Originally Posted by
Sinister Cat
Okay I fixed that link. Using the method in that thread, assuming everything is -110, I got around an 88% chance that you are profitable going forward.
Spot on results, but I'd phrase the conclusion differently.
There's a roughly 1-88%=12% probability that a handicapper no better than breakeven would see results of this magnitude or better.
Anyway, here's how the numbers would breakdown:
Obtaining approximate results in Excel using the methodology outlined above:
Z = (161/1.1 - 127) / sqrt(288*10/11) ≈ 1.1967
p(z < Z) = NORMSDIST(1.1967) ≈ 88.43%
Obtaining exact results in Excel using the binomial distribution:
p = BINOMDIST(161-1,288,52.381%,1) ≈ 87.25%
Of course, just as Peep says, if you're backfitting and/or looking at some nonrandom subset of your actual betting history then these results would be effectively meaningless.