Saturday 28 March 2015

Over / Under strategy for English Premier League

First I want to report what was the result of Chi-Square testing for my over/under strategy. For 272 matches which qualified for the strategy, test has shown us that there is slightly over 5% chance that my strategy is the result of luck (normal distribution) rather than edge.
That doesn't sound like a lot but in statistics it is actually on the edge of statistical relevance.
But we have to take in the account that this was a simple Chi-Square test which doesn't take in the account what is the edge for each individual bet!
So for example it doesn't take in the account when fair odds are 1.4 and market odds are 1.9 and Kelly bet is 39% of the bank or when indicated fair odds are 1.4 market odds are 1.6 and we should bet only 20% of the bank. It looks only at the average edge and treats both tips only either as a win or loss.
So taking this in the account and adjusting results for edge differentiation we can be confident that actual chance of no statistical edge in our strategy is under 1%.


On 15th of March we had first bet on the match which qualified for our strategy. Indicated bet was on over 2.5 with odds of 1.83 between Man U vs Tottenham and already after 34 minutes of play when Man U increased their lead to 3-0 the bet was settled as a win.

I write these posts at least once per two weeks, primarily for myself as a part of my accountability. 
But I was asked to share more about my bank management. So from now on I will not only post tips for this strategy but also exactly how many units you should bet.

I use Kelly criterion formula for this betting strategy.
So for example last tip was on over 2.5 at odds of 1.83 and according to Kelly criterion bet had such an edge that it was worth 0.36 (36.1%) of our starting bank.You can do partial Kelly bet to decrease risk to 1/4 or more as I do.
How do I calculate my bet?
I decided that starting bank for this will be 3000€ and I will always bet 1/4 of full bet according to Kelly criterion.

So 3000/100*36.1 = 1083€ which would be the full bet according to Kelly criterion.
I divide that by 4 which in my case gives me bet of 270.75€ I should risk.


You can see from my P&L statement from a certain bookie that my bet for this match was 250€ and the corresponding profit was 207,98€. I did bet another 21€ at another bookie with a profit of 17.64 for a total bet of 271 euros.

Starting bank: 3000€
Total profit on 15/3/2015: 226€
ROI: 83.3%
Final bank on 15/3/2015: 3226€

Remember, ROI will drop a lot with a time BUT our bank will also grow. 
One more thing: the odds before the match actually moved out from 1.83 to 1.95 on Betfair. I don't know the reason of the movement but remember this: one thing is odds movement and another thing, completely different, is actual chance of winning!
So don't expect that the odds will always come down on this strategy, they might go in our favor and make the edge even bigger.
I will always calculate the edge and amount to bet at least one day in advance so there is still a lot of time for bet placement.

Also I'm always interested in valuable edges and strategies!

All the best!

Saturday 14 March 2015

Looking for the edges

In last two weeks I made quite a good progress. I did some further statistical studies and testing and I have found 2 solid tipsters which I started follow.

Tomorrow will be there the first match (Man U - Tottenham) which will qualify for my own betting strategy I was working on recently. According to my model fair odds for over 2,5 should be in 1.5-1.6 range, they are 1,83 instead so I will take an advantage.

What kind of betting management will I use?
I will go for partial Kelly stake which means I will bet about 1/3 of what full Kelly stake would be.

My plan for week ahead is to find some more edges, especially external which are much easier to find than going through backtesting. When I exhaust external sources I will dig through the stats.

There is so much opportunity in this industry, you just have to know what you want to do, do your work, be disciplined and the rest will take care of itself.
Good luck