IRV allows voters to rank candidates in order of preference (i.e. first, second, third, and so on). To determine the winner, the first-place choices on all the ballots are counted. If any candidate receives a majority of first choices, he or she is elected. If no candidate has a majority, a series of runoffs are simulated, using each voter’s preferences as indicated on the ballot. The candidate who received the fewest first choices is eliminated, and the voters who ranked the eliminated candidate first have their votes counted towards their second choice — just as if they were voting in a traditional runoff election. If any candidate now has a majority of votes, that candidate wins. Otherwise, the candidate with the fewest first-choices is successively eliminated, and the votes for that candidate are redistributed, until a candidate reaches a majority and wins.
This flowchart summarizes the process:
