wadood
05-09-10, 07:17
There are many good tipsters in this forum and probably in some others.
But the method of scoring is not scientific.
A uniform method is needed as well as a scientific one to measure their performences.
The method to achieve this is every tipster should give his predictions as percentage probabilities like this:
match A: 70% - 20% - 10%
match B: 45% - 35% - 20%
The result he wants us to bet could perhaps be indicated by bold, or red, or underlign.
What is the method of calibration then ?
Suppose we have two forecasters as follows:
Tipster 1:
match A: 70% - 20% - 10%
match B: 45% - 35% - 20%
match C: 15% - 30% - 55%
match D: 60% - 30% - 10%
Tipster 2:
match A: 90% - 05% - 05%
match B: 30% - 30% - 40%
match C: 20% - 40% - 40%
match D: 70% - 25% - 05%
and suppose the result line is 1-X-2-X
Then tipster 1 score is = (0.70 x 0.35 x 0.55 x 0.30 ) ^ (1/4) = 0.4484 or 44.84%
and tipster 2 score is = (0.90 x 0.30 x 0.40 x 0.25 ) ^ (1/4) = 0.4054 or 40.54%
Because the series of numbers thus obtained may be long we use logs:
score = exp [ SUM OF ( log probability ) / no of matches with known result ]
This is the scientific method so we know who are the best tipsters without dispute.
Effectively we are determining what might be called "a mixed mean Bernoulli number" for each one. Every match is a Bernoulli probability experiment after all and what the tipster does is strive to approach certainty with his predictions. Certainty lies at infinity of course and requires all the predictions to be of the 100-0-0 type and all correct.
* It is quite possible and quite likely indeed that the same folks who are now nominated as champion tipsters will emerge as champions again, but we should be given a real figure of merit, using the above rigorous mathematical formularism, rather than ad hoc.
But the method of scoring is not scientific.
A uniform method is needed as well as a scientific one to measure their performences.
The method to achieve this is every tipster should give his predictions as percentage probabilities like this:
match A: 70% - 20% - 10%
match B: 45% - 35% - 20%
The result he wants us to bet could perhaps be indicated by bold, or red, or underlign.
What is the method of calibration then ?
Suppose we have two forecasters as follows:
Tipster 1:
match A: 70% - 20% - 10%
match B: 45% - 35% - 20%
match C: 15% - 30% - 55%
match D: 60% - 30% - 10%
Tipster 2:
match A: 90% - 05% - 05%
match B: 30% - 30% - 40%
match C: 20% - 40% - 40%
match D: 70% - 25% - 05%
and suppose the result line is 1-X-2-X
Then tipster 1 score is = (0.70 x 0.35 x 0.55 x 0.30 ) ^ (1/4) = 0.4484 or 44.84%
and tipster 2 score is = (0.90 x 0.30 x 0.40 x 0.25 ) ^ (1/4) = 0.4054 or 40.54%
Because the series of numbers thus obtained may be long we use logs:
score = exp [ SUM OF ( log probability ) / no of matches with known result ]
This is the scientific method so we know who are the best tipsters without dispute.
Effectively we are determining what might be called "a mixed mean Bernoulli number" for each one. Every match is a Bernoulli probability experiment after all and what the tipster does is strive to approach certainty with his predictions. Certainty lies at infinity of course and requires all the predictions to be of the 100-0-0 type and all correct.
* It is quite possible and quite likely indeed that the same folks who are now nominated as champion tipsters will emerge as champions again, but we should be given a real figure of merit, using the above rigorous mathematical formularism, rather than ad hoc.