Win at Question Time, and the prevailing political wind shifts, however briefly, to be at your back. Lose at Question Time, and you, and your entire team walk away from a long, thankless day's work wondering whether it's worth it and - if you're a party leader in a particularly sticky spot - whether you're worth your MPs' time. Among Question Time's small but loyal audience is the most powerful electorate of all: the party caucus.
For these reasons it's important to note that currently, National leader Christopher Luxon is losing at Question Time.
This is worthy of remark because he's managed to shunt his party's polling to the position where he could start pulling ahead of Labour. Recent polling from Ipsos suggests National is winning the argument on half of the top 10 issues bothering voters, with Labour ahead on just three.
This is not reflected in the House.
Luxon's current strategy is to open with a generic primary question, asking the Prime Minister whether she stands by all her statements. Hardly revolutionary, but it's a worthwhile opener that nearly every opposition leader has used (and which Act leader David Seymour uses to better effect than Luxon).
He then uses his supplementary questions like a scripted speech, each question listing something the Government should be doing better on. On Tuesday, Luxon's line of questioning went as follows: the number of children living in benefit homes, interest rates going up on a $700,000 mortgage, rents going up, fuel taxes, bracket creep, more bracket creep, Government spending, before finishing on inflation again.
This isn't prosecuting an issue (beneficiary households have very little to do with $700,000 mortgages) - it's a speech about Government incompetence in as many areas as Luxon can think of.
In isolation, the questions paint a picture of an incompetent government failing to get to grips with the rising cost of living.
The problem for Luxon is that the questions aren't in isolation, they're interspersed with long periods of the Prime Minister defending her record - and defending it quite well.
While in most instances, Question Time is an opportunity to hold the Government's feet to the fire, a skilful government will do its best to reflect some of that fire back on the Opposition, which is precisely what happened on Wednesday. Luxon pushed the Government on inflationary pressures, and then argued for tax cuts, giving Ardern the opportunity to note that tax cuts would send a wave of consumer spending into the economy, stoking the inflationary pressure for which Luxon was criticising her.
Worse still, when Luxon pressed Ardern on whether the Auckland regional fuel tax was punishing motorists, Ardern was able to shoot back, noting that while National repeatedly criticised the tax, its MPs will often show up when projects funded by the regional fuel tax are opened in or near their electorates. Transport Minister Michael Wood seized the opportunity to pipe up with a patsy supplementary question on the regional-fuel-tax-funded busway which, rather awkwardly, runs right through Luxon's electorate of Botany, and which he supported (like any local MP would).
Luxon's speech-like line of questioning is not a terrible tactic. It gives him an opportunity to grandstand on areas National is strong, and Labour is weak. But if used inflexibly or carelessly, it gives the Government the opportunity to argue the same points against the opposition. Helen Clark knew this and was said to meticulously map out responses to questions in a spider diagram, plotting out every single line of attack her opponents might go down.
Luxon targeted the right issues, but he was too inflexible to string them into a coherent attack on the Government. Indeed, as Ardern pointed out, the line of questioning very obviously lacked coherence.
The Government is not invulnerable. Act leader David Seymour riled Ardern on Wednesday, asking her to justify the current border policy by asking for figures to justify keeping the border shut when Omicron was raging through the community. Not knowing the precise figures is forgivable, but instead of addressing Seymour's question by giving a justification for keeping the border closed, Ardern effectively accused Seymour of being too cowardly to put his question on figures on notice, giving her an opportunity to find the figures and respond.
She had something of a point, but she also should have been confident enough in the border policy to mount a defence of it on principle, instead of turning round and needling Seymour - indeed, this is precisely what she did when Seymour used a supplementary question to have another crack.
Parliament has many flaws. The system of allocating questions based on party size gives the Government too much time to talk itself up, and not enough time for the opposition to hold it to account.
But on the level of an individual line of questioning, both the Government and the opposition have advantages and disadvantages, which can be evenly matched if both sides know what they're doing.
Winning is important. Voters don't tune in, but word of an opposition leader beating the Prime Minister in Question Time gets around, and makes people think about whether they might deserve a go at the top job.
National has managed to pull itself together in the past three weeks. Its MPs feel fresh and rejuvenated, and ready to face a Government they think is tired from four years dominated by crises.
Both of those things are true. But it's worth remembering that with four years of crises comes a fair bit of experience, which is very much on display when the two sides go head-to-head.
For more from Thomas Coughlan, follow the NZ Herald's politics podcast, On the Tiles. New episodes out Friday
