Gambler’s Fallacy and the Regression to the Mean

Re:Gambler’s Fallacy and the Regression to the Mean by compiler-guy on Friday January 07, 2022 @11:58PM (#29848756)

Strangely, ten reds in a row is not particularly good evidence of an unfair wheel.

For an American wheel, the odds of red in a single spin is 18/38= 0.4737. So ten in a row is 0.4737^10, which is about 0.0005689.

So one should expect five or so such sequences in ten thousand spins. Or one in every two thousand spins.

If a casino spins its roulette wheel 200 times a day, you would expect to see a sequence of ten reds in a row every ten days. If the casino runs ten roulette wheels, it's an every day occurrence.

Low probability events happen regularly with enough samples.

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Re:Gambler’s Fallacy and the Regression to the Mean by bryanlarsen on Saturday January 08, 2022 @09:11AM (#29851821)

Depends on the situation. At a well-regulated, long-lived casino with lots of tables, it's not good evidence.

But if you see it run by carnies at the county fair where the wheel will be gone tomorrow?

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