Oakland voters have been told more than once this year to “expect the unexpected” in the race to replace outgoing mayor Ron Dellums. Ten candidates seek the office, making for a crowded and diverse field of contenders. Voter support appears to be distributed fairly evenly among the top three candidates, with at least one additional candidate gaining strength in the polls.

This competitive mayoral election occurs in the first year that Oakland voters will use ranked-choice voting (RCV) to elect their representatives in municipal government. RCV was custom-built for competitive elections with more than two candidates. Under the old system, a mayoral race like this one would likely have required two separate elections to select a winner. A June election, in which only a small number of voters typically participate, would have whittled the field down to just two candidates. Then, after a costly and divisive five-month runoff campaign, voters would have selected a winner in November. Now, using RCV, voters will settle the issue with a single trip to the polls in a high-turnout general election.

This year’s RCV election brings both familiar and unfamiliar twists for Oakland voters. On election night, all first-choice rankings in the mayor’s race will be released at the same time as votes cast in non-RCV races. However, Alameda County has chosen to wait run the RCV tally of second and third-choice rankings until most absentee votes have been processed. The first RCV tally will be run no later than Friday, three days after the election. This kind of wait before results are released is nothing new – in the 2006 mayoral election, it took two weeks of waiting for absentee ballots to arrive before Dellums could be officially declared the winner. But the fact that the RCV tally won’t be run immediately means that on election night, voters will learn which candidates are best positioned to win, but not necessarily who the final winner is.

To understand what the preliminary results might mean, it’s useful to review how RCV works. All voters have a single vote, with their RCV ballots counting for one candidate at a time. After ranking their first choice, most voters will also indicate their second and third choices as backups. If a candidate wins a majority of the first-choice rankings, that candidate is declared the winner and the election is over. If no candidate receives that first round majority, then the RCV tally occurs. Last-place candidates are eliminated, and their supporters’ ballots are added to the totals of their next-choice candidate. This “instant runoff” process continues until the winner secures a majority.

It is important to note that the candidate who holds the lead in first-choice rankings after the first round of counting might not win. That candidate could ultimately lose to another who has more widespread support from backers of losing candidates once their alternate choices are counted.

The fact that the lead can change in this way is one of the reasons why Oakland chose to adopt RCV in the first place. A candidate who hopes to represent such a diverse city as Oakland needs to appeal not only to a loyal group of supporters, but also to voters inclined to vote for other candidates as their first choice. The RCV counting process makes sure that the winner of the final “instant runoff” round has exactly that kind of broad representative appeal. The winning candidate will have to garner enough first-choice rankings to make it to the runoff and also pick up enough second and third choices to win a majority.

Once all votes have been counted, the candidate supported by the majority of voters in the final round will emerge as the winner. It might take a few days, and the winner might not be the candidate who looked like the leader on Tuesday night, but the count will be done right. County registrar Dave Macdonald and his staff have done an impressive job of introducing RCV to voters and administering the election. Now it’s time to vote – and to see which candidate best represents the hopes of Oakland’s residents.