User:RobLa/runoff

This is the page where User:RobLa keeps track of various ideas (his ideas and others' ideas) regarding putting all candidates into a playoff bracket, and then seeing how they fare head-to-head. It's arguable that Llull was the first person to think of this, but pairwise voting has been around for a while.

There are many people who are not "good at math" who pay attention to March Madness and/or the Wimbledon championship and/or any number of other single-elimination tournaments. There's often a debate about whether the seeding of the tournaments is fair, It seems to User:RobLa that seeding the tournament such that all members of the Smith set are guaranteed to advance to the final rounds, and that it seems likely that some variation of Copeland's method could be used for seeding.

It would seem as though Ranked Robin is an interesting variant on the idea.

Genuine Instant Runoff
This is a proposal that User:RobLa devised in 2018:


 * 1) Create a playoff bracket with room for all candidates
 * 2) *1a..... using rules similar to the ones the NCAA uses for March Madness:
 * 3) **https://en.wikipedia.org/wiki/March_Madness
 * 4) * 1b. ....or maybe on the ones Wimbledon uses:
 * 5) **https://en.wikipedia.org/wiki/Wimbledon_championship
 * 6) *1c. In short, use a single-elimination tournament:
 * 7) **https://en.wikipedia.org/wiki/Single-elimination_tournament
 * 8) Seed the candidates in the tournament such that all members of the Smith set are guaranteed to advance to the final rounds.  I'm guessing that the Copeland score could be used:
 * 9) *https://en.wikipedia.org/wiki/Copeland_method
 * 10) Calculate the winner of each contest using the standard ways of inferring pairwise matchup results based on ranked/rated ballots

These steps may seem like a lot of theatrical extras (especially in contests where there is a single Condorcet winner) but I think this framework could provide a useful mental model for people whose eyes glaze over when try to describe some of the mathematical vulnerabilities of systems like Instant Runoff.

MAF and MATT
In keeping with the "runoff" name, here's a couple of new voting systems I worked on in late 2018 as possible alternatives to California's jungle primary:


 * Majority approval filter (MAF)
 * Maximum approval top-two (MATT)

2022-08-26

 * updated: 01:47, 27 August 2022 (UTC)

Another reddit discussion ("/r/EndFPTP: Condorcet Bracket (for single-winner elections)") inspired me to update this page.

2022-03-15

 * updated: 02:13, 16 March 2022 (UTC)

There was a discussion on reddit the other day titled "/r/EndFPTP: Alright, new system: Championship Voting". Of course, there's nothing new under the sun. It could be that Condorcet ripped off Llull, but my hunch is that Condorcet just independently invented the same system that Llull created. Regardless, I'm going to keep writing this up (especially because of rumors I've heard about "Ranked Robin").

2021-02-03
I didn't make the proposal to the EM-list. Oh well. Many other things came up in my life. -- RobLa (talk) 22:32, 3 February 2021 (UTC)

2018-12-02

 * Below is a comment from December 2018 -- RobLa (talk) 22:32, 3 February 2021 (UTC)

Comment from 04:46, 2 December 2018‎ : [Below] is a working version of a proposal I'm about to make on the election-methods mailing list.

1.  Create a playoff bracket with room for all candidates, using rules similar to the ones the NCAA uses for March Madness:

< https://en.wikipedia.org/wiki/March_Madness >

....or maybe on the ones Wimbledon uses:

https://en.wikipedia.org/wiki/Wimbledon_championship

In short, use a single-elimination tournament:

https://en.wikipedia.org/wiki/Single-elimination_tournament

2.  Seed the candidates in the tournament such that all members of the Smith set are guaranteed to advance to the final rounds. I'm guessing that the Copeland score could be used:

https://en.wikipedia.org/wiki/Copeland_method

3. Calculate the winner of each contest using the standard ways of inferring pairwise matchup results based on ranked/rated ballots

These steps may seem like a lot of theatrical extras (especially in contests where there is a single Condorcet winner) but I think this framework could provide a useful mental model for people whose eyes glaze over when try to describe some of the mathematical vulnerabilities of systems like Instant Runoff.

(UPDATE: it's possible to see the note above in the version history for this page, and here: https://electowiki.org/w/index.php?title=User:RobLa/runoff&oldid=5182 )