[Election-Methods] Challenge: Elect the compromise when there're only 2 factions

[Brian Olson]

On Aug 22, 2007, at 2:55 AM, Jobst Heitzig wrote:

> A common situation: 2 factions & 1 good compromise.
>
> The goal: Make sure the compromise wins.
>
> The problem: One of the 2 factions has a majority.
>
> A concrete example: true ratings are
>    55 voters: A 100, C 80, B 0
>    45 voters: B 100, C 80, A 0
>
> THE CHALLENGE: FIND A METHOD THAT WILL ELECT THE COMPROMISE (C)!
>
> The fine-print: voters are selfish and will vote strategically...
>
> Good luck & have fun :-)

With the raw true ratings voted, IRNR, Raw rating summation, and  
approval get the right answer:
http://betterpolls.com/et?vrr=-r&if=-d&cand=3&seats=1&data=*55+100% 
2C0%2C80%0D%0A*45+0%2C100%2C80%0D%0A

But to me the end of the strategy discussion is that the A faction  
could simply bullet vote and no system can recover from a simple  
majority of votes {A=100,B=0,C=0}.
http://betterpolls.com/et?vrr=-r&if=-d&cand=3&seats=1&data=*55+100% 
2C0%2C1%0D%0A*45+0%2C100%2C80%0D%0A