# [EM] DMC, Ties & Eppley's RVH

Eric Gorr eric at ericgorr.net
Fri Sep 2 11:33:05 PDT 2005

```Dave Ketchum wrote:
> On Fri, 02 Sep 2005 08:26:32 -0400 Eric Gorr wrote:
>
>> Dave Ketchum wrote:
>>
>>> On Thu, 01 Sep 2005 14:08:08 -0400 Eric Gorr wrote:
>>> Most of the places for which RVH claims value cannot benefit without
>>> voters accepting it as suitable - give them a black box without
>>> content they can understand with reasonable effort and they properly
>>> choke.
>>
>>
>>
>> Again, what is difficult to understand about the RVH?
>
>
>
> What does it do

Resolve a tie.

> why

Because a tie needs to be resolved.

> and when?

Whenever a method needs to resolve a tie.

>> How would you describe the procedure the RVH uses to select the
>> strict, random ordering of the candidates?
>>
>> Why would the average person not be able to understand the selection
>> of a series of ballots at random?
>>
> Since I do not understand why bother,

Ah, I didn't realize you didn't know how the RVH worked.

> I start wondering what you mean by
> "random".

Let's say that we have the following set of ballots:

60:a>b>c
20:b>c>a
20:c>a>b

There is a 60% chance the tie breaking order would be: a>b>c
There is a 20% chance the tie breaking order would be: b>c>a
There is a 20% chance the tie breaking order would be: c>a>b

If a ballot does not fully define a strict ordering of the candidates,
the orderings of the candidates are kept and another ballot is selected.
Preferences from this new ballot, which do not conflict with previously
kept preferences are kept. Keep going until a strict ordering of the
candidates is found.

Is there anything you do not understand?

If so, please provide your own set of ballots and try to work through it
yourself. Please describe in detail what you think should happen at each
step.

The primary reason why the RVH is better then simply selecting a tied
candidate at random is because it provides a statistical edge to those
candidates who are preferred by a majority of voters.

```