Page "Two-round system" Paragraph 41

The exhaustive ballot ( EB ) is similar to the two round system, but involves more rounds of voting rather than just two.

If no candidate receives an absolute majority in the first round then the candidate ( s ) with the fewest number of votes is eliminated and excluded from further ballots.

The process of exclusion and reballot continues until one candidate has an absolute majority.

Because voters may have to cast votes several times, EB is not used in large-scale public elections.

Instead it is used in smaller contests such as the election of the presiding officer of an assembly ; one long-standing example of its use is in the United Kingdom, where local associations ( LCAs ) of the Conservative Party use EB to elect their prospective parliamentary candidates ( PPCs ).

EB often elects a different winner from runoff voting.

Because the two round system excludes more than one candidate after the first round, it is possible for a candidate to be eliminated who would have gone on to win the election under EB.