An illustrated guide to ranked-choice voting

Armin Samii
Nov 18 · 3 min read

A standard election allows you to vote for one candidate. Your ballot looks like this:

An election with four candidates: Vanilla, Strawberry, Banana, Blackberry. Strawberry is checked.
An election with four candidates: Vanilla, Strawberry, Banana, Blackberry. Strawberry is checked.

The results of such an election are easy to understand, too:

Vanilla wins! But hey, that’s not fair! Most people preferred some fruity flavor over Vanilla. But the fruity flavors split the vote, allowing Vanilla to take the lead.

In a ranked-choice voting election, your ballot looks more like this:

Like the above image, but strawberry is ranked #1, banana #3, and blackberry #2
Like the above image, but strawberry is ranked #1, banana #3, and blackberry #2

Instead of voting for your top choice, you’re voting for your top choices. You want Strawberry, but would rather have any fruity flavor over Vanilla. In this RCV election, Vanilla can’t just have the most votes: it needs more than 50% of the votes. If no candidate receives more than half the votes, the candidate with the lowest number of votes is eliminated. If your top candidate is eliminated, your vote isn’t wasted: your second-choice candidate now gets your vote.

RCV is spreading. In 2018, it was used in Maine for the first federal election in the USA. New York City just adopted it. San Francisco has been using it since 2004. Australia has been using it since 1918.


Ranked-choice voting proceeds round-by-round. How can we visualize each of these rounds? Let’s see some example.

As an interactive bar chart

In the first round, Vanilla had the most votes, but didn’t hit the required threshold of 50%. Banana was eliminated, and its votes were split between the other three candidates (shown in pink). Finally, Strawberry was eliminated, and most of its votes went to Blackberry, making Blackberry the ultimate winner (shown in blue).

[View this bar chart live on rcvis.com]

As a Sankey diagram

The same election can be visualized as a Sankey diagram. The thicknesses of the lines flowing between rounds shows the number of votes that moved from one candidate to the next.

[View this Sankey diagram live on rcvis.com]

As a table, round-by-round

Maybe you prefer numbers? Here’s the number of votes and the changes that happened each round.

[View this round-by-round table live on rcvis.com]

As a table, by candidate

Perhaps you want to see a breakdown of what happened to a single candidate. You can drill down to see how Blackberry’s votes changed in each round, and where those votes came from:

[View this candidate-by-candidate table live on rcvis.com]

Which is your favorite visualization?

The biggest complaint I’ve heard about Ranked-Choice Voting is that it’s too complicated to understand the results. I’ve spent the last year building these visualizations to make RCV results more understandable. Which makes the most sense to you? Comment below!

Learn more about RCV

Gratitude

Ranked-Choice Voting Resource Center
FairVote
Sohan Murthy’s Medium Post

The visualizer project is hosted open-source on github. Want to contribute? Drop me a line at armin@rcvis.com.

Armin Samii

Written by

Building products using computer graphics and data visualizations. Ranked-Choice Voting enthusiast. Pittsburgh, PA.

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