FpA-fpC

fpA-fpC (for first preference A minus first preference C) is a three-candidate Condorcet method based on first preference Copeland. It was first proposed by Kristofer Munsterhjelm in 2016. Its election cases are:

• If there's a Condorcet winner, then that candidate wins.
• If the Smith set is size two, then the winner is according to majority rule.
• If the Smith set is size three, then for each candidate, assume without loss of generality that the candidate is A in an A>B>C>A cycle. A's score is A's first preferences minus C's first preferences. The candidate with the highest score wins.

This method shares the strategy resistance of Smith-IRV hybrids, such as chicken dilemma compliance and dominant mutual third burial resistance; yet, unlike them, is monotone. It is open (not obvious) how to extend the method to more than three candidates in a way that retains both monotonicity and strategy resistance.

Chicken dilemma

see also: Chicken dilemma

Any generalization will preserve its chicken dilemma compliance, as that criterion is only defined on three-candidate elections. However, this is not true of dominant mutual third burial resistance.

It produces similar results to electing the winner according to Carey's Improved First Past the Post method if there is a Condorcet cycle, and electing the Condorcet winner otherwise.

Historical emails

This is a list of emails to the EM-list, originally compiled by User:Kristomun in a comment on the "Talk:" page for this article, but possibly augmented by others after February 2022:

• "Strategy-resistant monotone methods" 2016-02-07 (User:Kristomun)
• "Re: MJ -- The easiest method to 'tolerate'" 2016-09-22 (User:Kristomun)
• "Resolvable weighted positional systems all fail independence of clones" 2017-12-03 (User:Kristomun)
• "Fwd: What are some simple methods that accomplish the following conditions?" 2019-06-01 (Forest Simmons)
• "Re: Improved Copeland" 2019-06-07 (User:Kristomun, also Forest Simmons)
• "Unmanipulable majority and Condorcet" 2020-01-03 (User:Kristomun, also Forest Simmons)
• "Minimally manipulable methods: preliminary results" 2020-11-02 (User:Kristomun; first post about the MIP minimally manipulable method search)
• "Re: A Metric for Issue/Candidate Space" 2020-12-23 (Kevin Venzke)
• "Re: Best Ranked Preference Deterministic Method?" 2020-12-24 (User:Kristomun, KV, FS)
• "Re: extending fpA-fpC" 2020-12-26 (Kevin Venzke)
• "Re: Agenda Based Banks" 2021-08-04 (Forest Simmons)
• "Re: Defeat Strength Demystified" 2021-09-17 (Forest Simmons)
• "Re: 'Independence of cycles' and a possible new method" 2021-12-12 (User:Kristomun, Toby Pereira, Colin Champion, Forest Simmons)
• "Re: Quick and Clean Burial Resistant Smith, compromise" 2022-01-09 (User:Kristomun, Kevin Venzke, Daniel Carrera, Forest Simmons)