Henry: The best Rugby World Cup team we've had

New Zealand All Blacks Daniel Carter and second-five Sonny Bill Williams during at the Adidas Force of Black fan promotion event, held at Southbank, London. Photo / Brett Phibbs.

The 2015 All Blacks are better than Sir Graham Henry's World Cup-winning side - says the man himself.

As the All Blacks winged their way to the UK on Friday to prepare for the tournament's kick-off next weekend, Sir Graham spoke of the All Blacks' chances of becoming the first team to win back-to-back tournaments.

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Sir Graham said this year's side was not only better than his triumphant 2011 team, but he believes they're probably the best unit to pull on the black jersey.

Yet still, Sir Graham has warned the nation that nothing can be taken for granted in the UK over the next seven weeks.

"We're in good shape. The All Blacks are always in good shape. I think they're probably the best team we've ever had," he said.

"But there's no guarantees of winning, as we've found previously.

"It will be a very competitive World Cup, but we can't do anything more than we've done so we're in good shape to perform well."

Although the All Blacks' pool games, beginning with Argentina next Monday morning (NZT) then Namibia, Georgia and Tonga, pave an easy passage into the knockout phase, New Zealand are likely to face either Ireland or France in the quarterfinals stage at Cardiff's Millennium Stadium.

It was against the latter team, and at the same venue, that the Sir Graham-coached team lost in the 2007 quarterfinals.

"It could be France in the quarterfinal at Millennium Stadium in Cardiff, again. It's sudden-death, a final in itself," he said.

"You've just got to keep on winning. That makes the tournament unique and we've had that experience with France in the past, at Millennium Stadium.

"They've just got to concentrate on performing at the time."

Sir Graham and his wife Lady Raewyn will be in the UK during the Cup.

The former coach has signed on to be an official tour guide.

The pair will then have a post-tournament holiday in Europe.

The World Cup-winning coach's belief that the All Blacks can retain the Webb Ellis Cup has been backed by the release of a major statistical analysis of the 20 tournament contenders.

Leading UK-based statistician Niven Winchester yesterday released his picks for the Cup on the statslife.org.uk website, based on world rankings and past results.

Winchester says the All Blacks have a 47.1 per cent chance of being crowned champions in the November 1 final. The next-best team was England, at 21.8 per cent.

Winchester is also predicting an All Blacks versus England final.

According to the numbers guru, fans of the Wallabies shouldn't be preparing any post-final victory parties, rating them just an 8 per cent chance of winning the tournament.