[EM] Coombs method and typical RCV hybrid, River

[robert bristow-johnson]

> On 01/23/2022 12:46 AM Daniel Carrera <dcarrera at gmail.com> wrote:
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> On Sat, Jan 22, 2022 at 11:35 PM Forest Simmons <forest.simmons21 at gmail.com> wrote:
> > Mike Ossipoff once reported explaining Schulze to the complete satisfaction of his non-technical girlfriend, by using an equivalent, but more intuitive, "beatpath" formulation of Schulze:
> > 
> > A beatpath is a chain of defeats leading from one candidate to another. A chain is no stronger than its weakest link.
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> > We say that X strongly beats Y when X has a stronger beatpath to Y than Y's strongest beatpath to X.
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> > Elect the candidate that strongly beats every other candidate.
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> [friendly_sarcasm] Yeah, the TV ad just writes itself! [/friendly_sarcasm]
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That's not so bad.  I consider that the most concise explanation of Schulze with normal language that I have read.  Must include that the strength of each link in the chain is either the winning margin or just the winning votes in that pair of candidates.

Not yet suitable for legislation.  But is a really good way of expressing the algorithm.

> More seriously though, phrasing it like that does help. I still think it's quite difficult. I'm not confident that I will remember this explanation in 8 months.

I think I will.  I had already understood Schulze (with margins or with winning votes) but hadn't had as concise an explanation as that.  Sometimes it needs coming up with the best term for a single concept.  In this case "strongly beats".

For Bottom-Two_Runoff, I came up with the term "lesser voter support" to differentiate from having fewer votes.

I now have written some crude, untested, C code for Ranked Pairs and I just really don't see how to turn it into language plausibly suitable for legislation.

> Also, it is one thing to explain the algorithm and another to convince me that the algorithm makes sense. That's another place where I think RP has an advantage. If an overwhelming majority is adamant that A > B, then you gotta respect that; it's just democracy. Whereas if people generally say C > A but they are a little "meh" about it, then maybe that's the one to throw away.

Yup.  I think that's what Nic was thinking.

> Also, I didn't have to look up RP to remember that, and I'm confident I'll remember it 8 months from now. I think it's just the principle of basic fairness, whereas Schulze feels like it's trying to be too clever and I don't intuitively trust what would come out of that.
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well that Ossipoff interpretation helped me a lot.  It very nearly spells out the fundamental defining principle that is unique to Schulze.

Markus, are you listening in?  What do you think of the Mike Ossipoff expression of the Schulze method?  Maybe you had already expressed it as such and I just missed it.

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r b-j . _ . _ . _ . _ rbj at audioimagination.com

"Imagination is more important than knowledge."

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