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Kelly Can't Fail

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389 points jmount | 1 comments | | HN request time: 0.203s | source
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PaulHoule ◴[] No.42470752[source]
When I was a teen I discovered that I could always guess more than half the cards right using card counting to determine what color is more common in the deck. I programmed my

https://en.wikipedia.org/wiki/TRS-80_Model_100

to simulate it and it never failed. Recently I thought about it again and wrote a Python script that tried it 30 million times and... it never failed.

I've been thinking about what to do with it and came up with the options of (i) a prop bet and (ii) a magic trick, neither of which seemed that promising.

As a prop bet I can offer $1000 to somebody's $10 which is not the route to great prop bet profits, also I worry that if I make a mistake or get cheated somehow I could be out a lot of money. (Now that I think of it maybe it is better if I re-organize it as a parlay bet)

As a magic trick it is just too slow paced. I developed a patter to the effect that "Parapsychologists were never able to reliably demonstrate precognition with their fancy Zener cards, but I just developed a protocol where you can prove it every time!" but came to the conclusion that it was not entertaining enough. It takes a while to go through a deck which doesn't seem like a miracle, you will have to do it 7 times in a row to exclude the null hypothesis at p=0.01. Maybe somebody with more showmanship could do it but I gave up.

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jdhwosnhw ◴[] No.42473121[source]
That reminds me of my favorite algorithm, which can find the majority element in a list with any number of distinct entries while using O(N) time and O(1) space (provided a majority element exists). I sometimes pose deriving this algorithm as a puzzle for people, no one has ever solved it (nor could I).

https://en.m.wikipedia.org/wiki/Boyer%E2%80%93Moore_majority...

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1. barapa ◴[] No.42473561[source]
That is really cool