Ian Foster's 'simple' theory for the All Blacks' World Cup squad

All Blacks head coach Ian Foster has offered his thoughts on Rugby World Cup squads which are set to expand to 33 from 31 players for this year's tournament in France.

The expanded squad size increases the odds of a bolter selection and also reduces the chances of a big name omission.

The All Blacks from 2011 and 2015 had notable omissions from both squads, with Ben Smith, Sitiveni Sivivatu, Liam Messam, and Wyatt Crockett all missing out on the first of back-to-back World Cup wins.

Key contributors from the 2011 World Cup-winning team Aaron Cruden, Cory Jane and Israel Dagg all missed the cut in 2015, along with Lima Sopoaga and Charles Piutau.

In 2019 Owen Franks was a big omission, along with barnstorming midfielder Ngani Laumape.

Foster shared some logic as to how the All Blacks may use the 33 selections later this year.

"I forget what 2015 was, I know 2019 was one more and know we've got one more again [in 2023]," Foster told Jason Pine's Newstalk ZB show.

"If you look at it with simplicity, you've got two lots of 15, two teams, and then three extras.

"Potentially a third hooker, a third No 9, and a third 10, some of your specialist positions.

"That's the simplicity of the logic."

In 2019 with just 31 selections the All Blacks took three hookers, three halfbacks and two first fives to Japan for the World Cup, skimping on other positions like blindside flanker where they did not take a specialist.

This time around they will have the luxury of not having to cut back in other position groups to bolster the spine positions.

Hurricanes halfback Cam Roigard has been a popular selection as a World Cup bolter candidate with regular starter and All Black TJ Perenara recovering from his Achilles injury.

The other halfback stocks include Aaron Smith, Folau Fakatava, Finlay Christie and Brad Weber for a total of six options including Roigard for Foster's staff.

At hooker the All Blacks have Samisoni Taukei'aho, Codie Taylor and Dane Coles while the in-form Asafo Aumua is potentially in line to earn an All Black recall.

The first five positional group has Beauden Barrett and Richie Mo'unga, assumed to be guaranteed picks if healthy, with Damian McKenzie and Stephen Perofeta fighting it out to be the third option, although whoever misses out might also be selected as fullback cover.

Foster highlighted the versatility in the backline as a key strength which will enable the selectors to maneuverer the squad in other areas.

"But we've got a lot of versatility in our group, particularly the backs," he explained.

"And quite a bit of versatility in our locks and loose forward types.

"We're having some good debates about the make-up of our group already.

"We've got the Rugby Championship where we will be picking 36 to keep the door open for people as well.

"The lion's share of our group is pretty clear but we want to keep an open mind right to the very end.

"We've got an opportunity in the Rugby Championship and we've also got a New Zealand A team playing two games against Japan to trial a couple things."

On whether there would be a World Cup bolter such as Cam Roigard or Shaun Stevenson, who have been the in-form players in Super Rugby Pacific, Foster remained coy on the subject.

"I don't know, it wouldn't be a bolter if I told you, would it?" he joked.

"It is one of those questions I'm not allowed to answer, the way you've framed it. Who knows?

"If you look at the bigger picture, we've already scratched... you look at Sevu Reece's injury, George Bower's injury.

"Part of this year is looking at all the contingency plans, making sure we've got our depth options very clear.

"Due to the size of squads we've had in recent years, with travel and Covid, the odds of having someone who hasn't played for us already aren't that great, but you never know.

"Let's just keep excited about it a little bit longer."