IT wasn’t their best result, but the Scottish Greens will still be very happy with Thursday’s tally.

At their 2003 high point, they won seven list seats on 6.9 per cent of the vote. On Thursday it was six on 6.6 per cent.

But at the elections in-between the Greens had a mere two MSPs, and the party was dreading that, once again, a late squeeze would bring disappointment.

Now, the Greens not only have triple their recent numbers, because of the SNP’s missed majority, they also have potentially unprecedented leverage.

As the only other Holyrood party for Yes, it will be hard for the SNP to bypass them and horse trade by choice with Unionists in order to pass budgets and new laws.

It’s the moment the Greens have been waiting for. The more progressive tax system and fracking ban they want are now a lot closer.

Patrick Harvie’s party traces its result to the referendum - effectively a rolling two-year advert for Green ideas in front of a fresh audience.

Harvie established himself as one of the best debaters for Yes, his thoughtful responses and desire for change on the monarchy, tax and the oil industry in sharp contrast to Alex Salmond’s ringmaster style and a pitch that stressed continuity rather than radicalism.

“We really got our game on in the referendum,” said one Green. “It was the first time a lot of people got involved in politics and they were hearing our ideas. It was a big confidence boost.”

Green membership shot up after the No result, from 1700 to around 9000, a bigger percentage rise than even the SNP enjoyed, bringing record funds and personnel.

To drill their new recruits, the party dived into the general election, standing in 31 of 59 seats, using it as a ‘live fire exercise’ before the main Holyrood battle.

Because the Greens picked their 2016 list candidates early in 2015, they could also use last May to introduce them to voters a year in advance, building their profile and gathering momentum.

By September, the party had written its internal election strategy, followed by a manifesto sign-off around Christmas.

The headline pitch, as in the referendum, was that the Greens offered radicalism at Holyrood.

This crystallised into the slogan “A bolder parliament for a better Scotland” in the New Year.

The Greens also professionalised. At the general election, they had one paid staffer.

For Holyrood, they had around 15, including an organiser in each electoral region, an expanded press office, and the marketing guru Ian Dommett as campaign brand adviser.

Dommett previously devised the SNP's winning “It’s Time” campaign in 2007.

An early decision to push for parity in TV debates also paid off, with a successful lobbying operation of the BBC and regulator Ofcom securing Harvie equal airtime with other leaders.

The BBC had initially suggested classing the Greens as a “smaller party” alongside Ukip.

According to the Greens, their campaign was also leant a hand by the SNP.

On top of the government’s refusal to ban fracking, Nicola Sturgeon's status quo on income tax boosted the Greens’ call for a “bolder parliament”. Even “Both Votes SNP” had an apparent upside.

One Green canvasser said they had been “shocked” at how many people didn’t appreciate they had a second vote. But when the news sunk in, those same people liked the idea of splitting their constituency and list votes and giving the Greens the latter, the source said.

Harvie also upped the party’s profile by standing in the Glasgow Kelvin seat, while Johnstone and John Wilson stood in Edinburgh Central and Coatbridge & Chryston, indicating the Scottish Greens were stepping up a gear.

Harvie came a respectable second to the SNP, Wilson just held his deposit, but Johnstone, though fourth, may well have helped Tory leader Ruth Davidson take the seat from the SNP.

It wasn’t all plain sailing, of course. The Greens suffered a bout of bitter infighting over who should be Harvie’s fellow co-convener. He and MSP Alison Johnstone wanted Zara Kitson, but activists installed her rival, the North East list candidate Maggie Chapman. Chapman’s failure to get into Holyrood means internal party dynamics should be smoother than if she had.

Sarah Beattie-Smith, co-convener of the Greens’ elections & campaigns committee, credited hard work by a hugely expanded membership for the result, but also SNP failure to “use the powers we all fought bloody hard for”.

She said: “Lots of people felt the same way. They thought of the SNP as inheritors of the Yes movement and they were looking for something that had the enthusiasm of that movement.

“It’s been a really interesting journey watching people feel disillusioned with the SNP playing safe, taking them for granted and Labour in disarray, and deciding to vote Green.”