The contest to become Prime Minister and Deputy Prime Minister is starting to look like an elaborate wiring diagram.
With two confirmed contenders for deputy, Paula Bennett and Simon Bridges, and one possible, Amy Adams, just who could work with whom becomes complicated.
Bennett and Bridges have offered themselves as a deputy to the likely next leader, Deputy Prime Minister Bill English.
Bennett delayed her confirmation and suggested she was thinking about going for the top job.
Adams is more often paired with another contender, Health Minister Jonathan Coleman. She has not confirmed she would stand as a deputy, nor has she ruled it out.
Like the others, they are thrilled to have their names mentioned in any speculation about leadership, no matter their chances.
It puts them in the frame for the next leadership contest, which could happen in less than a year if National does not win a fourth term at the 2017 election.
Coleman and the third leadership contender, Corrections Minister Judith Collins, are similarly guaranteed a place in the next contest no matter what their chances are in this race.
From the outset, Bennett has been the favourite to be English's deputy on the invisible ticket, which includes Steven Joyce as Finance Minister.
It is invisible because it upsets the caucus to think these matters are pre-determined.
The new leader's preference for deputy is relevant to the outcome but not necessarily the overriding factor.
The selection of a political deputy is dictated by factors that vary from contest to contest and party to party.
English's own election as deputy to John Key in 2006 was part of a political deal to stop English joining the contest and to satisfy his caucus supporters, led by Simon Power and Katherine Rich.
They demanded better treatment of him than had been delivered by Don Brash in the previous leadership contest.
Gerry Brownlee was the deputy leader when Brash resigned - although Brash conducted a mad experiment by initially nominating Nick Smith, English's numbers man, as his deputy.
Brownlee earned huge kudos from his colleagues in 2006 for stepping aside for the Key-English pact that served the party well for the next 10 years.
Helen Clark appointed Michael Cullen as deputy, again a highly successful team, because he had led a serious move to get rid of her.
If English is elected with a huge mandate and no bitterness, he would be expected to choose his deputy, almost certainly Bennett, and have the caucus endorse his choice.
Bennett complements English in terms of gender, geography, ethnicity and personality.
But if a solid rump of support for Coleman or Collins emerges, and one that promises not to lose quietly, it may have to be negotiated.
But the fact that no one has publicly declared for either of them suggests it won't come to that.