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The math of shuffling cards almost brought down an online poker empire

(www.scientificamerican.com)
97 points indigodaddy | 1 comments | 05 Sep 25 22:50 UTC | HN request time: 0.202s | source
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sneak ◴[07 Sep 25 02:05 UTC] No.45154725[source]▶
> Card dealers create a unique deck with each shuffle, something computers cannot replicate

This is entirely, unequivocally false.

Shuffling as an algorithm to implement is easy to fuck up, but if you use a good one and a true RNG source, computers can shuffle better than humans - just as randomly, and many orders of magnitude faster.

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smallerize ◴[07 Sep 25 02:12 UTC] No.45154759[source]▶
I think the RNG source is the point here. It's not as impossible as stated, but you have to put some work in to get a good one.
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awesome_dude ◴[07 Sep 25 02:15 UTC] No.45154786[source]▶
Go (and probably other languages) has the Fisher-Yates algorithm for shuffling

https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle

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genghisjahn ◴[07 Sep 25 02:33 UTC] No.45154868[source]▶
It’s comments like this that keep me coming back to HN. I’d never heard of this before.
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andrewflnr ◴[07 Sep 25 03:14 UTC] No.45155096[source]▶
Really? It repeats a point from the article, and in so doing utterly misses the point of the comment it's replying to. Fisher-Yates is at least not broken, but it can only be as good as the underlying RNG.
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awesome_dude ◴[07 Sep 25 03:43 UTC] No.45155213[source]▶
Go has a cryptographically secure RNG now, I wouldn't be surprised if it's being used for the shuffle.

Also, I'm keen to see what shuffle algorithms you know of that aren't susceptible to RNG issues

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1. andrewflnr ◴[07 Sep 25 13:46 UTC] No.45158103[source]▶
> I wouldn't be surprised if it's being used for the shuffle.

That would certainly be a good thing to check before using Go's shuffle for real-money poker games. I wouldn't take it for granted.

> Also, I'm keen to see what shuffle algorithms you know of that aren't susceptible to RNG issues

There are not and cannot be any such algorithms. That's the entire point of this thread. Fisher-Yates is necessary but not sufficient. You either have sufficient random bits for your shuffle or not.