They all stayed, for all three days. They heard from experts and interest groups. They took a lot of notes and they did a lot of talking.
They went into it with a wide variety of views, but they came out with recommendations that all had "supermajority" support. That is, 80% or more of the participants were in favour.
What other process can credibly claim anything near as much?
Right at the start, the facilitator, Anna Curnow, said to them, "There is no one here who's going to tell you what to think. If someone is trying to do that, let me know and I'll stop it."
Curnow said the exercise would work if they were "curious, engaged, collaborative, open-minded, courteous and analytic" and from the start those values prevailed.
It was remarkable. You want some good news about political decision-making? This was it. And the process has a name: deliberative democracy.
The topic was the future of A.F. Thomas Park, better known as the home of the Takapuna Golf Club, in Wairau Valley on the North Shore.
It's public land and the council is going to convert part of it to a wetland area, to serve as a flood detention sink. But when that work is done, it will be up to the Kaipātiki Local Board to decide what to do with the rest of the land.
The golf club has a driving range and 18-hole course there now, while archery and bowls also use some of the land.
And there's the Eventfinda Stadium, which is home to gymnastics, basketball and many other sports and community groups. One more flood, even if it barely covers the special floor, will see the stadium lose its insurance cover and have to close.
There's been public consultation about what to do, which gained more than 5000 submissions. That's a lot, for a local issue. But the local board wanted to dig deeper, so it called in Curnow's company, Decision Works.
Participants were chosen randomly, in a process that ensured the group's demographic profile matched that of the North Shore suburbs.
A fifth of them were under 30 and slightly fewer were over 65. Just over half said they were ethnically European, 11 identified as Asian (including South Asian), four Māori, four Pasifika and there were three from elsewhere (some identified with more than one ethnicity).
They seemed quite different from the usual crowd at a public meeting on an issue like this. Less demanding, less convinced they had a right to be demanding.
Day one was devoted to briefings and group dynamics.
"Today," Curnow said, "I want you to stay on receive." Ask questions and soak it all up.
She introduced them to "brain biases" and "critical thinking". Council officials explained their strategy for managing floods and sport and recreation experts talked about popular trends.
Golf came up all the time and there were many group exercises, aimed not only at clarifying what people thought, but at getting them to listen carefully and be open to changing their minds.
Later, Curnow wrangled them into four self-selecting groups: the people who drive decision-making, those who strive to understand, those who can tell stories to win others to the cause, and those who keep everyone together.
Effective groups need all four, she suggested, and it helps if everyone understands this. It felt like a moment of real awareness for the participants.
On the second Saturday, the group heard from users of the park, including the golf club, the gymnastics and basketball groups, the stadium manager and the council's lead engineer on the project.
The golf club were not happy about giving up their 18-hole course but seemed to accept the option of a nine-hole or 12-hole short course.
They also surprised everyone with their answer to the question: if you had to choose between a short course and a driving range, which would it be?
Driving range, they said.
A proposal from the Golf Warehouse, to pay for a new driving range, short course and stadium, was not considered.
Curnow told me that if the local board decides to support golf in some form, first right of refusal will go to the Takapuna Golf Club. If they don't want it, the process will be opened up and Golf Warehouse will be free to pitch.
As for the stadium, it was clear it needs to be on higher ground. As it happens, the creation of a wetland will involve digging that produces a large quantity of soil. The council doesn't want to truck the soil offsite, so some of it can be used to create a raised platform for a new stadium.
It didn't take long for the group to recognise the value of this, especially as the trust that runs the stadium, not the council, will raise the money to pay for it.
In the afternoon, they began to consider their options and produce a first draft of recommendations. They split into small groups, then returned to plenary session. This happened several times, each time with the group divided afresh.
Many other potential uses of the park were tabled, including playgrounds, walking and cycling paths, picnic areas, a community garden, a skatepark, a Māori cultural/historical area, a confidence course, public art, a fitness circuit, therapeutic gardens, native bush ...
People like the idea of "versatile spaces", although a suggestion to combine archery and the golf driving range may not have been entirely serious.
On the third day, charts with ideas from the second day were pinned around the room and Curnow asked each participant to rate them all on a five-point scale: love it, like it, live with it, lament it and loathe it.
More small groups, more hard talking, and then it was time to say yes or no.
Curnow asked everyone to stand. Should there be green spaces for public use? Those who could live with this, or liked or loved it, were asked to sit. Thirty-nine people sat down.
The one dissenter explained that after "many, many sleepless nights", she wanted to keep the whole golf course.
Using the same process, a rebuilt stadium, the principles of full accessibility and multi-use areas also gained supermajority support.
And golf? Should there be a golf driving range and a nine-hole or 12-hole course? This time, 31 people sat down. That wasn't a supermajority, which required 32 votes.
Curnow suggested a rewording, to approve golf being "retained in some way, along with other activities".
A man asked for a secret ballot. "No," Curnow said. "This is the point of deliberation, that we do it together."
They voted again. This time it was 34:6, a supermajority, with the six against split evenly between those who wanted no golf and those who wanted all golf.
The group had its recommendations - and these will now be considered by the local board.
There was a good feeling in the room. They'd learned about the park, flooding, council processes, their communities and civic values. They'd sparked their own imaginations and had their say.
The process affirmed the dignity of the participants. When this happens, you suddenly realise how rare it is. And they learned about making good decisions in a group.
You could televise this process. The council could use it to address Plan Change 120 and its new density proposals. What to do with Queen St. The city's transport priorities. The emergency department crisis in hospitals.
Mind you, a couple of the guys came up with a plan they didn't put to a vote. Build a Colosseum!
Gladiators and chariot races. It's serious stuff, this deliberative democracy, but it's also fun.