Instant-Runoff Voting

What the ballot looks like with Instant-Runoff Voting

Instant-Runoff Voting is a ranked-choice voting system, meaning voters rank the candidates from their most preferred to their least preferred.

Here is an example of a ranked-choice ballot.

Ranked ballots on StrawPoll.vote work by dragging the options, but this is not the case with physical ballots used in many elections, such as for government officials. Physical ranked ballots generally require that the voters fill in a separate bubble for their first choice, second choice, third choice, etc.

How the winner is determined

To determine the winner using Instant-Runoff Voting, you start by giving a vote to the candidate ranked highest on each ballot. If any candidate receives more than 50% of the votes, they are declared the winner. If no candidate gets a majority of votes, the candidate with the fewest votes is removed from every ballot, and the process restarts.

Let's walk through an example. The initial allocation of votes for a population of 100 people is as follows:

Since no one received more than 50% of the vote, the candidate with the fewest votes, Alice, is removed from every ballot and the vote is recalculated.

Still no candidate has crossed the 50% threshold, so we remove the weakest candidate, Dave, and recalculate.

Bob, narrowly beating Carol, emerges victorious!

Where Instant-Runoff Voting performs best

As a ranked-choice voting system, Instant-Runoff Voting performs best when the voters have a ranked preference between the options, but only when there are no more than two strong candidates.

When there are two major candidates and many minor candidates, Instant-Runoff Voting does well at redistributing the votes from the minor candidates to the major candidates and ensures that whichever of the two major candidates is preferred by a majority of voters is elected.

Where Instant-Runoff Voting performs worst

Instant-Runoff Voting does not perform well when there are more than two major candidates. Since it is not a Condorcet voting system, it can (and often does) elect a candidate that would lose in a head-to-head election against other candidates. This happens when candidates who would go on to do well are eliminated prematurely.

As a ranked-choice voting system, Instant-Runoff Voting should not be used in situations where the options are mutually exclusive to the voter. For example, when looking at the number of senior citizens in a population, a voter will either fall into the bucket of "Below 65" or "65 and Over". It should also not be used when voters unlikely to have a ranked preference between options.

Try Instant-Runoff Voting

Create your own poll and send it to your friends to see how Instant-Runoff Voting performs.

Learn about other voting systems