[EM] Winning votes criteria against margins criteria.

[Stephane Rouillon]

Hi bunch,

from what I concluded:

1) Winning votes is resistant to truncature when it comes to protect a
strong Condorcet winner:
it means a group of electors cannot get their favorite candidate elected
instead of the Condorcet winner
if this Condorcet winner has a 50%+1 majority against each other
candidate by simply removing the end
of their sincere preferences from their ordered ballot.

2) However, winning votes is not resistant to truncature when it comes
to protect a weak Condorcet winner:
it means a group of electors could get their favorite candidate elected
instead of the Condorcet winner
if this Condorcet winner has less than 50%+1 majority against some other
candidate by simply removing the end
of their sincere preferences from their ordered ballot.

Proof of the two previous statements can be found in the electorama
archives. (1) From Mike Ossipoff
and (2) with some counter-examples I provided.

In addition, I suspect:

3) Margin is resistant to truncature when it comes to protect a stronger
Condorcet winner:
it means a group of electors cannot get their favorite candidate elected
instead of the Condorcet winner
if this Condorcet winner has a 66%+1 majority against each other
candidate by simply removing the end
of their sincere preferences from their ordered ballot.

4) Winning vote could however be more sensitive to unsincere order
reversals (From M. Blake site) than margin
(I have no clue for relative margin).

S. Rouillon