In 2010, Oakland voters went to the polls to cast their votes for the new mayor. When the polls closed, former state senator Don Perata was leading the field of 10 candidates with one third of the vote. In other cities, this would have been a reassuring result for the sought-after position. However, thanks to ranked choice voting, the race was just getting started.

In 2006, Measure O amended Oakland’s city charter to allow ranked choice voting, which is also known as instant runoff voting. This system allows voters to select their top three candidates at the polls. Candidates are eliminated based on the number of first choice votes received. If no candidate receives more than 50 percent of the votes outright, the last place candidate is eliminated, and anyone who ranked that candidate first will have his or her next choice counted instead. The count continues until one candidate receives a majority of the votes. This system eliminated Oakland’s June primary and allowed more candidates into the November election season.

Election night in 2010 was the first year in which a mayoral election would be decided by this method. When the first votes were counted, Perata was in first place; Jean Quan, the then-District 4 City councilmember, was in second; at-large city councilmember Rebecca Kaplan was in third; and Joe Tuman, a political analyst, was in fourth place.

It took nine passes and eight days to decide the mayor’s race that year, as most of the political newcomers were whittled down, and the top four remained in the same order. Then Tuman was bumped out. Then Kaplan. This last step decided the race: over 18,000 of Kaplan’s voters had chosen Quan as their next choice and around 6,400 had chosen Perata, allowing Quan to win the election.

Now, as the 2014 election approaches, candidates are more familiar with the ranked choice voting system. Quan, Kaplan, and Tuman are all back in the race, joined this time by 12 other candidates. The candidates are mixed over whether ranked choice voting helped or hurt them in the last election and how they expect it to affect their campaigns this time.

Ranked choice voting has shaped how some campaigns, like Kaplan’s, approach voters. Traditionally, when campaigning, candidates asked for your only vote. With ranked choice voting, some campaigns may ask for the second or third slot if they are not your first choice. Jason Overman, campaign manager for Kaplan, said that they will ask voters to consider her for any spot on their ballot.“We’re explicitly, obviously, asking for first place votes,” Overman said. “We’re also explicitly asking voters for their second and third place votes, as well.”

Libby Schaaf, the current councilmember for District 4 and a candidate for mayor, won her council seat under ranked choice voting in 2010. Schaaf said she thinks it didn’t affect her race for the District 4 seat significantly because she was the frontrunner throughout the process. “My council election, ranked choice probably didn’t play much of a role,” Schaaf said. “I was in first place with every round of tabulations. Although there were seven candidates in my race, it wasn’t until only three candidates were left that I achieved the 50 percent threshold to win the seat.”

This year, she is holding demonstrations about ranked choice voting at her campaign events to explain how it works to voters.

Joe Tuman, a returning challenger from 2010, called ranked choice voting “a mixed bag.” He said, to be successful, a candidate needs to reach as many voters as he or she can reach, say the same thing to every audience, and offer real solutions. “Campaigning is difficult, regardless,” Tuman said.

(Perata could not be reached for comment, and Quan did not respond to requests for comment.)

Many of the competitors in Oakland’s campaign say that ranked choice voting encourages candidates “to run more positive campaigns,” as Overman puts it. “Under the old system,” Overman wrote via e-mail, “some candidates relied on the stale campaign tactics of the past where they’d attack their opponents to get ahead. Under ranked-choice voting, there’s much greater incentive to tell the voters what’s good about you rather than sling mud against your opponents.”

Mayoral candidate Dan Siegel, a civil rights lawyer, agrees. “I think that one of the impacts of ranked choice voting is that the candidates are less critical of one another because they don’t want to anger the supporters of the other candidates,” he said. “So if I want Jean Quan’s supporters to give me their second choices, I have to temper what I have to say about Jean or to Jean.”

Overman said that another advantage of this system is that it saves taxpayers money, because there is no primary election.

“If there were run-off elections,” Siegel agreed, “that would be very costly and it would favor the candidates with the most money.”

Similarly, said Schaaf, “As a candidate, I like that I only have to campaign and raise money for one election.”

Rob Richie, Executive Director of FairVote, an organization that advocates for ranked choice voting, agrees. This system “allows for a single, concentrated election season,” he said. Richie said that it also gives candidates incentives to reach out to all voters. “Every candidate has to treat every voter as a swing voter,” he said.

“I do think that the candidates that have had the greatest success in city elections with ranked choice voting are the strong candidates that get out into the community more, talk to more people, get to more community events, do more local debates, and find a way to connect with people,” Richie said. “It’s not just doing that—you have to do it well.”

However, some say there are some downsides to the system. “Because of the concern of not wanting to get anybody upset,” said Siegel, “I think the candidates tend to be kind of mushy, in terms of what they have to say, instead of being as sharp as they could be.”

And when you have a field as wide as it has been in both the 2010 and the 2014 elections, Tuman said, any individual candidate is likely to get drowned out. He said that it can be frustrating for voters to have to focus on multiple candidates when they’re used to a “dyad of choices.”

Schaaf said that she has heard similar concerns on the campaign trail—“That it’s a lot of work to become knowledgeable enough about such a large field of candidates that you can make three good, informed choices.”

Ranking candidates, instead of just picking one, may also bewilder some voters. “A lot of people find it confusing, and we are educating as many people as possible about how it works,” Schaaf said. For example, she continued, “People don’t realize that casting a second or third choice in no way subtracts the power of their vote for their first choice. People are also surprised to learn that ballots often get eliminated and make it easier for the remaining candidates to win.”

Siegel has also run into some voters who aren’t clear on the system; for example, he’s heard someone say that the second choice vote is the one that really counts. “I just tell people, ‘Just put your top choice first, your second choice second, and your third choice third, and that’s the way to maximize the impact of your vote,’” Siegel said.

Oakland isn’t the only city to have ranked choice voting, but it’s one of the few in the United States. “We’re talking about a dozen cities that are actively using it and maybe four that have passed it and are in the transitioning to implementation phase,” Richie said. Three areas have had it and dropped it: Burlington, Vermont; Pierce County, Washington; and Aspen, Colorado.

So far, ranked choice voting has only been used in municipal and county-wide systems. It isn’t used in federal elections, like the race for president. Richie says that’s because it hasn’t been widely proven yet. “I think Americans want to see things in action,” he said. Before they will accept it for a federal election, he said, people “want to see it in play more often.”

The system hasn’t been used in state elections, either. California Secretary of State candidate Pete Peterson, who recently spoke at UC Berkeley during a debate, says that he wants “to see more of it at the more local level. I am skeptical about how it can scale.” Peterson likes the argument that ranked choice voting increases participation but would still like to see it more at the local level “before I’d even consider ramping it up,” he said.

Technical challenges could also prove to be a problem, Richie said. He said that converting machines to handle ranked choice voting is a slow process. “To adapt current machines, you have to go through the certification process, which is hard,” he said. (The California Secretary of State’s office handled the certification process for Alameda County’s machines, Richie said.)

According to Richie, Memphis, the largest city to approve ranked choice voting, hasn’t implemented it yet because the voting machines they currently use would have to be converted, a cost he says they will pay when they replace their older touch screen machines with optical scan machines.

It’s unclear if, in Oakland’s upcoming mayoral race, the ranked choice voting system will have as profound an effect on the outcome as it did in 2010. But in the meantime, many of this year’s candidates have already adapted to campaigning under it. While it may seem awkward to actively campaign to be a voter’s second choice, Siegel says he doesn’t see it that way. “Spend a couple of weeks talking to strangers on the BART platform,” he said, “and you’re either going to get over your shyness or your awkwardness very quickly, or decide that there is probably something else you should be doing.”