thanks, Chris. i will ponder this. i understand RP and (i think) Schulze, at least how the mechanisms go, but i'll admit i haven't been as invested in *how* to resolve cycles or *which* Condorcet method is best as much as i am invested in (some) Condorcet vs. IRV vs. FPP or two-round runoff. the reason is that i am skeptical of the likelihood of a real election with thousands of voters going into a cycle.

considering both the objective advantages of Schulze and the simplicity of Ranked Pairs, i think that if Condorcet would ever be sold to the general population as a method to decide elections for government, i would suggest Ranked Pairs. but maybe it should be IRV (if a cycle) or something wild-assed. whatever will be needed politically to get people to buy into Condorcet.

maybe it is, but i don't think that is the same mistake as, when the Ranked Ballot is introduced to folks in Vermont or Minnesota or San Francisco or North Carolina, attaching that ranked ballot to the IRV method of tabulation. that was a mistake and it doesn't serve as a stepping stone to better elections with Condorcet (because of entrenchment of IRV supporters and, i believe, a near certainty of IRV displaying anomalies that turn everyone off of IRV and, by association, the Ranked Ballot).

so, keeping RP, Schulze in mind for later, what would be a "good" scheme for resolving cycles by use of elimination of candidates? what would be a "good" (that is resistant to more anomalies) and simple method to identify the "weakest candidate" (in the Smith set) to eliminate and run the beats-all tabulation again? i'm not saying elimination is a good way to do it, but it might be easier to sell to neanderthal voters.

r b-j


On Mar 9, 2010, at 11:45 PM, C.Benham wrote:


Robert Bristow-Johnson wrote (5 March 2010):

i like Ranked Pairs best, too. and if the Smith Set are three candidates, it and Schulze pick the same winner.

> Bringing Plurality in would be a distraction, since we have no need
> to go near this method and risk a worse answer.

it's a "worse answer" in a weird circumstance where an argument could be made that any in the Smith set have some reasonable claim or legitimacy to be elected. why not the guy with the most votes?

Interpreting "most votes" as 'top-ranked on the greatest number of ballots', the answer is that the resulting method
fails the Clone-Winner and  Minimal Defense criteria.

49: A
24: B
27: C>B

A>C 49-27,  C>B 27-24,  B>A 51-49

More than half the voters have ranked B above A and A no higher than equal bottom, and yet Smith,FPP elects A.

The Ranked Pairs and River and Smith//MinMax and Schulze algorithms, using Margins as the measure of defeat strength (referred to collectively as "Margins") and IRV also elect A.

Say we replace A with a set of clones,  A1 and A2.

26: A1>A2
23: A2>A1
24: B
27: C>B

(A2 > C > B > A1 > A2)

Now Smith,FPP elects C violating Clone-Winner. Those other methods I mentioned meet Clone-Winner and so
elect one of the clones (A1).

The number of people (ballots) that voted for (ranked above equal- bottom) the clones and not C exceeds the number that voted for C, and yet C wins violating my suggested "Strong Minimal Defense" criterion.

Chris Benham


http://wiki.electorama.com/wiki/Minimal_Defense_criterion

http://nodesiege.tripod.com/elections/#critmd

http://nodesiege.tripod.com/elections/#critclone

Douglas Woodall splits Clone Independence into "Clone-Winner" and "Clone-Loser". Clone-Winner says that if winning candidate X is replaced by a set of clones than the winner must come from that set. Clone-Loser says that the winner shouldn't change if one (or more) losers are replaced by a set (or sets) of clones.








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