If Labour had lost Mt Roskill to National, the National-led Government would have been strengthened to the extent that it would have been able to push through major reforms of the Resource Management Act which the Greens opposed.
The Northcote contest is not as politically charged. Whatever the result, it will not change the coalition Government's ability to pass laws because the three coalition parties have 63 votes.
That means a strategic deal – stepping aside to help Labour win – is not as important for the Greens on this occasion.
The main consideration by the party's executive is likely to be money.
The party's finances are in bad shape following an election campaign in which it had to re-do or scrap many of its billboards after its co-leader Metiria Turei resigned.
It has shrunk from 14 MPs to eight, cutting the amount of tithing it gets from its MPs – a major source of its revenue.
But there are a few factors which could encourage the Greens to stand a candidate.
The party is still hovering just above the 5 per cent threshold in polls, meaning that the next two and half years will be a fight for its survival.
That means taking every opportunity to set itself apart from Labour and promote Green values.
The byelection is taking place at a time when the membership is uneasy about recent decisions made by the caucus.
Some members are deeply upset about the Greens' decision to hand over their questions from Question Time to the National Party. Long-time members are also disappointed at the Greens' initial support for the "waka-jumping" bill, which will prevent MPs from staying in Parliament if they quit their party.
A no-show in the byelection could be seen as another missed opportunity for the Greens to promote their brand independently from Labour.
Its candidate in the 2017 election was Rebekah Jaung, a Korean-born doctor. She is rated by the party, in particular because she represents the modern, diverse face of the Greens.
She is the most likely candidate if the Greens decide to stand in the byelection. No other person has expressed a serious interest.
But if the party cannot gather the money or volunteers to back her, it is likely to dip out.
In the end, a poorly run or low profile campaign could be more damaging than not standing at all.