Talk:Schulze STV

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The description of the algorithm is different from the description that Schulze gives in his paper schulze2.pdf, there he talks about possible winning sets and the strongest path through a graph, and here it's described as moving votes, for example "51 prefer Both to Brad (assign 19.5 to Andrea and 31.5 to Carter)". It might be that this are just two different ways to describe the same algorithm? But it's not very clear to me that this is the case. Capitol (talk) 21:27, 24 June 2013 (UTC)[reply]

I was also confused about this apparent discrepancy, but looking at Schulze's paper, I believe the two are referring to the same thing. I'm no expert on anything vaguely relevant to this discussion, but p. 37 appears to describe a calculation where voter's preferences are distributed to maximise the number of votes assigned to the candidate with the fewest votes:

${\displaystyle N[{a_{1},...,a_{M}},b]}$ ... is the largest value such that there is a ${\displaystyle t}$ ... such that ... ${\displaystyle \sum _{i=1}^{N_{W}}t_{ij}\geq N[{a_{1},...,a_{M}},b]}$

where ${\displaystyle \sum _{i=1}^{N_{W}}t_{ij}}$ is the number of votes assigned to each candidate. Obviously, this can be achieved by (if possible) assigning the same number of votes to all candidates being considered, as the article states. --RunasSudo (talk) 23:28, 3 September 2015 (UTC)[reply]

Based on the editor's comment the removed sentence (about who invented this method) probably would be acceptable to them if it were moved to a "History" section. The editor's comment implies that it just isn't appropriate in the "Summary" section. And I agree; people don't want to read historical information before the topic itself has been described. VoteFair (talk) 18:25, 4 October 2011 (UTC)[reply]

If I have this right, Schulze STV is effectively determining if a graph has a path no greater than the minimum traversal path, by way of needing to discover the minimum traversal path. The approach does reduce the number of direct pairwise computations necessary (unless you accidentally stumble upon the Condorcet outcome, CPO-STV must compute all of them), but it still does have to compute the same information by a different method (i.e. depending on the order in which you carry out the computations, it is possible you will not have enough information to determine the outcome until you have performed every possible computation). I don't think you can even verify the outcome without performing all the computations, when there's a cycle involving all possible outcomes. This is just the traveling salesman problem. John Moser (talk) 21:24, 18 May 2021 (UTC)[reply]

The Schulze tie-breaker is a shortest path problem, not a travelling salesman problem. It might happen that the shortest path goes through all nodes; but this is not a requirement. Markus Schulze 12:31, 19 May 2021 (UTC)[reply]

This article discusses and obscure voting rule, which is (I) not used in practise (II) not mentioned in any academic paper (III) not mentioned by anyone except the creator of the method (IIII) extremely hard to grasp and badly described. Is this article still up to the modern Wikipedia standard? 2003:CC:CF35:8700:C803:FFB4:789D:5936 (talk) 17:14, 25 September 2022 (UTC)[reply]

@MarkusSchulze Does Schulze STV have any notable stable winner set (or local stability) properties? –Maximum Limelihood Estimator 01:25, 22 April 2024 (UTC)[reply]

On page 409 of the latest version of my paper, I introduce the "Smith criterion for multi-winner elections". Markus Schulze 20:06, 22 April 2024 (UTC)[reply]

Oh wow, that's super interesting—thank you so much! :) –Maximum Limelihood Estimator 03:51, 23 April 2024 (UTC)[reply]