[EM] Condorcet Ties

[Blake Cretney]

On Mon, 19 Feb 2001 13:52:14 -0500
"Moe St. EverGreen" <evergreen at lovemail.com> wrote:

> What are the most acceptable forms of tie breaking
> other than random, that might be used before random
> in the case of Condorcet Voting.
> 
> I mean actual ties in voting preferences
> and not merely failure to have a Condorcet approved 
> candidate.

If you don't want to use random, I think it's a good idea designate
one person as the tie breaker.  You can set up some rather complicated
rules to break ties based on the ballots, but these generally don't
make much sense, and don't give any result in the most common
situations (like a simple two-way tie).

> ps.
> Also, I notice that the EM webpage does not list
> Condorcet as a voting system, but rather lists Minmax as
> the name of the system.. but with a different type of counting
> (Minmax as described there goes for a minimum score 
> rather than for a maximum score as described at 
> http://electionmethods.org/)

That's my unofficial Election-Methods Resource site:
http://www.fortunecity.com/meltingpot/harrow/124

I recommend that anyone who wants to know what Condorcet actually
recommended should read Condorcet.  He is of course most famous for
recommending that the pairwise unbeaten candidate should win.  This is
called the Condorcet winner, and some people refer to Condorcet's
method as just this procedure.

Of course this method is prone to ties.  So, some people on this list
chose a convenient Condorcet completion method, which they called
Condorcet (EM) or Condorcet.  That electionmethods.org site calls it
Plain Condorcet.  I call this Condorcet (EM) on my site.

In academic journals, choosing the least defeated seems to be called
Minmax.  I use this name for the method where the strength of a defeat
is decided by the margin.  You'll notice that Condorcet (EM) decides
strength of a defeat by votes on the winning side.  Other than that,
it's the same method.

The procedure given for Plain Condorcet on electionmethods.org is
equivalent to what I call Condorcet (EM), even though this may not be
obvious.

> Is there another name for Condorcet voting,
> and is Condorcet voting currently considered the best option
> for a single winner race?

That's a little like asking which religion is considered the best. 
The short answer is, it depends who you ask (as well as what you mean
by "Condorcet").  

My preference is for Ranked Pairs, which is a Condorcet completion
method detailed at:
http://www.fortunecity.com/meltingpot/harrow/124

There's even a (low activity) list set up for discussing it.

---
Blake Cretney