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Comment by helterskelter | Hacker News Reader

I'm curious, and I figure you would know more about this than I do: when using real yarrow stalks for the I Ching, how do you split them into groups? I mean like, roughly equal? Don't think about it too much and just split? Just separating them into, say, groups where one group is just a single stalk doesn't seem random.

I guess it's a question of philosophy, either split into groups based off of your intuition, or aim for a truly random split in the pile.

Anyway, I wasn't sure if this is something that's a settled matter or what.

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OP here. This discussion is exactly why I implemented the Box-Muller transform!

You are right that humans don't split perfectly randomly (Uniform Distribution). We tend to aim for the middle but miss slightly.

In my code, I modeled this 'human splitting action' using a Gaussian (Normal) distribution centered at 50% of the pile, with a standard deviation. This simulates the user trying to split the stalks roughly in half, rather than just picking a random number from 0 to 49.

Interestingly, my Monte Carlo simulations showed that even with this human bias (splitting near the middle), the final modulo-4 probabilities remain stable. So the algorithm is robust even against our 'imperfect' hands.

Very cool, thanks for the response. Neat project btw.

Thanks!

Speaking of 'neatness', I just pushed an update that lets you generate a visual Result Card of your reading.

So now you can get a nice downloadable souvenir of that Gaussian-distributed hexagram. :D

Functionally it makes no difference whether you split near the middle or not -- a truly random selection would sometimes end up with a pile of one, and that's totally fine. As long as you're not trying to game the system by, say, specifically counting out the sticks to get the outcome you want, it makes no difference. (and if you're doing that, then what's the point?)

Splitting closer to the middle does make it easier to avoid unintentionally counting though. If you make the same splits every time, you'll get the same outcome of course.

Philosophically / spiritually speaking, "don't think about it too much and just split wherever feels right" is the simple answer. Keep in mind the question you want to ask when you make the split and let whatever happens happen. Close your eyes if it helps you focus.

> Functionally it makes no difference whether you split near the middle or not -- a truly random selection would sometimes end up with a pile of one, and that's totally fine.

Yeah I just mean I would be very conscious of splitting with a single stalk in one group and would wonder if that was really a 'fair' selection or something I did intentionally since I know the exact number of the yarrow in one hand. In practice, I can't imagine anyone would make a selection like that, even though in a truly random system it would happen not infrequently.

Having a certain number in one hand is still a couple steps removed from getting a specific outcome, so there isn't anything inherently 'unfair' about it. My point was more that it's the intention that matters. If you make a split because it feels right, with your question in mind, then it's fine if it's totally uneven and/or you're aware of how many there are. Splits like that do happen from time to time, it's all part of it.

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