Condorcetmenetelmää

Condorcet's method is a system for ranking candidates in an election. It's named after the French philosopher and mathematician Jean-Charles de Borda. The core idea is to compare each candidate against every other candidate in a series of head-to-head contests.

In a Condorcet election, voters rank their preferences for all candidates. Then, for any two candidates, say Candidate A and Candidate B, the method counts how many voters prefer A over B and how many prefer B over A. The candidate who wins the majority of these pairwise comparisons is considered the winner.

If one candidate defeats every other candidate in these pairwise contests, that candidate is the Condorcet winner. This candidate is guaranteed to be the most preferred candidate by a majority of voters when considered in isolation against any opponent.

However, Condorcet's method can sometimes lead to a situation called a Condorcet paradox, where there is no clear winner. This occurs when Candidate A beats Candidate B, Candidate B beats Candidate C, but Candidate C beats Candidate A. In such cyclical preferences, no single candidate emerges as the Condorcet winner. Various tie-breaking rules and alternative Condorcet-consistent methods exist to address these paradoxes. Despite this, the principle of pairwise comparison remains central to its design.