Oita - The All Blacks are leaving no stone unturned in their determination to have their twin playmaker experiment of Beauden Barrett and Richie Mo'unga make their mark on the Rugby World Cup.

'Beau'unga', as the partnership has been called, is coach Steve Hansen's answer to the rush defence employed by most teams to stifle the All Blacks attack in recent years.

They lead the team on the field, while off it they are even rooming together in the hope they will form a close bond that will help them think and act in unison.

After being partnered for the first time less than two months ago, Barrett and Mo'unga will start together for only the fifth occasion when the All Blacks play Canada in Oita on Wednesday.

Kick-off is at 12:15 SA time.

"It's only going to get better," Barrett said of the partnership, on show when the All Blacks opened their World Cup campaign with a 23-13 defeat of South Africa.

"I love playing with Rich, he's a super talent and hopefully for this team we can figure out how we get the best out of each other and do what's best for this team.

"We've got a lot more potential in us, which is what's so exciting."

Crusaders flyhalf Mo'unga is adept at straightening play and attacking the line while Barrett, the Hurricanes No 10, has a roving role from fullback to pop up wherever he senses the slightest gap.

As twin playmakers, they share the responsibility of directing the All Blacks' kicking game as a tactical weapon in the energy-sapping Japan humidity.

"When it comes down to tense games, with rush defences, big forward packs who like to go from set piece to set piece, keeping it slow, it's easy to say 'here you go, deal with this high ball and see how you want to start your attack again'," Barrett said.

Mo'unga said rooming together had helped their relationship develop and improved their understanding on the field.

"It's given us the chance to talk about things that aren't related to footy and ask how each other's family are doing and stuff like that," Mo'unga said.

"It all helps when we're on the field. It builds a special bond, it builds a friendship and we can trust each other and when we're on the field we're confident in what we're trying to do."

Captain Kieran Read said once the whistle goes, the All Blacks destiny is largely in the hands of Barrett and Mo'unga.

"Basically you make the toss, then those guys take over the game," Read said.

"I make the calls whether to kick for the corner or take a shot at goal; they're the ones driving our team, and rightly so.

"They're experienced and we want them to take that lead. So I encourage that."

Teams:

New Zealand

15 Beauden Barrett, 14 Jordie Barrett, 13 Jack Goodhue, 12 Sonny Bill Williams, 11 Rieko Ioane, 10  Richie Mo'unga, 9 TJ Perenara, 8 Kieran Read (captain), 7 Matt Todd, 6 Shannon Frizell, 5 Scott Barrett, 4 Patrick Tuipulotu, 3 Angus Ta'avao, 2 Liam Coltman, 1 Atu Moli

Substitutes: 16 Codie Taylor, 17 Ofa Tu'ungafasi, 18 Nepo Laulala, 19 Sam Whitelock, 20 Ardie Savea, 21 Brad Weber, 22 Ryan Crotty, 23 Ben Smith

Canada

15 Patrick Parfrey, 14 Jeff Hassler, 13 Conor Trainor, 12 Ciaran Hearn, 11 DTH van der Merwe, 10 Peter Nelson, 9 Gordon McRorie, 8 Tyler Ardron (captain), 7 Matt Heaton, 6 Lucas Rumball, 5 Conor Keys, 4 Evan Olmstead, 3 Cole Keith, 2 Eric Howard, 1 Djustice Sears-Duru

Substitutes: 16 Andrew Quattrin, 17 Hubert Buydens, 18 Jake Ilnicki, 19 Michael Sheppard, 20 Josh Larsen, 21 Phil Mack, 22 Taylor Paris, 23 Andrew Coe