The emergence of betting exchanges has allowed the public to keep a greater share of betting turnover and allowed a knowledge of sports betting markets to be rewarded. In this post I also cover the concept of value betting and probabilities.

Chance and probabilty

All us punters have one thing in common. We are all trying to beat the bookie. Or, with the emergence of betting exchanges, the guy on the other side of the bet. For the average punter betting is just entertainment, a few quid on a Saturday at the bookies or between friends in the pub. A detailed assessment of the likely outcome is given only moderate consideration. The entertainment is most often in making the bet and the excitement of having a few quid on whilst watching the event. Collecting the winnings of course also has its pleasures!
Continued

It’s a nervous weekend of games after last week’s losses.  Although 2 losing weeks on the trot is not an unknown for the model it is a remote event and one I do not want to see played out this weekend.  Therefore I have more than my fingers crossed that we get back on track with this weekend’s selections.

I have made some changes to the algorithm, albeit minor.  It was just a bit of tweaking of the input variables which has resulted in improved performance over all seasons and more importantly, this season. 

The best value today is backing Birmingham away offering 90% value at Bolton whereas the closest odds produced by our model versus the market is Arsenal with just 4% value.   One point of interest is the model lays Portsmouth which is the first time in recent times the market odds have been priced too short to offer value in backing Pompey.  This is likely due to Portsmouth’s loss last week combined with the very high rating the model has for Liverpool.

DATE HOME AB Odds Ex Odds Value  AWAY AB Odds Ex Odds Value
22/12/07 Arsenal 1.49 1.55 4%  Tottenham 6.44 7.80 21%
22/12/07 Aston Villa 1.31 2.04 56%  Man City 9.71 4.80 -51%
22/12/07 Bolton 3.55 1.88 -47%  Birmingham 2.64 5.00 90%
22/12/07 Fulham 1.46 2.22 52%  Wigan 6.73 3.90 -42%
22/12/07 Liverpool 1.33 1.58 19%  Portsmouth 9.12 7.80 -14%
22/12/07 Middlesbrough 2.01 2.30 14%  West Ham 3.91 3.50 -10%
22/12/07 Reading 1.32 1.88 42%  Sunderland 9.29 5.20 -44%

It just goes to show how misleading statistics can be.  Reading win 3-1 at home and yet Liverpool had by far most of the play.  Portsmouth win 1-3 away and yet it was Villa with all the chances until they went 2 goals down, opened up at the back and then scored themselves!  The result in these games therefore do not reflect the performance of the teams.  That’s why when picking selections you need to do more than just look at a teams last result.

Even the return over a week (11 games this week) can be skewed by random outcomes.  A month is a better assessment of performance. So, there’s the rider, now on to Sunday’s games.

I’m not confident about these games.  Though that is often the case.  The Algorithm rates Spurs highly though their league position and results really do not support it.  Man City are also flying high in the league and yet we have 73% value on Spurs and -63% on Man City.  Does this give a clue to the decay of form I am using or are Spurs all flare and no punch.  Sure, if Spurs win and we look back at the result in years to come it will be no suprise but right now it just seems far fetched. 

It’s also annoying that prices have moved against me since yesterday, i.e. market prices have come closer to mine which means less value. Ho hum.  I need to keep reminding myself of the long term.

DATE HOME AB Odds Ex Odds Value  AWAY AB Odds Ex Odds Value
09/12/07 Blackburn 1.61 1.95 21%  West Ham 4.76 4.80 1%
09/12/07 Bolton 1.51 1.98 31%  Wigan 5.39 5.00 -7%
09/12/07 Middlesbrough 9.13 8.00 -12%  Arsenal 1.90 1.58 -17%
09/12/07 Tottenham 1.22 2.10 73%  Man City 11.69 4.30 -63%