[Election-Methods] RE : Corrected "strategy in Condorcet" section, Chris

[Chris Benham]

Kevin Venzke wrote:

>Chris,
>
>  
>
>>-------------------------------------------
>>From: Chris Benham[SMTP:CHRISJBENHAM at OPTUSNET.COM.AU]
>>Kevin Venzke wrote:
>>
>>I think a better method that would achieve everything you are  
>>trying to do with your method (technically
>>if not "psychologically") would be this:
>>
>>"1) Voters indicate one Favourite and also Approve as many  
>>candidates as they like.
>>
>>2) Any candidate voted as favourite on 50% or more of the ballots  
>>wins.
>>
>>3) Eliminate any candidate whose max. approval opposition score is  
>>greater than 50%, unless that is all
>>the candidates.  [I'm not sure if that's possible].
>>
>>kv:
>>Nope, that's not possible. You can only get this score if someone else
>>has majority approval and you don't. It's an MD filter really.
>>  
>>
>>4) Of the remaining candidates, the two voted as favourite on the  
>>most ballots go to the second round."
>>
>>This uses a more expressive ballot and mainly confines the split- 
>>vote problem to the "top" of the ballot.
>>So the normal recommended strategy in the 3 viable candidates  
>>scenario would be vote the most preferred
>>of the 3 as favourite, and approve all the candidates you prefer to  
>>the least preferred of  the 3.
>>
>>What do you think of that?
>>
>>kv:
>>I've had this exact thought... I agree that on paper this should be 
>>similar in effect and better.
>>
>>
>>Kevin,
>>Thinking about this a bit more, why not expand this into a fully-fledged
>>3-slot method?
>>
>>"Middle-slot votes count only as approval for calculating max. approval
>>opposition scores.
>>Candidates with a Max. AO score greater than 50% of the valid ballots are
>>eliminated.
>>Elect the remaining candidate with most top-slot votes."
>>
>>I think that would be like a CDTT method. Wouldn't we then have a method
>>that meets
>>Minimal Defense, a variety of Later-no-Harm (middle-rating candidates
>>can't harm the voter's top-rated
>>candidates),FBC and  mono-raise; but fails Plurality,  3-slot Majority
>>for Solid Coalitions, and Irrelevant Ballots,
>>and has a sort of random-fill incentive?
>>
>>What do you think of that? It seems so Venzke-like, have you ever
>>proposed it? 
>>    
>>
>
>I don't know that I have proposed this method, but I have implemented
>this method in my triangle plotter under the name "MD,FPP." I doubt
>this method is as good as CDTT,FPP... Here are a couple of scenarios
>where they differ:
>
>39 A>C, 41 B>C, 20 C>B : MD,FPP picks B, CDTT,FPP picks C
>
>In MD,FPP the A voters' compromise vote is less useful; also the C voters
>would've gotten a C win if they had truncated.
>
>  
>

Kevin,
Yes, so my LNHarm claim was wrong.  I had to refresh my memory on 
exactly what the CDTT is.

http://wiki.electorama.com/wiki/CDTT

Do you think  CDTT,FPP(whole)  (or  CDTT,MMPO,FPP(whole) ?) is a good 
3-slot method?

Chris Benham

>49 A, 24 B>A, 27 C>B : MD,FPP picks A, CDTT,FPP picks B
>
>Similar story here.
>
>I would guess that MD,FPP is less vulnerable to offensive strategy...
>
>Kevin Venzke
>
>
>      _____________________________________________________________________________ 
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>  
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