Ranked-choice voting (RCV) is getting a test on bigger stages these days, with the Mayor’s race in San Francisco and the upcoming statewide primaries in Maine now making use of it.

SF used RCV on Tuesday in the race for Mayor, and as of now, the results remain extremely close, with some stories suggesting it might be a week before the outcome is certain.  At the moment, according to this SF Chronicle story, the candidate who was the first choice of a plurality of voters — London Breed  –will not become Mayor, because after the vote-transfer process, another candidate — Mark Leno — has moved ahead.  Leno specifically campaigned late in the day with another candidate who encouraged each others’ supporters to rank them as their second choice, and this use of the incentives RCV creates appears to have paid off:

“London Breed is clearly the first choice among a plurality of voters, but what we’re learning — again — is that in the end, ranked choice will matter most in this election,” said John Whitehurst, a Democratic political strategist who isn’t involved in any of the mayoral campaigns.

Less than a month before election day, Kim and Leno encouraged each other’s supporters to list the other as their second-place choice, appearing on campaign fliers and political advertisements together. The strategy paid off for Leno, who received a whopping 77 percent of Kim’s second-place votes in the first round of ranked choice counting, more than the campaign had been expecting.

This is apparently the first time in SF’s experience with RCV that two major candidates have teamed up this way.  As more experience with RCV mounts, including the statewide primaries next week in Maine, it will be important to see how voters assess this alternative system of voting.