[EM] Copeland//Plurality --- can it beat IRV?

[robert bristow-johnson]

> On 01/23/2022 3:23 AM Forest Simmons <forest.simmons21 at gmail.com> wrote:
> 
> 
> Here's a very simple, seamlessly Condorcet compliant method with an IRV flavor... but instead of eliminating the candidate with the fewest first place votes at each step, it eliminates the candidate with the poorest showing in any "matchup" among the remaining candidates:
> 
> While there remain two or more candidates, eliminate the one with the fewest votes in any matchup among those remaining candidates.

But isn't that sorta just a stronger way of doing Bottom Two Runoff?

Both methods are eliminating one candidate at a time and both insure that it's not the Condorcet winner that is eliminated.

As long as the candidate count is being reduced and the CW cannot be eliminated, you're pretty much assured of ending up with the CW as the last candidate standing.

> Then elect the sole survivor.
> 
> If at any stage two or more candidates tie for fewest votes, look at second fewest, etc until the tie is broken. Beyond that start comparing max opposing votes, etc. This tie breaker hierarchy is easy to justify, easy to execute, and as decisive as all get out!
> 

ya know, that's actually true.  I wonder if it's better to use margins, instead of fewest votes.  So you eliminate the candidate that is defeated with the largest margin in each round.

> This method cannot eliminate the CW because the candidate with the fewest votes will have fewer votes than the CW in their matchup, and perhaps even fewer in some other matchup.
> 
> It is so computationally simple that a small child can do it manually, given a copy of the pairwise matrix:
> 

But it's more laborious than BTR.  BTR has to do only one "matchup" per elimination round.

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

"Imagination is more important than knowledge."

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