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by bitshiftfaced 1046 days ago
> as we all know you can't flip a coin many times without tails showing up.

We don't all know that. There's an ever-decreasing but nonzero probability that you will keep getting heads.

2 comments

The probability that the next N flips will all be heads is small and gets smaller the larger N is.

But the probability that the next flip is heads is .5 no matter how many of the previous flips were heads :)

> There's an ever-decreasing but nonzero probability that you will keep getting heads.

But with enough flips, the odds getting heads on all of them comes close enough to zero that they are effectively zero.

"Effectively zero" times infinity is infinity. Infinity is like... really big.
Oh, I wish I could find it, but there's an excellent video by a mathematician explaining why an infinity doesn't work in your favor here. IIRC, it's because as the number of throws approach infinity, the odds also approach being infinitesimal, and you'll still lose.
This paradox is famously a case where the expected value of the game is infinite.