I think I'm getting the sieve idea into better focus now. Is the following method is equivalent to Approval Sorted Margins?
Ranked ballots with approval cutoff. Strong defeat = pairwise defeat by higher-approved candidate Strong losers = set of all strongly defeated candidates Provisional set = set of non-strongly-defeated candidates Each provisional winner defeats all higher-approved members of the set. This is Forest's "P" set. Convenient that Provisional starts with P, isn't it? ;-) Marginal defeat: Pairwise defeat of provisional candidate X by strong loser Y under these conditions: (1) Z = the least-approved provisional winner who strongly defeats Y. (2) Approval(X) - Approval(Y) < Approval(Z) - Approval(X) TODO: Need a more succinct description of this. Marginal losers = set of all marginally defeated candidates Strong set = set of candidates neither strongly nor marginally defeated. The least-approved member of the strong set defeats all higher-approved strong candidates and wins the election. The approval winner and the highest-approved member of the Smith set are always strong candidates. I think a good name for this method would be Marginal Ranked Approval Voting (MRAV). I've created a page for it here: http://wiki.electorama.com/wiki/Marginal_Ranked_Approval_Voting One interpretation of the marginal defeat is that a marginal loser doesn't have enough approval "buoyancy" to rise above the strong-defeated candidates, and is peeled off of the edge of the provisional set. Strategy should be similar to Approval Margins and identical in 3-candidate cases. The MRAV strong set could be used for a DFC-like random ballot method. Suggestions? Discussion? -- araucaria dot araucana at gmail dot com ---- Election-methods mailing list - see http://electorama.com/em for list info