This is quite the comeback story- Breed was behind on election day but managed to pull ahead via mail-in and absentee ballots. Also, Ranked Choice voting is very good. (It's opposed by conservatives because vote-splintering is an asymmetric problem that mostly affects the left half of the political spectrum and they benefit from FPTP as a result.)
https://www.kqed.org/news/11674589/...ed-london-breed-on-track-to-be-next-s-f-mayor
https://www.kqed.org/news/11674589/...ed-london-breed-on-track-to-be-next-s-f-mayor
Former state Sen. Mark Leno is expected to concede the extremely close San Francisco mayoral election at a news conference Wednesday afternoon. It would take a vote counting miracle for Leno to overcome the growing lead of San Francisco Board of Supervisors President London Breed.
As of the last vote update on Tuesday afternoon, Leno trailed Breed by 1,861 votes under the city's ranked-choice voting system, with at least 8,000 ballots left to count.
At the end of counting on election night, Breed held a nearly 10 percentage point advantage over Leno in first-place votes. But under the ranked-choice system — which reallocates second- and third-place votes from other candidates to the top two finishers — Leno actually finished the night up by just over 1,000 votes.
It would prove to be the high-water mark for Leno, who saw his lead shrink day-by-day as tens of thousands of additional ballots were counted until Saturday, when Breed regained the lead. She continued to grow that margin to nearly 2,000 votes as of Tuesday afternoon, leading to Leno's expected concession on Wednesday.