New Zealand First leader Winston Peters is fond of Kenny Rogers' advice in The Gambler: "You've got to know when to hold 'em, when to fold 'em, know when to walk away and know when to run."
National Party leader Simon Bridges is around the poker table and hascalculated that Winston Peters is bluffing about his hand - and so he is holding.
Bridges' unequivocal decision to rule out any deal with NZ First after the election is a gamble.
Bridges has worked out he has more to lose from keeping Peters on National's radar than he does from ruling him out.
Bridges is betting Peters would always have sided with Labour if he was the kingmaker in 2020 anyway. In all likelihood, the bulk of National Party voters too will have worked that out themselves.
But there will also be a few who might think they are being clever and vote strategically for NZ First. Bridges is betting the election will come down to a very narrow margin.
He wants every single vote he can get - and that means spelling it out to National Party voters that there is absolutely no hope of a National-NZ First Government.
It is a big risk because in the event Peters is again the kingmaker, people will conveniently forget they thought he was always going to go with Labour anyway.
Bridges will cop the flak for National not getting a chance. But if Peters is out of Parliament altogether, Bridges will be praised for his canny decision.
And that is Bridges' overall plan - cutting off enough voters so NZ First falls short of the 5 per cent threshold to get back in.
Hence the reason he cited for the decision was a lack of trust in NZ First. The specific reason was the court case against National MPs while he was negotiating with them.
Trust was the same reason former PM John Key cited in 2008 and 2011. Bridges is hoping for the same result as 2008, when NZ First ended up out of Parliament.
Peters inevitably decried Bridges' decision, saying that if Bridges wouldn't pick up the phone somebody else in National would.