[EM] MinMax Losing Votes (equal-ranking whole) Margins

[robert bristow-johnson]

On 6/11/14 1:36 PM, C.Benham wrote:
>
> On 25 April 2014  I first suggested the  'MinMax Losing Votes 
> (equal-ranking whole) Margins' Condorcet method:
>
>> *Voters rank from the top however many candidates they wish Truncation
>> and equal-ranking is allowed.
>>
>> A pairwise matrix is created, giving normal gross scores except that
>> ballots that explicitly equal rank (not truncate) any two
>> candidates X and Y give a whole vote to each in that pairwise contest.
>>
>> Using this information, give each alternative a score that equals the
>> smallest number of votes it received in a pairwise loss.
>>
>> Henceforth we are only concerned with the direction of the pairwise
>> defeats and these individual candidate scores.
>>
>> Use the Schulze algorithm, weighing each pairwise "defeat" by the
>> absolute margin of difference between the two candidates'
>> scores.  (Or use Ranked Pairs or River in the same way if you prefer).
>>
>> Or use the candidate scores for the Margins Sort algorithm.*
>
> I've given some more thought on how to handle some types of ties.
>
> *If we are using the  Score Margins Sort  algorithm and there is an 
> exact tie in the
> sizes of the margins between pairs of pairwise out-of-order adjacent 
> candidates,
> make the flip that results in the lowest-ordered candidate being 
> further lowered.
>
> If we are using a method that ranks pairwise defeats, and more than 
> one of the pairwise
> results has the exact same MMLV(erw) score margin, then rank them from 
> strongest to
> weakest according to the loser's score, i.e. among defeats by the same 
> margin those where
> the loser has a lower score are we deem weaker than those where the 
> loser has a higher score.*
>

Chris, could you do me a fav?  could you put this into a sorta flow 
graph or pseudocode step-by-step?  i can't quite grok how it's different 
from the existing Schulze or Ranked Pairs or whatever based on Margins.  
(or is it *not* based on Margins?)

sorry i'm sorta clueless.

-- 

r b-j                  rbj at audioimagination.com

"Imagination is more important than knowledge."