[EM] Let's play Jenga!

[Kristofer Munsterhjelm]

On 10/01/2017 02:42 PM, Ross Hyman wrote:
> Repeatedly remove the weakest link whose removal leaves at least one
> ranking of all of the candidates in which there is a direct win for the
> higher candidate over the next lower candidate.  When only one such
> ranking exists, elect that ranking of candidates.
>
> This method is different from Tideman Ranked pairs.
> Consider the pair ordering B>D, B>A, C>B, D>C, C>A, A>D.
> The above method produces: D>C>B>A. The Tideman order is C>B>A>D.  The
> Tideman order is better. The Schulze winner is also C.

Warren's Maxtree method is another Ranked-Pairs-like that it might be 
interesting to investigate. The method's logic is akin to:

- Ranked Pairs is similar to Kruskal's algorithm for finding a minimum 
spanning tree in an undirected graph.
- But the graph induced by the Condorcet matrix is directed.
- So use an MST algorithm for weighted graphs instead.
- This algorithm is Chu-Liu-Edmonds and the method becomes max-tree. 
(See Warren's votedesc.pdf for more information)

I've never got around to implementing it, though.