Born At Midnight 10/1 with WilliamHILL
A/E : 2.3
EXP : 9.8
CHI : 11.4
CHI
Info:
The Chi Score tests the robustness of the system you have run. A Chi Score of above 4 shows a backing or laying system is robust
NOTE: The Chi Score is not meaningful unless the number of expected winners is above 5.
EXP
Info:
The number of winners the system is Expected to produce. Calculated from the odds of each runner converted to a % chance.
NOTE: The expected number of winners should be at least 5. This ensures you're sample size is big enough.
A/E
Info:
The A/E index indicates if a statistic is good or bad and is calculated as follows:-
A = Actual Winners
E = Expected Winners.
A is easy to calculate as it is the number of winners.
E is the total of all the probability or odds of winning for each horse based on the SP prices for each horses
e.g. If we have 100 horses who went off at 3/1 then we would expect 25 of them to win. The odds of a 3/1 shot is 0.25 so adding all 100 of those together = 25.
Once you have the expected number of winners then you just divide actual winners by expected winners to produce the A/E index.
An A/E index of 1.00 means the statistic is performing as expected, less than 1 and it is under performing and more than 1 and it is performing better than expected.
As a benchmark an A/E of 1.25 or greater would be very good and an A/E of 0.75 or lower would be bad.