New York City's ranked choice voting: How it works

Ranked choice voting was invented in Europe in the 1850s, adapted in the 1870s by an MIT professor to pick an instant runoff winner, and didn’t come to New York City’s citywide primary and special elections until 2021. The system will be how the next mayor is chosen.

Here’s how it works.

Each of the first-choice votes is tabulated. If the top candidate gets over 50% of those first-choice picks, that candidate is declared winner.

But if none of the candidates has over 50% of those first-choice votes, the tabulation keeps going in rounds.

“At the end of each round, the last-place candidate is eliminated and voters who chose that candidate now have their vote counted for their next choice,” the city’s Board of Elections says. “Your vote is counted for your second choice only if your first choice is eliminated. If both your first and second choices are eliminated, your vote is counted for your next choice, and so on.”

That process keeps going — until just two candidates are left. The one with the most votes wins.

Ranked choice voting, enacted in 2019, replaced the former system in which the city held an entire new election — a runoff — if no candidate got 50% in the election.

By Matthew Chayes

matthew.chayes@newsday.comchayesmatthew

Matthew Chayes, a Newsday reporter since 2007, covers New York City.