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Old 07-19-2005, 10:02 AM
SonnyJay SonnyJay is offline
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Join Date: Sep 2004
Posts: 4
Default Re: Mathmetically speaking

As a finance major who recently had to take an extensive statistics program, I'll present you something similar to an example that my professor gave me.

Suppose you're playing a game with your friend where you're flipping a coin, where you make $1 for each heads and you lose $1 for each tails. You will flip 50 times, take a break, then flip 50 more. Your EV for the day, obviously (I hope) is 0.

After 50 flips, you happen to be up $5. Now, given that you're up $5, what is your total expectation for the day at this point? It is $5, because you are already up $5 and flipping 50 more times at an EV of 0.

The "law of averages" that everyone thinks of is bogus, that a big upswing is sure to be followed by a big downswing. The real law to be concerned about is the Law of Large Numbers, meaning that as your sample size grows very large, your return will converge towards the EV.

You have played 1000 SNGs at an ROI that clearly is not sustainable, but that does not mean that a downswing is inevitable. Sure you may not maintain that ROI, but all that the Law of Large Numbers means is that as you approach 10,000 SNGs, 100,000 SNGs, and 1,000,000 SNGs, your ROI will begin to approximate your "true" ROI.

In the long run you'll likely win, just not at the rate you currently are winning.

-SonnyJay
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