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<p>Yes, I don't know where my "Sincere Defense" brain-fart came
from. I meant *Minimal Defense*. (I corrected it below).<br>
<br>
Chris B.<br>
<br>
</p>
<div class="moz-cite-prefix">On 1/06/2024 11:34 am, Chris Benham
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:4cd62221-fb17-4a13-bd3b-8ad50364cfab@yahoo.com.au">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
It doesn't talk about just any "Condorcet winner". It says that
if A is the sincere CW and more than half the voters vote A above
B, then the voters who prefer B to A can't make B win just by
truncating.<br>
<br>
But maybe they can if less than half the voters vote A over B
(with A still being the sincere CW and pairwise-beating B) and
maybe they can by order-reversal Burial.<br>
<br>
Minimal Defense says that if more than half the voters prefer A
to B, they can stop B from winning by voting A over B and
truncating against B. From a Kevin Venzke webpage:<br>
<br>
<a class="moz-txt-link-freetext"
href="https://votingmethods.net/em2005" moz-do-not-send="true">https://votingmethods.net/em2005</a><br>
<br>
<blockquote type="cite"><a name="critmd"
style="color: rgb(0, 0, 0); font-family: "Times New Roman"; font-size: medium; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(208, 208, 208); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;"
moz-do-not-send="true">
<h3><b>Minimal Defense</b>.<span> </span><i>(Due to Steve
Eppley.)</i></h3>
<p><i>If more than half of the voters rank candidate A above
candidate B, and don't rank candidate B above anyone, then
candidate B must be elected with 0% probability.</i></p>
</a>
<p
style="color: rgb(0, 0, 0); font-family: "Times New Roman"; font-size: medium; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(208, 208, 208); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;"><a
name="critmd" moz-do-not-send="true">Steve Eppley has
defined and discussed Minimal Defense<span> </span></a><a
href="http://alumnus.caltech.edu/~seppley/"
moz-do-not-send="true">here [broken link]</a><span> </span>and<span> </span><a
href="http://alumnus.caltech.edu/~seppley/Strategic%20Indifference.htm"
moz-do-not-send="true">here [broken link]</a>. Satisfaction
of this criterion implies compliance with Mike Ossipoff's<span> </span><i>strong
defensive strategy criterion</i>, although the reverse is
not necessarily true. That criterion can be found<span> </span><a
href="http://www.barnsdle.demon.co.uk/vote/stfree.html"
moz-do-not-send="true">here [broken link]</a>.</p>
<p
style="color: rgb(0, 0, 0); font-family: "Times New Roman"; font-size: medium; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(208, 208, 208); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">Note
that the ballot must accept all preference orders; in
particular, the voter must be able to rank multiple candidates
above no one (usually by truncation), and to<span> </span><i>strictly</i><span> </span>rank
any number of candidates. If the word "strictly" were dropped,
then<span> </span><a
href="https://votingmethods.net/em2005#methappr"
moz-do-not-send="true">Approval</a><span> </span>would
satisfy, as could other methods using a "limited slot" ballot.
(<a href="https://votingmethods.net/em2005#methappr"
moz-do-not-send="true">Approval</a><span> </span>satisfies
Mike Ossipoff's<span> </span><i>weak defensive strategy
criterion</i><span> </span>for this reason.) In my opinion,
the word "strictly" should be dropped, since<span> </span><a
href="https://votingmethods.net/em2005#methappr"
moz-do-not-send="true">Approval</a><span> </span>can already
be made to satisfy Minimal Defense just by allowing the voter
to number his approved candidates, without analyzing the
ballot any differently.</p>
<p
style="color: rgb(0, 0, 0); font-family: "Times New Roman"; font-size: medium; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(208, 208, 208); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">Minimal
Defense deals with the issue of what a majority need to do to
get their opinion counted. Specifically, if they are united in
preferring candidate A to candidate B, all they have to do is
not rank B. They need not do anything special regarding A. For
instance, on these ballots:</p>
<p
style="color: rgb(0, 0, 0); font-family: "Times New Roman"; font-size: medium; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(208, 208, 208); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;"><font
face="Courier">49 B<br>
13 C>A<br>
13 D>A<br>
13 E>A<br>
12 F>A<br>
</font></p>
<p
style="color: rgb(0, 0, 0); font-family: "Times New Roman"; font-size: medium; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(208, 208, 208); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">The
A>B voters (i.e., the voters preferring A to B) are a
majority, and do not rank B at all, so that Minimal Defense
guarantees that B won't win. However, candidate B is the
winner in e.g.<span> </span><a
href="https://votingmethods.net/em2005#methfpp"
moz-do-not-send="true">Plurality</a>,<span> </span><a
href="https://votingmethods.net/em2005#methirv"
moz-do-not-send="true">Instant Runoff</a>, and<span> </span><a
href="https://votingmethods.net/em2005#methdsc"
moz-do-not-send="true">Descending Solid Coalitions</a>.
Under these methods, if the A>B majority want to prevent B
from being elected, they need to insincerely raise candidate A
in their rankings.</p>
<p
style="color: rgb(0, 0, 0); font-family: "Times New Roman"; font-size: medium; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(208, 208, 208); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">A
more general way to view this problem is by noting that this
election is primarily a contest between A and B. In that
light, it would be very undesirable for the election method to
elect the<span> </span><i>wrong one</i><span> </span>of these
two. Minimal Defense ensures that the method can't be
"confused" by the introduction of weaker candidates preferred
to the major candidates.</p>
<p
style="color: rgb(0, 0, 0); font-family: "Times New Roman"; font-size: medium; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: rgb(208, 208, 208); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">As
for the methods which satisfy Minimal Defense,<span> </span><a
href="https://votingmethods.net/em2005#methsch"
moz-do-not-send="true">Schulze</a><span> </span>elects A in
the above scenario (as would any<span> </span><a
href="https://votingmethods.net/em2005#methcond"
moz-do-not-send="true">Condorcet method</a>), and<span> </span><a
href="https://votingmethods.net/em2005#methcdtt"
moz-do-not-send="true">Equal Majorities</a><span> </span>elects
either C, D, E, or F. (This is because all candidates besides
B are in the CDTT; when<span> </span><a
href="https://votingmethods.net/em2005#methrb"
moz-do-not-send="true">Random Ballot</a><span> </span>is
used to break the tie, only these four candidates have any
first preferences.<span> </span><a
href="https://votingmethods.net/em2005#methmmpo"
moz-do-not-send="true">Minimum Opposition</a><span> </span>gives
the same result, incidentally, although it doesn't satisfy
Minimal Defense when there are more than three candidates.)</p>
</blockquote>
<br>
<br>
<div class="moz-cite-prefix">On 1/06/2024 8:38 am, Closed Limelike
Curves wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CA+euzPi+VNW5xdJxPV9dCVx-q38SX8ar=E-CZWrRA+=nDuiNdg@mail.gmail.com">
<meta http-equiv="content-type"
content="text/html; charset=UTF-8">
<div dir="auto">OK, so SFC prevents offensive truncation from
defeating the Condorcet winner, while minimal defense provides
a simple way to stop order-reversal?</div>
<div><br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Fri, May 31, 2024 at
4:01 PM Michael Ossipoff <<a
href="mailto:email9648742@gmail.com"
moz-do-not-send="true" class="moz-txt-link-freetext">email9648742@gmail.com</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote"
style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="auto">Evidently, then, SFC merely says that the
candidate can’t win without order-reversal, while
Minimal-Defense says he can’t win at all if the minimal
defensive-strategy is used.</div>
<div dir="auto"><br>
</div>
<div dir="auto">It seems to me that Eppley’s
Minimal-Defense was the votes-only criterion based on
SDSC.</div>
<div dir="auto"><br>
</div>
<div dir="auto">…& that SDSC was the original,
preference-&-sincerity version.</div>
<div dir="auto"><br>
</div>
<div dir="auto">I preferred preference-&-sincerity
because of its universal applicability, where votes-only
had to stipulate a balloting.</div>
<div><br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Fri, May 31, 2024
at 12:33 Chris Benham <<a
href="mailto:cbenhamau@yahoo.com.au"
target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">cbenhamau@yahoo.com.au</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote"
style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div>
<p><font size="4">Why are we having a public
discussion about a voting method criterion
without anyone giving its definition, and with
apparently most of the participants in the
discussion knowing nothing about it besides
its name?</font><br>
<br>
<a
href="https://electowiki.org/wiki/Strategy-free_criterion"
target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">https://electowiki.org/wiki/Strategy-free_criterion</a><br>
<br>
</p>
<blockquote type="cite">
<p
style="margin:0.5em 0px;color:rgb(32,33,34);font-family:sans-serif;font-size:14px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;word-spacing:0px;white-space:normal;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><font
size="4">The<span> </span><b>strategy-free
criterion</b><span> </span>is a<span> </span><a
href="https://electowiki.org/wiki/Voting_system_criterion"
title="Voting system criterion"
style="text-decoration:none;color:rgb(51,102,204);background:none"
target="_blank" moz-do-not-send="true">voting
system criterion</a><span> </span>for
evaluating<span> </span><a
href="https://electowiki.org/wiki/Voting_system" title="Voting system"
style="text-decoration:none;color:rgb(51,102,204);background:none"
target="_blank" moz-do-not-send="true">voting
systems</a>.</font></p>
<h2
style="color:rgb(0,0,0);margin:1em 0px 0.25em;padding:0px;overflow:hidden;border-bottom:1px solid rgb(162,169,177);font-weight:normal;font-family:"Linux Libertine",Georgia,Times,serif;line-height:1.375;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;word-spacing:0px;white-space:normal;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><font
size="4"><span
id="m_-5229649647197194953m_-2555177099667943496Definitions">Definitions</span></font></h2>
<p
style="margin:0.5em 0px;color:rgb(32,33,34);font-family:sans-serif;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;word-spacing:0px;white-space:normal;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><font
size="4">A sincere vote is one with no
falsified preferences or preferences left
unspecified when the election method allows
them to be specified (in addition to the
preferences already specified).</font></p>
<p
style="margin:0.5em 0px;color:rgb(32,33,34);font-family:sans-serif;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;word-spacing:0px;white-space:normal;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><font
size="4">One candidate is preferred over
another candidate if, in a one-on-one
competition, more voters prefer the first
candidate than prefer the other candidate.</font></p>
<p
style="margin:0.5em 0px;color:rgb(32,33,34);font-family:sans-serif;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;word-spacing:0px;white-space:normal;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><font
size="4">If one candidate is preferred over
each of the other candidates, that candidate
is called "Condorcet candidate" or
"Condorcet winner".</font></p>
<h2
style="color:rgb(0,0,0);margin:1em 0px 0.25em;padding:0px;overflow:hidden;border-bottom:1px solid rgb(162,169,177);font-weight:normal;font-family:"Linux Libertine",Georgia,Times,serif;line-height:1.375;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;word-spacing:0px;white-space:normal;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><font
size="4"><span
id="m_-5229649647197194953m_-2555177099667943496Statement_of_criterion">Statement
of criterion</span></font></h2>
<blockquote
style="background:rgb(249,249,249);border-left:4px solid rgb(234,236,240);padding:8px 32px;color:rgb(32,33,34);font-family:sans-serif;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;word-spacing:0px;white-space:normal;text-decoration-style:initial;text-decoration-color:initial">
<p style="margin:0px"><font size="4">If a
Condorcet candidate exists, and if a
majority prefers this candidate to another
candidate, then the other candidate should
not win if that majority votes sincerely
and no other voter falsifies any
preferences.</font></p>
</blockquote>
<p
style="margin:0.5em 0px;color:rgb(32,33,34);font-family:sans-serif;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;word-spacing:0px;white-space:normal;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><font
size="4">In a ranked method, it is nearly
equivalent to say:</font></p>
<blockquote
style="background:rgb(249,249,249);border-left:4px solid rgb(234,236,240);padding:8px 32px;color:rgb(32,33,34);font-family:sans-serif;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;word-spacing:0px;white-space:normal;text-decoration-style:initial;text-decoration-color:initial">
<p style="margin:0px"><font size="4">If more
than half of the voters rank<span> </span><i>x</i><span> </span>above<span> </span><i>y</i>,
and there is no candidate<span> </span><i>z</i><span> </span>whom
more than half of the voters rank above<span> </span><i>x</i>,
then<span> </span><i>y</i><span> </span>must
not be elected.</font></p>
</blockquote>
</blockquote>
<font size="4"><br>
I think this evolved into the Minimal Defense
criterion, the "votes-only version" of which
says that if more than half the voters vote A
over B and B no higher than equal-bottom then B
can't win.</font></div>
</blockquote>
</div>
</div>
<div>
<div class="gmail_quote">
<blockquote class="gmail_quote"
style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div><br>
<br>
<br>
<br>
<div>On 31/05/2024 9:46 pm, Michael Ossipoff
wrote:<br>
</div>
<blockquote type="cite">
<div dir="auto">Some time ago, I wrote a
criterion that I called
Strategy-Free-Criterion (SFC).</div>
<div dir="auto"><br>
</div>
<div dir="auto">Is that what you were referring
to?</div>
<div dir="auto"><br>
</div>
<div dir="auto">It was about a circumstance in
which wv Condorcet is strategy-free. At that
time, autodeterence hadn’t been considered.</div>
<div dir="auto"><br>
</div>
<div dir="auto">SFC didn’t catch-on, & I
haven’t heard mention of it lately, & so I
don’t know it’s definition. But wv Condorcet
is strategy-free in a meaningful sense.</div>
<div><br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Fri,
May 31, 2024 at 05:07 Michael Ossipoff
<<a
href="mailto:email9648742@gmail.com"
target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">email9648742@gmail.com</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote"
style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;padding-left:1ex;border-left-color:rgb(204,204,204)">
<div><br>
</div>
<div><br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On
Wed, May 29, 2024 at 14:15 Closed
Limelike Curves <<a
moz-do-not-send="true">closed.limelike.curves@gmail.com</a>> </div>
<div dir="ltr" class="gmail_attr">Ppwrote:<br>
</div>
<blockquote class="gmail_quote"
style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;padding-left:1ex;border-left-color:rgb(204,204,204)">
<div dir="ltr">
<div>I'm trying to work out how
the strategy-free criterion
actually relates to strategy,
because it just sounds like it
means the majority-Condorcet
criterion ("if a candidate
majority-beats every other, they
have to win if everyone is
honest"). <a
class="gmail_plusreply"
id="m_-5229649647197194953m_-2555177099667943496m_3749243691140155182m_3764866669967271283m_3208403200595893820plusReplyChip-1"
moz-do-not-send="true">@Michael
Ossipoff</a> ?</div>
</div>
</blockquote>
</div>
</div>
<div dir="auto"> Closed, isn’t
“Strategy-Free Criterion” your new name
for FBC.</div>
<div dir="auto"><br>
</div>
<div dir="auto">It’s a very inaccurate
name. FBC-complying methods aren’t
strategy-free in any sense.</div>
<div dir="auto"><br>
</div>
<div dir="auto"> But they’re free of any
need for *drastic* defensive strategy
(favorite-burial or any defensive
order-reversal).</div>
<div dir="auto"><br>
</div>
<div dir="auto">You want strategy-free?
The wv Condorcet methods, such as RP(wv)
& MinMax(wv), are strategy-free in a
meaningful sense…effectively free of
need for any defensive strategy…due to
their autodeterence.</div>
</blockquote>
</div>
</div>
</blockquote>
</div>
<div>
<blockquote type="cite"> <br>
<fieldset></fieldset>
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