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    Bottom Two Runoff (Condorcet IRV hybrid)

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    • rob
      rob Banned @Jack Waugh last edited by

      @jack-waugh I'm saying that, if equal ranking is allowed, it doesn't make it a different method. It is just one variation of the same method. Note that the Electowiki page for IRV mentions the possibility of equal ranking, and here is a (very short) discussion of equal rank IRV: https://www.reddit.com/r/EndFPTP/comments/dgzf5k/what_are_the_shortcomings_of_equalrank_irv/

      I'm not speaking of the practical issue of whether Fairvote or RCV IRV Hare enthusiasts will allow it, whether voting machines can deal with it, whether it is allowed under some specific legislation, etc. That's a different issue.

      I imagine the best way to handle equal rankings would be to count fractional votes. (I will need to implement it so I can process cardinal ballots as IRV-Hare and IRV-BTR)

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        Jack Waugh last edited by

        Untested, draft code for tallying RCV-IRV-B2R: tally.mjs

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          Jack Waugh @rob last edited by

          @rob said in Bottom Two Runoff (Condorcet IRV hybrid):

          I will need to implement it so I can process cardinal ballots as IRV-Hare and IRV-BTR

          naive_strict_ranking.mjs is an untested draft for converting affinities (same form as so-called "cardinal" ballots) into ranking ballots. The assumption underlying my design of the code is that equal-ranking is forbidden except for the sludge at the bottom.

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            Jack Waugh last edited by Jack Waugh

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              Jack Waugh last edited by Jack Waugh

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                Jack Waugh last edited by

                For simulations and small elections in particular, it's in my opinion important to understand the corner cases that can arise in Bottom-Two Runoff, and decide how the outcome should be determined. One reason to think this way is to make sure that the tallying algorithm is deterministic. A deterministic algorithm will make all experiments repeatable, that are based on applying the algorithm to a given set of example data.

                I posted an algorithm or two in here, but it or they were wrong.

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                  Jack Waugh last edited by Jack Waugh

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                    Jack Waugh last edited by Jack Waugh

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                      Jack Waugh last edited by

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                        Jack Waugh last edited by

                        I have advanced the code from where it was crashing every time to where it gives wrong answers, so that's progress.

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