Dodgson's method

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Dodgson's method is an electoral system based on a proposal by mathematician Charles Dodgson, better known as Lewis Carroll. The method searches for a majority-preferred winner; if no such winner is found, the method proceeds by finding the candidate who could be transformed into a Condorcet winner with the smallest number of ballot edits possible, where a ballot edit switches two neighboring candidates on a voter's ballot.

This classic Condorcet-consistent system, though computationally complex, was defined in Dodgson's A Method of Taking Votes on More an Two Issues pamphlet. It appeared in March 1876, printed by the Clarendon Press, Oxford and headed “not yet published”.