Procedure[edit | edit source]
Ballot use ranges, converted then in ranking, in which candidates can have the same position.
- The votes are normalized, assigning 1 to the greater rating and 0 to the others, and the candidate with the highest sum of points is removed (saved) from the votes.
- Procedure 1 is repeated until only 1 candidate remains. The remaining candidate is eliminated, and those removed (saved) in procedure 1 are added again.
- By repeating procedures 1 and 2, one candidate is eliminated each time and in the end only 1 will remain, the winner.
Difference from IRV[edit | edit source]
Given these ballots:
20: B > A > C 10: A > B > C 29: C > A > B
WIRV makes A wins. IRV make B wins.
10 (or more) people in the third group, realizing C has no chance, strategically decide to insincerely switch their first and second rankings:
20: B > A > C 10: A > B > C 19: C > A > B 10: A > C > B
WIRV and IRV makes A wins.
The strategy shown in the example doesn't change the WIRV result.
Variants[edit | edit source]
WIRRV[edit | edit source]
WIRRV it's WIRV with the following extra rule:
- the weight of the vote is halved every time one of the candidates, supported by the vote in 1st position, is saved. The weight of the votes is restored after finding the loser.
This variant is more resistant to the failures of monotonicity.