Have been playing with a system that has shown some great results so far, so have been lookig at a few of the tests that can be done to see if the results are luck or not. Now, I grabbed this chi test from an old post that angry pixie put up.
http://www.propun.com.au/racing_for...74&postcount=30

Can someone check that I have done this right? As I intend using betfair, for normalising the market I used 107%, as the markets generally run at around 102%, plus then adding on 5% for commission (not sure if thats a correct way to do it or not?)

Here are the results to date.

System base stats:
Bets:176
Winners:46
SR:26.7
Av div:4.94 (betfair)
Av div:4.33 (supertab)

And my attempt at the calculations:

Observed wins:47
Observed loss:129
expected wins:33.2
expected loss:142.7

Chitest result: 0.008374369

Running the same calcs for the TAB divvy I get:

Observed wins:47
Observed loss:129
expected wins:38.74
expected loss:137.26

chitest result:0.132905506


So if my calcs are correct, that would suggest that the chance that the results are down to luck is 0.8% (betfair), and 13.2%(tab)?

Could one of the gurus check if these are correct?

Cheers

Thinking about this more, I think I may have made an error with the betfair results. The divivdend shown there is the raw price, not with price with a 5% commission deducted. Getting a bit confused on whether using the raw divi, should the normalised market be 102 or 107%?

Hmmm, looks like I may have used the inccorect divis as it seems it should be teh average of all slections, not just winners. In this case the av divis should be:

Betafair:5.79 (raw price)
SuperTAB:5.04

Using the supertab price I get a Chitest score of:

0.000546

This seems far to small though so am thinking I have stuffed up somewhere.

That is plain wrong.

It should be average price of winners only.

Simply using a Binomial Confidence Limits calculator would show:


46/176 reduces to a strike rate of 19.81%.


So even at an average div of 4.94 your system would be considered unprofitable long term.

47/176 would be ~break-even.

Cheers JFC,
So given that, would you bin the system, or run more trials to get a better picture of what the actualy long term srtike rate would be?
Using the java stat page that I beleive you have linked to previously, if for example i enter 460/1760, I get a range of 24-28% (roughly) which would indicate a long term profit, if the divi holds up.