On Fri, Jul 9, 2021 at 4:27 PM Susan Simmons suzerainsimmons@outlook.com
wrote:

It took me some effort to understand the Teams method, but maybe I'm not a
good test. I'm only a little smarter than your average koala ;-)  But let
me offer a different way to write the Teams / River method that might be a
little easier to follow. Among other things, I removed the sports analogy,
moved some of the core concepts higher up, and inserted some redundancy.
Let me know what you think:

Overview... the count is based on the pairwise support matrix.

The winner is elected via a series of rounds in which candidates are merged
into groups, where each group has a unique head. The first round begins
with every candidate being the sole member of a one-member group. Each
round consists of two steps:

1. Identify two groups to merge. Find the group “A” for which the head of
   the group has the greatest pairwise loss against any member of another
   group.

2. Group “A” is merged into the group of the pairwise winner from step (1)
   and the previous head of group “A” is no longer the head of any group.

The rounds end when all candidates have been merged into one group. The
head of this one group is elected.

Cheers,
Daniel

I am neither a lawyer nor a legislator, but I have once "written" legislation that had been adopted into law (by drawing a map) and have reviewed a bunch of RCV legislations.

To get a method adopted into law, you will need to break it down into a deterministic procedure with explicit steps involving well-defined objects: like Candidates, Ballots, Ranking levels (higher or lower), and Counting ballots based on determining some well-defined Conditions.

Candidates will be assigned Status based on the Counting and Conditions spelled out in the definitions.  Off-hand, the status is 1. Elected, 2. Potentially elected (or "Continuing"), and 3. Defeated (or eliminated).

STV has an object called a Single Transferable Vote.  I call that object a "Vote token" but I didn't need the word "token" in the legal language.

In BTR-STV I did have to create a candidate status that I called "Greater Voter Support" and "Lesser Voter Support".

So you need to define which team gets absorbed with which other team.  I cannot be an implicit definition.  And you have to define what being "absorbed" is.  Perhaps "set union" or "combined" might be a better word.

By "pairwise support matrix" do you mean that N by N matrix used to determine the Condorcet candidate?  And how is "strongest pairwise victory" is defined?

--

r b-j . _ . _ . _ . _ rbj@audioimagination.com

"Imagination is more important than knowledge."

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i may have posted this before.  here is the IRV language i used as a template to start with:

All elections of [office] shall be by ballot, using a system of ranked-choice voting without a separate runoff election. The presiding election officer shall implement a ranked-choice voting protocol according to these guidelines:
(1) The ballot shall give voters the option of ranking candidates in order of preference. Lower ordinal preference shall be considered higher rank and the candidate marked as first preference is considered ranked highest. Equal ranking of candidates shall not be allowed. Any candidate not marked with a preference shall be considered as ranked lower than every candidate marked with a preference.
(2) If a candidate receives a majority (over 50 percent of all ballots) of first preferences, that candidate is elected.
(3) If no candidate receives a majority of first preferences, an instant runoff retabulation shall be performed by the presiding election officer. The instant runoff retabulation shall be conducted in sequential rounds. A "continuing candidate" is defined as a candidate that has not been defeated in any previous round. Initially, no candidate is defeated and all candidates begin as continuing candidates.
(4) In each round, every ballot shall count as a single vote for whichever continuing candidate the voter has ranked highest. The candidate with fewest votes is defeated in the current round.
(5) The aforementioned instant runoff retabulation, eliminating one candidate each round, shall be repeated until only two candidates remain. The remaining candidate then receiving the greatest number of votes is elected.
(6) The [governing jurisdiction] may adopt additional regulations consistent with this subsection to implement these standards.

here is how i modified it for BTR-STV:

All elections of [office] shall be by ballot, using a system of ranked-choice voting without a separate runoff election. The presiding election officer shall implement a ranked-choice voting protocol according to these guidelines:
(1) The ballot shall give voters the option of ranking candidates in order of preference. Lower ordinal preference shall be considered higher rank and the candidate marked as first preference is considered ranked highest. Equal ranking of candidates shall not be allowed. Any candidate not marked with a preference shall be considered as ranked lower than every candidate marked with a preference.
(2) If a candidate receives a majority (over 50 percent of all ballots) of first preferences, that candidate is elected.
(3) If no candidate receives a majority of first preferences, an instant runoff retabulation shall be performed by the presiding election officer. The instant runoff retabulation shall be conducted in sequential rounds. A "continuing candidate" is defined as a candidate that has not been defeated in any previous round. Initially, no candidate is defeated and all candidates begin as continuing candidates.
(4) In each round, every ballot shall count as a single vote for whichever continuing candidate the voter has ranked highest. The two candidates with the fewest votes in a round, herein denoted as "A" and "B", shall contend in a runoff in which the candidate, A or B, with lesser voter support shall be defeated in the current round. If the number of ballots ranking A higher than B exceeds the number of ballots ranking B higher than A, then B has lesser voter support, B is defeated, and A continues to the following round. Likewise, if the number of ballots ranking B higher than A exceeds the number of ballots ranking A higher than B, then A has lesser voter support, A is defeated, and B continues to the following round. In the case that the aforementioned measures of voter support of A and B are tied, then the candidate with fewest votes is defeated in the current round.
(5) The aforementioned instant runoff retabulation, eliminating one candidate each round, shall be repeated until only two candidates remain. The remaining candidate then receiving the greatest number of votes is elected.
(6) The [governing jurisdiction] may adopt additional regulations consistent with this subsection to implement these standards.

and, when i was having a discussion with Eric Maskin, we wanted to compare language to what he called "ordinary Condorcet", it's just a speculative guess by me (but  the problem is there is no resolution to a cycle):

All elections of [office] shall be by ballot, using a system of ranked-choice voting without a separate runoff election. The presiding election officer shall implement a ranked-choice voting protocol according to these guidelines:
(1) The ballot shall give voters the option of ranking candidates in order of preference. Lower ordinal preference shall be considered higher rank and the candidate marked as first preference is considered ranked highest. Equal ranking of candidates shall be allowed. Any candidate not marked with a preference shall be considered as ranked lower than every candidate marked with a preference.
(2) If a candidate receives a majority (over 50 percent of all ballots) of first preferences, that candidate is elected.
(3) If no candidate receives a majority of first preferences, a Condorcet-compliant retabulation shall be performed by the presiding election officer.  The candidate who is the Condorcet winner is elected, if the rankings on all of the ballots indicate that this one candidate defeats, by a simple majority of voter preferences, all other candidates when compared in turn with each other individual candidate.  A selected candidate defeats another candidate by a simple majority when the number of ballots ranking the selected candidate higher than the other candidate exceeds the number of ballots marked to the contrary.
(4) The [governing jurisdiction] may adopt additional regulations consistent with this subsection to implement these standards.

I'm just thinking that the language may have to  look something like that,

--

r b-j . _ . _ . _ . _ rbj@audioimagination.com

"Imagination is more important than knowledge."

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Susan,

On Fri, Jul 9, 2021 at 8:56 PM Susan Simmons suzerainsimmons@outlook.com
wrote:

I think I found a slightly simpler formulation of River. It's based on your
"Teams" algorithm but I think strictly speaking we can do without an
explicit mention of teams or groups:

1. First, designate every candidate as a Continuing candidate.
2. On each round, the Continuing candidate with the greatest pairwise
   defeat against any other candidate becomes a Defeated candidate.
3. The rounds continue until only one Continuing candidate remains, who is
   then Elected.

You can see that I'm following RB-J's guidance of using explicit labels for
well-defined objects. Can you confirm that what I wrote above will produce
the same winner as River? If so, then here is my attempt to write the above
method into legalese similar to the examples provided by RB-J:

All elections of mayor, city councilors and school commissioners shall be
by ballot, using a system of ranked choice voting without a separate runoff
election. The chief administrative officer shall implement a ranked choice
voting protocol according to these guidelines:
(1) The ballot shall give voters the option of ranking candidates in order
of preference.
(2) If a candidate receives a majority (over 50 percent) of first
preferences, that candidate is elected.
(3) If no candidate receives a majority of first preferences, the presiding
officer shall re-tabulate the ballots in rounds according to the following
rules:
(3a) A candidate “A” is said to lose against candidate “B” if more ballots
rank candidate “B” above “A” than rank “A” above “B”. The difference
between the number of ballots that rank “B” above “A” and the number that
rank “A” above “B” is said to be the loss margin of “A”.
(3b) Before the first round, every candidate is designated as a Continuing
candidate.
(3c) In each round, the Continuing candidate with the greatest loss margin
against any other candidate (Continuing or not) is designated as a Defeated
candidate. The rounds shall continue until only one Continuing candidate
remains, who is then Elected.
(4) The city council may adopt additional regulations consistent with this
subsection to implement these standards.

While this is a hair longer than I would prefer (217 words) I am reluctant
to remove the redundancy.

I am not the best person to lead this. Among other things, I am not a US
citizen and it might be a bit weird if a foreigner is trying to mess around
with the way an American city elects its leaders. But I could play a
supporting role.

...

rankedvoting.org

MMV = Maximum Majority Voting
MME = Maximum Majority Election
RHV = Ranked Head-to-Head voting
AVC voting = All Voters Count voting
ABC voting = All Ballots Count voting
EVC voting = Every Vote Counts
CEV = Count Every vote

... DDV = Demolition Derby Voting ?

Cheers,
Daniel

On 7/10/21 9:23 AM, Susan Simmons wrote:

Is there a way of extending River to producing a full social order in a
way that passes LIIA? If so, it'd seem to be strictly better than Ranked
Pairs because River also passes IPDA.

Well, perhaps River fails MAM's immunity to complaints criterion, but
that's rather specific.

-km