Why are some Cabinet ministers sacked while others survive? That's the question many will be asking in light of today's Cabinet reshuffle in which the hapless Hekia Parata is spared but two other ministers receive their marching orders. As John Armstrong points out in his perceptive column, Reshuffle puts entire Cabinet on notice, the sackings of Kate Wilkinson and Phil Heatley are extraordinary - Prime Ministers don't normally axe incompetent or under-performing ministers. According to Armstrong, John Key has demonstrated his "chairman of the board" style of political management in undertaking a ruthless corporate restructure in which weak members of the team are let go. This boldness will impress many. The Herald's Tim Murphy (@tmurphyNZH) took to Twitter after the Cabinet announcement to say 'Rare to see a PM punt two non-performers from cabinet. And strip another of a responsibility. Rare and welcome'.

But it's the apparent inconsistency in the treatment of these two ministers compared to Parata that is fuelling much of the comment and analysis around Key's major announcement. Matthew Hooton suggests that Parata's survival is due to her protection by the Deputy Prime Minister: 'Hekia Parata's survival in that portfolio can only be explained that, like Dr Smith, she is a part of Deputy Prime Minister and Finance Minister Bill English's faction, with its ancient threat to behave badly if it does not get its way' - see Hooton's (paywalled) NBR column, Key's reshuffle exceeds expectations. Hooton also says that 'She is an education minister who has managed to fail politically despite having no reform agenda to speak of. Her reappointment indicates Mr Key has no intention of there being any serious education reform agenda between now and the election'.

Other explanations for Parata's survival come down to her valuable political identity. Tim Watkin has blogged the following: 'Parata is smart, photogenic and an important part of National's message that it's not just the preserve of rich white men. Indeed, it's interesting to ponder if she'd still be in the job if she was a rich white man. Being the poll-watcher that he is, I'd assume Parata still polls ok with women voters. Or, at least, his appeal with women is strong enough to take the risk. Because risk it is. Parata has her blood in the water now, is notoriously prickly and Key's assertion that she's staying because of her communication skills is, well, questionable to me'.

National-linked blogger Cameron Slater is also suspicious of the inconsistency and, like Hooton, points the finger at Bill English in his post, John Key has announced his new cabinet: 'Someone in Bill English's team had to get the axe to cover for Hekia Parata and so it was Kate. But I can't for the life of me work out Phil Heatley...is John Key saying that Phil did a worse job than Hekia?' He also says that the choice of David Carter as Speaker: 'is a Bill English inspired stitch up that shows that Bill and his bratpack mates are very much still causing grief in the formerly smoke filled rooms. The nomination of Carter, ostensibly for his large donation gathering ability rather than any talent is a sop to rehabilitate Nick Smith. Although there is some renewal bringing back Nick Smith and promoting Carter shows that Key is still beholden to Bill English, and rewards tired old faces'.

There is a consensus amongst commentators today that Key's reshuffle has been bolder than expected. Indeed, Matthew Hooton says that 'John Key has begun the year masterfully, with a cabinet reshuffle that has dramatically exceeded the low expectations he set for it'. Vernon Small agrees and awards the 'First trick of the political year to Key', saying that Key 'has made changes that will not look tepid compared with the reshuffle David Shearer will unveil soon' - see: Cabinet reshuffle surprise. One dissenting voice is Green co-leader Metiria Turei - see: Reshuffle musical chairs - who cares?.

Commentators are focusing on the usual 'winners and losers' of today's announcement. Along with Parata, the main winners are deemed to be Nick Smith, Nikki Kaye, Simon Bridges and Michael Woodhouse. Matthew Hooton says 'The big winners are Nathan Guy and Simon Bridges, taking on the heavyweight portfolios of primary industries and energy, mining and labour, respectively. In these portfolios lies New Zealand's economic future'. He also says that 'Nikki Kaye can be pleased at having leap-frogged Maurice Williamson, Jo Goodhew and Chester Burrows straight into cabinet', and 'Another English-ite, Michael Woodhouse, also takes his first step up the ladder, as the most junior minister but with the important portfolio of immigration'.

According to Pattrick Smellie, 'Perhaps the biggest winner is Simon Bridges'. And the CTU has quickly weighed in on the change of minister - see Newswire's Bridges has a tough job, CTU says.

Others have risen in the Cabinet rankings and Claire Trevett (Nick Smith returns in Cabinet reshuffle) notes that 'Defence Minister Jonathan Coleman has been promoted to the front bench, rising from 13th to Mr Carter's current ranking of 10th. Dr Smith goes into the 13th position and Amy Adams was elevated from 19th in the 20-strong Cabinet to Mr Heatley's current place of 15'.

What about losers? Obviously the biggest demotions are Wilkinson and Heatley - although David Farrar makes an attempt to say their 'departures are not sackings' and that 'Kate and Phil have performed well in their portfolios' - see: Key kept that close to his chest. Cameron Slater disagrees, and describes Wilkinson as 'inept'. He also warns that the soon-to-be ex-minister could cause trouble for the Government - see: The dangers of shafting Comrade Kate. And Hooton also says that the losers include 'reluctant Speaker David Carter' and the 'perennial unlucky Paul Hutchison, Todd McClay, Peseta Sam Lotu-Iiga and Tau Henare'.

The stripping of the 'Novopay portfolio' from Craig Foss in favour of Steven Joyce is another major announcement in which the former minister loses status, and the multi-minister Joyce becomes even more powerful - see Andrea Vance's Key talks tough on Novopay. One response on Twitter to this change was the quip by Ben Gracewood (@nzben) that 'We will be immediately implementing a new road-building plan to assist Novopay in transporting money to teachers'. Also on Twitter, Green activist 'toad' (@toad001) asked, 'How come Key didn't replace the underperforming Minister for the #GCSB?'

Housing is clearly a portfolio that National sees the need to bolster. As Armstrong says today, 'Heatley was slow to appreciate the political significance of the crisis in the increasing unaffordability of homes for larger and larger sections of the populace'. Nick Smith has been moved in, says Vernon Small, 'a recognition that affordable housing, combined with Labour's popular policy announced last year, has put the Government on the back foot. Key made it clear he wants new ideas from Smith and fast'.

Finally, for a satirical take on today's reshuffle, see Scott Yorke's blogpost, John Key's Reshuffle Analysed. He explains the downfall of Wilkinson and Heatley by the fact that 'their inability to communicate with the smoothness of someone like Hekia Parata will have counted against them'. In Yorke's version of today's announcement 'Gerry Brownlee is to lead a new Insulting Everyone He Meets Ministry, which will tie in with his existing role as Minister for Ruining Christchurch', 'Murray McCully retains Foreign Affairs and Dark Arts, while Tim Groser keeps Being Clever and Knowing It'.