But many people are still confused about how this type of voting works.
This is what San Francisco voters will see when they vote for mayor -- the ballot asks you to pick a first choice, second choice and third choice.
But once you pick them, then what? How does the ranked choice voting algorithm come up with the winner?
Watch the video above for an explanation from ABC7 News Anchor Kristen Sze.
Take a look at the latest stories and videos about the election.
Hippo says, “San Francisco politics getting ugly.” pic.twitter.com/UfLS4cwqYH— Lyanne Melendez (@LyanneMelendez) May 10, 2018