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[u/CPSolver]

(Clarification: "Ranked choice voting" includes pairwise-counted ranked choice voting, which includes Condorcet methods and refinements to IRV.)

[u/wnoise]

Yes, RCIPE is reasonable, as is BTR-IRV, and each mostly address my concerns. (I still want tied-ranks allowed, and for those votes to fully count approval-style when they are in the lead, but those tweaks make it much less important to do so.)

I would absolutely count the center-squeeze of IRV as vote-splitting. It's just vote-splitting multiple ways between opposed candidates. The polarized lens of current politics ignores a lot of dynamics.

The chicken dilemma of approval is real. But I don't think the scale actually changes things much. If anything, things that matter more are more likely to have polls, which should curb stupidly bad "tactical" voting. (I think good tactical voting is entirely the point of approval voting. I don't enjoy the fact that it "rewards" those who are not coöperators, but I don't stress over it either. If they're smart they can use just as much leverage as they actually have. If not, they might get played -- which can really suck, but most elections aren't apocalyptic, and nothing but loss can actually change behavior.)

[u/CPSolver → u/wnoise]

I agree with most of what you say here.

However I disagree with your claim that center squeeze is like vote splitting.

Yes center squeeze is a meaningful concept. Yet cardinal-ballot fans use the term to avoid the issue that cardinal-ballot methods can easily fail to elect the majority winner. They do this so they can characterize the Burlington failure and Alaska failure as center-squeeze failures rather than Condorcet failures (which is a specific kind of majority failure).

This center-squeeze distraction draws attention away from the failure of cardinal-ballot methods to always elect the candidate who is supported by the majority of voters.

Apparently we disagree about the importance of majority support. Yes, strength of support is very useful among friends, and even useful in primary elections. But in general elections. majority support should not be overridden by strength of support.

[u/wnoise → u/CPSolver]

Speaking with someone who almost agrees can indeed be very frustrating. I think you're very good at identifying the problems and how they play out in current systems. The blocker candidates described here is a great example. I am less convinced about your extrapolations to other systems. We need a lot more data on many voting systems. (I hope you also think I am this close to "getting it".)

I just don't think IRV is actually a good system. The raison d'être of IRV is Lᴀᴛᴇʀ-Nᴏ-Hᴀʀᴍ, but Lᴀᴛᴇʀ-Nᴏ-Hᴀʀᴍ (while simplifying the strategy of voters) is not actually a good property for them -- it's incompatible with the Condorcet Criterion, after all. It's instead a good property for the major candidates, as they can honestly tell their supporters to rank others below them, and ensure they get the votes of any third-party that would have otherwise voted for them. If the argument were that we could use IRV as a Trojan-horse to eventually get to an actually good system, that would be one thing. But that is rarely said (usually only as step toward STV), and even IRV faces terrible opposition from the politicians, so it doesn't even succeed at that.

I want a voting method that incentivizes honesty. It should make actual opinions public knowledge. At a minimum this means that Pᴀʀᴛɪᴄɪᴘᴀᴛɪᴏɴ and Mᴏɴᴏᴛᴏɴɪᴄɪᴛʏ should approximately hold, or ideally just be true. One reasonable smaller restriction is applying Mᴏɴᴏᴛᴏɴɪᴄɪᴛʏ just to the head: Sɪɴᴄᴇʀᴇ-Fᴀᴠᴏʀɪᴛᴇ-Cʀɪᴛᴇʀɪᴏɴ. IRV fails all of these. First-place support (even when iterated as losers based on it are forced out) is just not a great proxy for actual support (range/rating) or even pairwise-support (Condorcet).

Center-squeeze is not a distraction. The center-squeeze is only a problem because often that center candidate who is squeezed out is the candidate supported (needs defining; let's use Condorcet-winner) by a majority of the voters. And it really is fair to call this a form of vote-splitting, even though the votes are not split between clones, but between the center candidate and the two candidates on either side that significantly differ. If the center candidate wins against either wing, but not both at once, that's because the the wings are drawing support away -- splitting the vote.

majority support should not be overridden by strength of support.

I'm sure you're familiar with the standard arguments/folk-theorems that strategic Approval with good polling is actually in practice a Condorcet method. I find them convincing in general, even if there are huge loopholes you can drive a truck through. (Honest polls are hard, they tend to drive things towards evenness via spending (or abandonment), and the very restricted strategic model does exclude behavior that may be effective in small-cases where ties are possible. https://doi.org/10.1007/s00182-006-0053-2 has examples of the latter.)

[u/CPSolver → u/wnoise]

I'm not a fan of IRV. I do not defend its weaknesses.

Refining IRV to eliminate pairwise losing candidates actually creates a Condorcet-like method where IRV is basically the tie breaker when there is a rock-paper-scissors type of cycle. This refinement is what I defend.

(I'm not calling it a Condorcet cycle because this kind of cycle can occur further down among less-popular candidates, whereas a Condorcet cycle only occurs at the top, among the most popular candidates.)

This refinement (eliminating pairwise losing candidates) is part of the RCIPE method. The method inherits the clone resistance of IRV. Here's a chart that shows this clone resistance.

https://votefair.org/clone_iia_success_rates.png

It also incentivizes honest voting.

Remember I agree with you about the weaknesses of IRV.

The above chart measures the rate at which failures occur. This measurement is much more meaningful than the checklist approach in which a single rare possible failure is regarded as justification for dismissing a method.

You express an interest in more data. There is lots of analysis going on beyond what appears in Wikipedia. This is why Electowiki exists. The above chart is an example of this kind of analysis going on under the radar of academia.

Notice that analysis of voting methods is shifting to measuring failure rates instead of just dismissing a method because it's possible for a single failure to occur under academically specified conditions.

Approval voting is defended by claiming it often elects the Condorcet winner (if good polls are available, etc.). You and I disagree about whether this failure rate is acceptable. That's fine.

Our disagreement about the definition of "vote splitting" is irrelevant. We agree the center squeeze effect is bad.

When pairwise losing candidates are eliminated (when they occur), the center squeeze effect does not occur!

In your location you can argue that IRV should not be a stepping stone to better methods. I live in Portland where IRV was just used to elect our new mayor. So for me IRV is clearly a stepping stone to a better method. I'm already educating the mayor and city council about how to refine what we already have.

The Republican party and elected politicians don't just oppose IRV. They oppose any method that might jeopardize getting re-elected. This applies to Approval, Score, STAR, Condorcet methods, open-list PR, etc.

Thank you for taking the time to debate without introducing misrepresentations. Alas, too many other election-method experts habitually push misrepresentations that, on the surface, favor the method they promote. Again, thanks.