[EM] Improvement to Ranked Robin method

[Kristofer Munsterhjelm]

On 03.04.2022 06:24, Richard, the VoteFair guy wrote:
> On 4/1/2022 12:04 AM, Colin Champion wrote:
>> Llull,Borda computes Borda scores on the entire field and
>> elects the Llull winner with the highest Borda score.
>>
>> Llull//Borda simulates a Borda-count runoff between the
>> Llull winners. This can be done using totals computed from
>> the original ballots.
>>
>> When I did a big simulation last year ...
>> ... I called Llull,Borda "Llull with a full Borda tiebreak"
>> and Llull//Borda "Llull with a restricted Borda tiebreak" ...
> 
> Thanks, then the current definition of the Ranked Robin method is
> Copeland//Borda -- not Copeland,Borda.
> 
> In contrast, I'm suggesting using pairwise support counts,
> which are described this way:
> 
> On one ballot the pairwise support count is the number of candidates who
> are ranked lower than the candidate getting the support count.  These
> counts are added across all the ballots to yield that candidate's
> pairwise support count.
> 
> A big advantage of this method is that there is no need to teach voters
> about pairwise vote counting beyond the win-lose kind, namely which
> candidate got more votes than the other candidate in the pair.
> 
> In turn, this means there's no need to mention the pairwise matrix,
> which is confusing to many people.
> 
> More importantly, this improved version does not suffer from the ability
> to vote tactically, which is a big weakness of the Borda Count.

Could you give an example without truncation or equal rank, where your
count elects a different candidate than the Borda count restricted to
the same candidates?

If the outcomes are the same then I don't think your count would be any
less (or more) strategically vulnerable than the Borda count.

-km