for your reply. In short. Poisson distribution provides a probability that a give score will happen. Poisson function requires an input of goal expectancy for every team involved in a game. Goal expectancy is calculated using attack and defense rate of each team and home field advantage factor. There are different approaches in calculating those values, Dixon Coles approach being the one that is praised the most for its efficiency. Simple Poisson distribution is known for incorrectly calculating probabilities for low scores (0-0, 1-0, 0-1, 1-1) and that's were Dixon-Coles proposed incorporating a correlation factor that fixes that problem... I've realized that I just started to mumble math stuff. It is not an easy stuff even for mathematician, for a non-mathematician it is very complex. This Wikipedia article explains a little about statistical football prediction in general http://en.wikipedia.org/wiki/Statistical_association_football_predictions As to the "subscription based" and "give us your picks". Yes, the idea is to do it on a subscription basis, since it involves quite a bit of work to gather information and calculate results, and since, in my opinion it provides a lot of value to any strategy. The main point, that I think i didn't get out clearly is that it is not a strategy. I would call it a valuable information that could be used for a great profit in capable hands. It is up to the individual on how to use it. I will provide an example on what data am I talking about. Inter - Parma. Serie A. December 8. [TABLE=width: 512]

[TR] [TD]Score[/TD] [TD=colspan: 2]Probability[/TD] [TD]Score[/TD] [TD=colspan: 2]Probability[/TD] [TD]Score[/TD] [TD]Probability[/TD] [/TR] [TR] [TD]0-0[/TD] [TD=align: right]6.830%[/TD] [TD][/TD] [TD]4-2[/TD] [TD=align: right]1.424%[/TD] [TD][/TD] [TD]2-6[/TD] [TD=align: right]0.025%[/TD] [/TR] [TR] [TD]0-1[/TD] [TD=align: right]4.973%[/TD] [TD][/TD] [TD]5-0[/TD] [TD=align: right]0.788%[/TD] [TD][/TD] [TD]0-7[/TD] [TD=align: right]0.003%[/TD] [/TR] [TR] [TD]0-2[/TD] [TD=align: right]3.532%[/TD] [TD][/TD] [TD]5-1[/TD] [TD=align: right]0.890%[/TD] [TD][/TD] [TD]1-7[/TD] [TD=align: right]0.005%[/TD] [/TR] [TR] [TD]0-3[/TD] [TD=align: right]1.329%[/TD] [TD][/TD] [TD]5-2[/TD] [TD=align: right]0.502%[/TD] [TD][/TD] [TD]2-7[/TD] [TD=align: right]0.004%[/TD] [/TR] [TR] [TD]1-0[/TD] [TD=align: right]8.494%[/TD] [TD][/TD] [TD]6-0[/TD] [TD=align: right]0.232%[/TD] [TD][/TD] [TD]4-3[/TD] [TD=align: right]0.536%[/TD] [/TR] [TR] [TD]1-1[/TD] [TD=align: right]12.322%[/TD] [TD][/TD] [TD]6-1[/TD] [TD=align: right]0.262%[/TD] [TD][/TD] [TD]3-4[/TD] [TD=align: right]0.343%[/TD] [/TR] [TR] [TD]1-2[/TD] [TD=align: right]6.229%[/TD] [TD][/TD] [TD]6-2[/TD] [TD=align: right]0.148%[/TD] [TD][/TD] [TD]4-4[/TD] [TD=align: right]0.151%[/TD] [/TR] [TR] [TD]1-3[/TD] [TD=align: right]2.343%[/TD] [TD][/TD] [TD]7-0[/TD] [TD=align: right]0.058%[/TD] [TD][/TD] [TD]5-3[/TD] [TD=align: right]0.189%[/TD] [/TR] [TR] [TD]2-0[/TD] [TD=align: right]8.623%[/TD] [TD][/TD] [TD]7-1[/TD] [TD=align: right]0.066%[/TD] [TD][/TD] [TD]6-3[/TD] [TD=align: right]0.056%[/TD] [/TR] [TR] [TD]2-1[/TD] [TD=align: right]9.733%[/TD] [TD][/TD] [TD]7-2[/TD] [TD=align: right]0.037%[/TD] [TD][/TD] [TD]7-3[/TD] [TD=align: right]0.014%[/TD] [/TR] [TR] [TD]2-2[/TD] [TD=align: right]5.493%[/TD] [TD][/TD] [TD]0-4[/TD] [TD=align: right]0.375%[/TD] [TD][/TD] [TD]6-5[/TD] [TD=align: right]0.053%[/TD] [/TR] [TR] [TD]2-3[/TD] [TD=align: right]2.066%[/TD] [TD][/TD] [TD]1-4[/TD] [TD=align: right]0.661%[/TD] [TD][/TD] [TD]6-4[/TD] [TD=align: right]0.016%[/TD] [/TR] [TR] [TD]3-0[/TD] [TD=align: right]5.069%[/TD] [TD][/TD] [TD]2-4[/TD] [TD=align: right]0.583%[/TD] [TD][/TD] [TD]3-5[/TD] [TD=align: right]0.077%[/TD] [/TR] [TR] [TD]3-1[/TD] [TD=align: right]5.722%[/TD] [TD][/TD] [TD]0-5[/TD] [TD=align: right]0.085%[/TD] [TD][/TD] [TD]3-6[/TD] [TD=align: right]0.015%[/TD] [/TR] [TR] [TD]3-2[/TD] [TD=align: right]3.229%[/TD] [TD][/TD] [TD]1-5[/TD] [TD=align: right]0.149%[/TD] [TD][/TD] [TD]3-7[/TD] [TD=align: right]0.002%[/TD] [/TR] [TR] [TD]3-3[/TD] [TD=align: right]1.215%[/TD] [TD][/TD] [TD]2-5[/TD] [TD=align: right]0.132%[/TD] [TD][/TD] [TD]4-5[/TD] [TD=align: right]0.034%[/TD] [/TR] [TR] [TD]4-0[/TD] [TD=align: right]2.235%[/TD] [TD][/TD] [TD]0-6[/TD] [TD=align: right]0.016%[/TD] [TD][/TD] [TD]4-6[/TD] [TD=align: right]0.006%[/TD] [/TR] [TR] [TD]4-1[/TD] [TD=align: right]2.523%[/TD] [TD][/TD] [TD]1-6[/TD] [TD=align: right]0.028%[/TD] [TD][/TD] [TD]5-5[/TD] [TD=align: right]0.012%[/TD] [/TR] [/TABLE] [TABLE=width: 192] [TR] [TD=width: 64]Over/Under[/TD] [TD=width: 64] Over[/TD] [TD=width: 64] Under[/TD] [/TR] [TR] [TD]0.5[/TD] [TD=class: xl156, align: right]93.170%[/TD] [TD=class: xl156, align: right]6.830%[/TD] [/TR] [TR] [TD]1.5[/TD] [TD=class: xl156, align: right]79.703%[/TD] [TD=class: xl156, align: right]20.297%[/TD] [/TR] [TR] [TD]2.5[/TD] [TD=class: xl156, align: right]55.226%[/TD] [TD=class: xl156, align: right]44.774%[/TD] [/TR] [TR] [TD]3.5[/TD] [TD=class: xl156, align: right] 32.866%[/TD] [TD=class: xl156, align: right] 67.134%[/TD] [/TR] [/TABLE] [TABLE=width: 143] [TR] [TD]Inter Win[/TD] [TD=align: right]50.898%[/TD] [/TR] [TR] [TD]Draw[/TD] [TD=align: right]26.087%[/TD] [/TR] [TR] [TD]Parma Win[/TD] [TD=align: right]23.015%[/TD] [/TR] [/TABLE] Formatting is a bit off, still figuring out the forum functionality. Probabilities could easily be converted to decimal odds by doing 1/probability. So Inter Win odds as per this calculations are 1/0.50898 = 1.96. Current Betfair odds for Inter win is 1.76 What is given is purely scientific Poisson distribution calculated by Dixon Coles approach. My calculations follow the mentioned paper word by word. Nothing less, nothing more. As I have stated before, how to use this information is up to the individual. You can start at simple Over/Under 2.5 goals and look for over\under priced markets on Betfair, and go to as far as complex multi market analysis and Correct Score betting. I hope this clarifies my original post a bit.

[Poisson. Dixon Coles approach]

Hello to all. I am new to the community, and it is actually my very first post on this forum. I am a mathematician myself, and recently had started to get into football modeling. I was playing around with Betfair for years now, but just recently had concentrated on it full time. I am fascinated by the scope on how deep math could be applied at Betfair markets. When researching football modeling I had stumbled upon a highly regarded Dixon, Coles (1997) paper "Modelling Association Football Scores and Inefficiencies in the Football Betting Market" which applies time factor and very important correlation factor for low scoring games to Poisson regression. It took me some time in figuring out how to translate those formulas to real numbers that will tell me what is the chance of a score x-y happening in a game N. I did it at the end, and now have a system that can generate a probability of all possible scores (from which a lot of other probabilities such as 1X2, Over\Under and so on, can be generated) for all major leagues. Those Poisson values are now play a critical role in my overall strategy, that forecasts a return of 5-7% (only time will tell a real value). When working on it, I was looking for resources that will provide me concrete help in getting those values, with little luck. And that is when I had an idea of building a subscription based website that will provide detailed and scientifically backed probabilities (for 3 Correct Score markets, Match Odds and Over\Under markets) for every match of every major football league. It can be used either as part of your strategy, or as an extra confirmation check. There are numerous uses for such data. I realize that not all punters have an in-depth math knowledge that is required for getting those values, and that is why I think such a website would be very helpful for many. Why I am writing this? Well, since most of my research and development I did on my own, with no contact to "outside" world (i.e the community), I am not sure if such a service would be useful and needed. Not sure if such a service already exists (which will mean that my Google skills aren't as great as I thought). Not sure, on maybe everybody and thier uncle had already figured it out and successfully using Dixon Coles Poisson, and I am here playing an old record. What are your thoughts?