Yeah, I'm not sure where the qualms about monotonicity are coming from. In an IRV the lower-ranked preferences do not count until the higher-ranked preferences have already been eliminated for not reaching majority

https://rangevoting.org/Burlington.html here's a real life election with a Condorcet winner in which IRV elected some other candidate.

The reason there are not more examples like this one is that most governments don't release enough information about ballots in IRV elections.

As soon as I can find some time to work through that, I'll give my thoughts.

But ... is there maybe a truncated explanation of the general dynamic there?

Basically, imagine you have three candidates: A, B, and C, and there are 50 voters, and the votes come in like this:

  100 - A > C > B
  100 - B > C > A
  40 - C > A > B
  10 - C > B > A

After round 1 of IRV, candidates A and B each have 100 votes, C has 50. C gets knocked out, 40 votes move to A, 10 votes move to B. A now has 140 votes, and B has 110, and A is declared the winner.

The problem is that the B > C > A don't get their second choice considered. Why does this matter? Look at it when you put the votes into pairs.

  A vs B: 140 people think A > B.  110 think B > A.
  A vs C: 100 people think A > C.  150 think C > A.
  B vs C: 110 people think B > C.  140 think C > B.

C is actually the more popular candidate, but C LOSES using IRV!

> Edit: As much as everyone's trashing IRV as "horrible" I don't see a simple, worrisome case where it violates monotonicity;

It's terrible because the loser-elimination step that makes non-monotonicity an issue also makes it less straightforward to tabulate, not because non-monotonicity is an issue outside of edge cases.

Yeah I guess I’m just not really invigorated by fears of “difficulty of tabulation” and “bad behavior on edge cases”. Maybe I react differently from the typical voting system enthusiast?

> Yeah I guess I’m just not really invigorated by fears of “difficulty of tabulation” and “bad behavior on edge cases”.

Difficulty in tabulation affects speed of, certainty of, and confidence in results, as well as cost of implementation.

> Maybe I react differently from the typical voting system enthusiast?

Nope, especially on neglecting pragmatics like tabulation; that's practically a hallmark of voting system enthusiasts.

>Difficulty in tabulation affects speed of, certainty of, and confidence in results, as well as cost of implementation.

Which doesn't rise to the level of "that is so bad it must be stopped".

>> Maybe I react differently from the typical voting system enthusiast?

>Nope,

Kind of strange, since the entire reason for my confusion and joining this thread is because of enthusiasts' doom-and-gloom about the quality of the results themselves, and how they worry about the edge cases and I don't.

Are you invigorated by the cost fears? Because they seem like a sliver compared to the cost of Gore vs Bush.

I guess I can't comprehend how someone doesn't view non-montonicity as a fatalflaw in a voting system.

If I can hurt my preferred candidates chances of winning by ranking them higher on my ballot then the voting system is broken.

Non-monotonicity is a problem.

Non-monotonicity solely on a few pathological edge cases where voter preferences are a nigh-intransitive clusterf—- is not a problem.

I think that the Burlington example that has been cited a lot in this thread shows that non monotonicity is a problem for IRV in not just pathological edge cases.

The problem with difficulty to understand isn't a simple logistical fear. It's fear that voters won't understand what their vote means.

I never expressed mystification at comments that expressed that fear, because it actually makes sense.

Also, it's that they won't have a basis for respecting the result when their candidate loses.