Dear Mike, you wrote (1 April 2005): > SSD isn't a special case of BeatpathWinner. SSD > and BeatpathWinner are two dilfferent methods that > can give two different outcomes wilth the same > ballot-set, as in the example that I posted yesterday. > In an example such as that, BeatpathWinner and SSD > give different results. There isn't come version > of BeatpathWinner that is SSD.
But in your example you argue that BeatpathWinner is indifferent between A and D while SSD chooses D. Therefore, your example doesn't demonstrate that "SSD isn't a special case of BeatpathWinner". To demonstrate that "SSD isn't a special case of BeatpathWinner" you would have to post an example where SSD chooses a candidate who isn't a potential BeatpathWinner winner. But this is not possible because also SSD has this property (which makes SSD a tie-breaking strategy for the Schulze method): If p(z)[A,B] > p(z)[B,A], then candidate B must be elected with zero probability. Markus Schulze ---- Election-methods mailing list - see http://electorama.com/em for list info
