The key point which is laboured a couple of times is that some seat results are different than plurality outcomes. But that is a feature of IRV, not a bug.
Had the election been run under plurality rules voters would of voted differently and this fact seems to of escaped the author of this website.
Voters who preferenced greens first, recognising a minor parties zero chance of winning under plurality would of instead cast votes according to two party preferred lineup, who mostly would ideologically align with labour. But under IRV they can vote for anyone they feel more closely represents them but still have meaningful input into a 2PP outcome.
Show me a critique of an IRV outcome where 2PP outcome violates Monotonicity and you'll have a real critique of IRV.
However, in close three-cornered races, tactical voting does sometimes come into play. The recent Wentworth by-election was an example of this: Liberal voters could have assisted their party to win the election by switching their first preference to the Labor candidate, because if the Labor candidate had beaten the eventual winner (Phelps, Independent) into second place, then Phelps' preferences would have been distributed and almost certainly given the win to the Liberal. Of course, this is a risky strategy, because if too many Liberal voters did this then they would have instead engineered a Labor win. And in reality, despite the possibility of tactical voting, the Condorcet winner Phelps won anyway.
An example where the Condorcet winner may not have won is the seat of Rockhampton in the 2017 Queensland State election. The primary votes had Labor in first, independent Margaret Strelow in second, One Nation in third and the LNP in fourth. However preferences from the LNP candidate pushed One Nation into second, which gave Labor the win on Strelow's preferences. It seems likely that Strelow would have beaten any of the other three head-to-head, though. And as previously mentioned, this sort of situation is notable for its rarity.
That doesn't affect the tactical voting possibility there - the possibility arose because the Liberal candidate's chances were greatly affected by which of the other two major contenders made it into the final runoff.
Huh? There isn't a clear-cut way of determining the best voting system, so how were they compare the two? That matters quite a lot.
There are situations where IRV get so complicated it is unpredictable, but living in Australia that does sometimes feel like a feature - if the polity expresses no strong consensus preference, random selection amongst candidates is not a bad idea.
> Approval voting and range voting are ... strictly better
Yeah, totally [0]. Approval voting looks like the one to use just in terms of doing what a voting system does.
Any system that lets neutrals and moderates in occasionally is better than plurality. And plurality is streaks ahead of having no choice at all.
https://rangevoting.org/IrvExec.html
There are many examples of voters in real-world IRV elections _do_ rank their favorite candidates last, to help them win (the same problem plurality voting has, but worse, because there are multiple plurality runoff votes).
Mathematical models also agree – situations in which IRV produces bad results are extremely common. Something like 70% of possible situations where IRV and plurality voting produce different results, the IRV result is worse than the plurality result.
Approval voting and range voting are really the only voting systems I know of that are strictly better than plurality. They have their flaws, but per Arrow's Impossibility Theorem, there aren't any voting systems without flaws.