I’m not familiar with Approval or Score, so I shall refrain from commenting on them.
There are many different voting methods. It’s been mathematically proven that none are perfect, and all have strengths and weaknesses, but under utilitarian systems like Approval and Score, it is always a good strategy to give your full support to your favorite, and full opposition to your least favorite. It’s the in-between candidates that have incentives for strategic voting. Systems that have this property are said to pass the Favorite Betrayal Criterion.
Systems like STAR Voting and 3–2–1 Voting try to disincentivize both types of strategy by not meeting the FBC perfectly. I think they're probably the best compromise between competing requirements.
The point you made about ranked ballots is quite right.
My point is not about ranked ballots, though. It’s about the instant-runoff tallying method in particular. There are other ranked-choice methods that don’t have this problem.
It’s very frustrating that it’s marketed using the generic phrase “Ranked-Choice Voting”, which confuses people into focusing entirely on the ballot type and not realizing that the flaws are due to the tallying method. :(
It depends on how how many spots a voter is given to fill in.
No, the spoiler effect I talked about in the comment that you’re replying to is not related to how many spots a voter fills in. It happens even when every voter fills out a complete, honest ballot. It’s a flaw in the way votes are tallied to find a winner, due to focusing purely on first-ranked preferences.
But that could be solved by having three spots on the ballot to indicate preferences. Unfortunately, that complication will cause confusion with some voters.
Ideally, a ranked ballot would have as many spots on the ballot as there are candidates. I don’t think that causes any confusion, as long as voters are allowed to leave some spots blank.
Again, that’s not related to IRV’s spoiler effect, though.
I think we need to really re-think democracy to a system with no political parties.
Political parties are just a shortcut to understanding a candidate’s political platform. I don’t think there’s anything wrong with that; I just want to end the two-party system that locks out other alternatives. We should use voting systems that don’t suffer from vote-splitting or spoiler effect, so there can be as many candidates from as many different parties as there are ideologies, without stepping on each other's toes and resulting in unrepresentative outcomes.
IRV/RCV is not good at this, it tends to perpetuate a two-party system, but the other voting systems I mentioned can help a lot.
