[11thEarlOfMar]

One time, my wife and siblings had to choose from a number of heirlooms that had be left to them but not assigned. They are living around the planet, and the discussion came up about how to decide the order in which they'd select the items.

I came up with this: Each of them select a different stock market index. On the same calendar trading day, they choose two digits past the decimal. When the market's close, compare the two digits of the closing price of their chosen index to the two digits they selected and then choose heirlooms in the order of closeness.

It worked quite well. They were on board because they could make two selections in determining their order: Market and digits. Two of them could choose the same two digits if they wanted and still have different scores. No complaints.

Not random, but seemed fair to all.

[LVB]

This sounds like an excellent use case for the NIST Randomness Beacon (https://csrc.nist.gov/projects/interoperable-randomness-beac...)! Introducing my extended family to that would be… interesting.

[DalekBaldwin]

This is similar to how "numbers racket" lotteries in the early 20th century operated, so that players could trust that the outcome could not be rigged: https://en.wikipedia.org/wiki/Numbers_game#Gameplay

(The film "Force of Evil" is about a plot to nevertheless rig the outcome.)

[mcstafford]

One thing we seem to have discovered is that absolute randomness is harder than it might first seem.

Your idea combines what feels like a significant percentage of randomness while still having enough participation to rationalize buy-in.

It's tough to want to yield control of an important choice to a random number generator... though that's not an inaccurate description for this.

I like this as a perspective on "the illusion of choice". Part of me hates the phrase because I want to believe that I can take meaningful action.

[lisper]

Another possibility: hold a private auction among the siblings and give the proceeds to the favorite charity of the person who left the heirlooms. It's fair [1], honors their memory, and makes the world a better place all at once. Three-way win.

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[1] You can compensate for unequal economic situations by limiting the total amount that any one person can bid to a value that they can all afford.

[pwython]

This is one of the craziest, most convoluted approaches to randomness I've ever heard of. I love it. Personally, I would've just had a third-party roll a die to establish the order. If there's a tie, roll again. More than 6 siblings? Two dice. Fun for the whole family! (and would take just a few minutes)

[thrashh]

I don’t think the issue was the randomness.

I think it was avoiding trusting a third party.

[11thEarlOfMar]

Yes, thanks for prompting my memory. We needed an approach that put all five of the siblings on the same footing. Even a third party chosen by one of the five may not be trusted since the others may not know the party.

It was goofy, but satisfied them all without dissent. And it worked!

[oconnor663]

Keybase supports provably fair coin flips :)

[tromp]

> Not random

The least significant bits of a bitcoin PoW hash behave pretty randomly. You could either bet on a fixed future block height, or on the first block past a given future timestamp...

[lern_too_spel]

This just relies on the pseudorandomness of SHA-256. You can skip a lot of waste and use SHA-256 directly.

[tromp]

No; it relies on practically nobody being able to control what the SHA-256 is applied to.

[lern_too_spel]

That's actually very easy to control. Just pay a high transaction fee. The nonce comes from a PRNG that doesn't have to pass many randomness checks. Your proposal really is no more random than a counter based SHA256 PRNG except with an awfully high sample latency.