If you consider the example
10% FarRight>Right>Centrist>Left>FarLeft
10% Right>FarRight>Centrist>Left>FarLeft
15% Right>Centrist>FarRight>Left>FarLeft
16% Centrist>Right>Left>FarRight>FarLeft
15% Centrist>Left>Right>FarLeft>FarRight
13% Left>Centrist>FarLeft>Right>FarRight
11% Left>FarLeft>Centrist>Right>FarRight
10% FarLeft>Left>Centrist>Right>FarRight
Considering the electorate as 3 factions- Right 35%, Centre 31%, Left 34% IRV is doing exactly what I want it to do - preventing Centrist dominance.
Your general argument is that a centrist can win a Condorcet election even if he has lukewarm support, which is a reasonable point, although I would argue it. But here, you are arguing that defeating the centrist is a virtue unto itself. That's just completely ridiculous.
You seem to have fallen victim to your own rhetoric. You seem so sure that every difference between Condorcet and IRV can be explained away by the "weak center" argument that you've ignored what the voters have said here - that centrist is by any reasonable measure the strongest candidate. Why all of a sudden are the first place preferences are no longer especially meaningful?
Just to review, Centrist has the most first place votes, the most second place votes, and the most third place votes, and is the only candidate not found in fourth or fifth place on any ballot. How can you possibly argue that centrist isn't the people's choice?
Under Condorcet the only way the Right or Left factions could win is if they obtained 50%+ of the first preference vote.
I would argue that this amounts to enforcement of majority rule.
I am prepared to live with the possibility of your example if it prevents Right 42%, Centre 17%, Left 41% with the Centre winning.
So essentially, you are saying that defeating the weak centrist is such a high priority for you that you are willing to take down the strong centrist as well. This begs the question, why the bias against compromise parties? I don't see how the defeat of this strong centrist is any worse than the victory of your weak centrist. And the latter scenario has the advantage of the Condorcet argument - that is, that the winner would win any two-candidate race.
-Adam
