This is an example that Condorcet handles reasonably because there are no
cycles. B and C have a united coalition - one of them is guaranteed to win
by any good method.
The question here in judging between using Runoffs or Condorcet is whether
you want A supporter's second rank preference to decide a winner between B
and C. Since B and C have a mutually united coalition we might imagine they
were in the same party and a primary could have chosen between them which
should run against A. Well, I mean this shows why IRV can replace primaries
while Condorcet can not.
My original email said use Condorcet if there is a candidate that beats all
others in pairwise elections and otherwise use plurality among the top set
of mutually pair-defeatable candidates.
Tom
From: "Buddha Buck" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Tuesday, April 10, 2001 3:30 PM
Subject: Re: Mixed Condorcet-Plurality
[snipped]
...
> Here's an example where Plurality, Condorcet, and IRV all yield different
> results!
>
> 45 ABC
> 35 CBA
> 20 BCA
>
> Plurality: A wins
> IRV: B is eliminated, and 20 votes transfer to C, C wins
> Condorcet: B defeats A 55:45, B defeats C 65:35, B wins
