System Selections 25/11/2008 (Results) and 29/11-1/12/2008

It's another one of those All Inclusive posts: it has an update with the midweek results, the weekend's picks and another summary table to monitor performance. So without further ado:

Some good midweek results increasing the profit. Hopefully it will continue over the weekend:

Finally, here are the so far results with 16 pending bets:

System Selections 25/11/2008

The great thing about English football is that it's almost every day... So here are tonight's set of picks according to the system.

Hoping for a profitable night of (virtual) betting!

System Selections 21-24/11/2008 (Results)

A small loss for the system but nothing too serious.

There are additional matches this evening so the system's picks will be posted later today.

System Selections 21-24/11/2008

It was a pretty busy week, so the analysis promised in my previous post did not materialise... Hopefully it can be posted some time next week, thus taking into account this weekend's selections:

System Selections 15-16/11/2008 (Results)

Back into positive territory for the system, carrying forward the recent good form. Long may it continue!

There are midweek international matches which will hopefully give me the chance of updating the thread with a breakdown of these figures, by type of bet (H/D/A) as well as by competition (Premier League, Championship, League One and League Two). Some interesting figures will be coming up...

System Selections 11/11/2008 (Results) and 15-16/11/2008

The midweek pick did not materialise, but there's a whole batch for the weekend. Let's hope that the system's recent form continues!

Fingers crossed!!

System Selections 8-9/11/2008 (Results) and 11/11/2008

Another weekend passes by without me being able to put these selections up on time. As mentioned before they are verified at Punters Lounge, however available time is sometimes not enough... It's a shame really as they proved to be reasonably successful, managing to turn the recent losses to small gains. Anyway, here are the results (for completeness sake):

There is one League One match tonight which incidentally qualifies as a system bet. Come on Yeovil!

The system performance table will be updated tomorrow. Good luck to everyone!

Evaluating a Betting System's Performance (Part One)

It's been quite a while since I last had a blog entry which was not a system update so here is (hopefully) some food for thought.

Surfing the Internet, visiting various betting websites and forums (or should I say fora), I've stumbled across countless betting systems and strategies. These systems consist of not only the tipping part but also different, and sometimes quite elaborate staking plans. An obvious question which arises is "How does one compare these systems?"

I have always been a firm believer that forecasting / prediction models, irrespective of the way their predictions are formulated, should be monitored, evaluated and adjusted; in other words they should be judged. Only by judging a forecasting tool one can hope to improve it. What I am not exactly sure, and please if you have any views do share them, is the way this should be done. You see, everybody looks at the yield and of course this is a measure of how good the system is with this particular set of results. But it's also important to acknowledge that part of a system's performance is due to luck. In other words, if it was possible in a way to re-create all matches in a season, with the same parameters as at the time of the match, what would the system result in, given that not all matches would end up with the same outcome? Is there a way to utilize statistical theory in such a way to account for this uncertainty an create a more robust measure than yield itself? The million dollar question, I guess.

Internet research on this issue leads quite often to the notion of χ²-testing. The idea behind this test is to compare, with some sort of statistical confidence, the number of a system's actual (or observed) winners to the corresponding expected number. For example 15 bets at even odds would yield an expected number of 7.5 winners, but the actual number of winning bets might be 9. Is this sufficient evidence to suggest that the system is performing better than what would be expected by sheer chance? What if the actual winners were 10? 12? All 15?

Well, the χ²-test provides a way to measure this by looking at the probability of achieving the observed result (i.e. the number of actual winners) or a better result by chance. If for example there is a 30% probability of hitting 9 winners or more (given the odds at which the bets were taken) out of 15 simply by chance then the system is not performing necessarily well. As soon however, as this figure is reduced, it means that the system is hitting the winners not necessarily by chance but rather by exploiting value through mis-priced matches. Anyone who has studied any introductory statistics course will tell you that the figure that statisticians are interested in, when testing hypotheses, is the 5% so in effect, according to this test, one would be happy if the χ²-test returned a probability less than 5%.

My personal opinion is that the χ²-test is not necessarily a good indicator of whether the system is performing well. All it does is to check whether the number of winners is significantly higher than what one would expect by sheer chance, but it does not consider the odds at which these winners were picked. What if a system's winners came at very low odds, whereas the system underperformed in the high range of odds. This could lead to a case of achieving a high (as compared to the expected) level of winners, yet the yield could be very low or even negative! Some consolation, I hear you say ... Of course the opposite could also be true: a few longshot winners could be enough to lead to a positive yield yet the number of correct picks could be below the expected number. [For the doubters amongst you that such a case is not as implausible as it may sound, feel free to check the relevant discussion on Punters' Paradise forum.]

The search must carry on. In Part Two of this post (to be posted some time in the near future), I'll look into different ways of assessing whether one has a profitable system and to evaluate its performance. Until then take care!

System Selections 1-3/11/2008 (Results)

The weekend saw a much needed improvement to the system, although we are still in the red. Hopefully, this profit was a sign of things to come rather than a false dawn. Only time will tell!

System Selections 28-29/10/2008 (Results) and 1-3/11/2008

Not a good midweek set of matches with a few late winners in the Premiership turning draws into wins, and profits into losses!

We proceed quickly to the weekend picks and an update will follow on Monday. Hopefully there will be better times ahead!