Kevin, Warren, other FBC freaks, I've recently had an idea for a FBC-complying Margins method.
"Voters rank the candidates, equal-ranking and truncation allowed. (1) Make pairwise comparisons. Treating pairwise defeats by margins that are smaller than or equal to the number of ballots on which both candidates are ranked equal-top as pairwise equalities, eliminate candidates that are not in the smallest non-empty set of candidates that are pairwise undefeated by any outside-the-set candidates. (2)If more than one candidate remains, drop eliminated candidates from the ballots and then delete ballots that make no ranking distinction between remaining candidates, and repeat step 1. (3) Repeat steps 1 and 2 as many times as possible. (If at any stage only one candidate remains then that candidate is the winner.) (4) If after step 3 more than one candidate remains, then with ballots that rank both the candidates in a pairwise comparison equal-top used to modify the defeat margins by counting as whole single votes for the pairwise loser (so that some margins can be negative, but not so that any pairwise defeats can be reversed); change the pairwise defeat by a smallest margin to an equality; and as in step 1 again eliminate candidates that are not in the smallest non-empty set of candidates that are pairwise undefeated by any outside-the-set candidates. (5) If more than one candidate remains, then again drop eliminated candidates from the ballots and then delete ballots that make no ranking distinction between remaining candidates. (6) Keep repeating steps 4 and 5 until only one candidate remains." In common with MDD,ER-Bucklin(whole) I think it meets Majority for Solid Coalitions and Condorcet(Gross). But unlike that method, it meets Independence from Irrelevant Ballots. Chris Benham ---- election-methods mailing list - see http://electorama.com/em for list info
