Re: Standard Deviation Question, How to do it?
Let me see if I understand. You entered four tournaments. In the first one 4% of the entrants were still alive when you went broke, 15% in the second, 33% in the third and 47% in the fourth (quit while you're still above median). Is this correct?
Then you want to compute standard deviation. I assume you want to predict a confidence estimate for future finishes. You have to make some assumptions to do this. Not just the usual ones about all finishes being independent and from the same distribution, but you need to guess the shape of the distribution of finishes. Normal is not appropriate, because you can't do better than 0 or worse than 1.
A power distribution is a common model, and easy to use. You assume that the probability of fraction X or less of the players finishing ahead of you is X^a for some a. Using your data suggests a = 0.2894. This imples a 67% chance of finishing in the top quarter, 82% chance of finishing in the top half and 92% chance of finishing in the top three-quarters. Of course given only four tournaments and the arbitrary model, I wouldn't put a lot of weight on these statistics.
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