# [EM] A "Runoff" type method for resolution of cycles incondorcet

Eric Gorr eric at ericgorr.net
Tue Apr 27 08:07:01 PDT 2004

```At 10:30 AM -0400 4/27/04, Ken Taylor wrote:
>  > At 10:21 AM -0400 4/27/04, Ken Taylor wrote:
>>  >I'm dropping the weakest candidate, as defined by number of first
>>  >choice votes, which causes all their defeats of other candidates
>>  >to be dropped.
>>
>>  What will you do when two or more candidates are tied for least first
>>
>
>I'm not sure. There are probably several different ways to deal with this,
>and I don't think it's very relevant to evaluating the procedure in general.

If you were to drop all candidates tied for least first choice votes,
it seems possible that your method could not claim to be cloneproof.
Two or more clones could evenly split the vote and then all be
eliminated even if they, in combination, had > 50% of the vote,
implying that one of the clones should win.

>What does IRV do if there are two candidates tied for last place in a round?

There is no standard.

If you want to see an IRVist cringe, just ask them what they think it
should be.
It's something they generally don't like to talk about as it destroys
the illusion of IRV being a simple method. The answer does matter as
it can change who wins.

In genuine implementations, the two common methods is to either
select one at random or to drop all of them. Basically, the reason
why these methods are selected is that there is no expectation that
this event will occur or that it will change the winner. However,
this expectation is false and I have several genuine examples
demonstrating this
(http://www.ericgorr.net/library/tiki-index.php?page=BallotArchives).

http://demochoice.org attempts to decide based on prior round vote
totals and, if it cannot, selects randomly.

Of course, one could also employ Steve Eppley's excellent Random
Voter Hierarchy to make the decision.

>What does one do in SSD if there are two defeats that are tied for smallest
>magnitude?

SSD is not cloneproof, so we really only care about CSSD, which is
equivalent to the Beatpath Winner method and is well defined.

--
== Eric Gorr ========= http://www.ericgorr.net ========= ICQ:9293199 ===
"Therefore the considerations of the intelligent always include both
benefit and harm." - Sun Tzu
== Insults, like violence, are the last refuge of the incompetent... ===

```