The versatility of the likes of John Bateman, Viliame Kikau, David Fifita and Kodi Nikorima will make them among the most valuable players at October's World Cup Nines.

The biggest decision for coaches of the 12 men's and four women's teams competing in the tournament at Bankwest Stadium will be which four positions to forego from the traditional 13-a-side game.

The Adrian Lam-coached Australian team which won last year's Commonwealth Championships at Redcliffe played with a left and right edge player – known in touch football as "links" – and wingers who rotated to fullback when needed.

In contrast, St George Illawarra WNRL coach Daniel Lacey opted to play with just one middle forward, a dummy half and full backline when he had charge of the club's successful Under 18s team in the first season of the Tarsha Gale Cup, which began in 2017 under a Nines format.

"You've only got nine minutes each way so you don't need a lot of go-forward, the spaces are out wide so you need people who can go to outside shoulders to create the overlaps and can shift laterally in defence," Lacey said.

World Cup 9s launch

Mobile forwards who can make metres on an early carry and ball play will be more suited to the middle roles, with the likes of Manly's Jake Trbojevic, North Queensland's Jason Taumalolo, Brisbane's Payne Haas and Rabbitohs pair Sam Burgess and Cameron Murray set to be key players for their countries.

Out wide, there is not enough room to carry a second-rower and a centre so players with the attributes to play both positions will be in favour, such as Bateman (Raiders), Kikau (Panthers), Fifita, Kotoni Staggs (both Broncos), Latrell Mitchell (Roosters) and Jack Wighton (Raiders).

Depending on how many middle forwards are used, wing and fullback could also be a combined role as all players need to defend in the line but one will have to drop back for a kick on the last tackle.

Warriors captain Roger Tuivasa-Sheck, Sea Eagles fullback Tom Trbojevic, Roosters star James Tedesco, Canterbury's Dallin Watene-Zelezniak and Brisbane's Jamayne Isaako are ideally suited to those roles.

Another option is to play with a fullback who can double up in a playmaking role, such as St George Illawarra's Gareth Widdop, Newcastle's Kalyn Ponga, Melbourne's Cameron Munster, Brisbane fullback Anthony Milford or Sharks five-eighth Shaun Johnson.

Dummy-halfs and first receivers direct the attack and also need to be interchangeable, highlighting the value of Nikorima and St George Illawarra halfback Ben Hunt as both have played hooker at representative level.

Manly duo Manase Fainu and Api Koroisau are hookers who can also play in the halves for Tonga and Fiji respectively.

Given the importance of those roles, the likes of Sea Eagles halfback Daly Cherry-Evans (Australia), Raiders hooker Josh Hodgson (England) and South Sydney's Damien Cook (Australia) will still be among the first players picked for their countries.

"You still need a rugby league approach to the normal part of our game, even though there are only nine players on the field," Kangaroos assistant coach Michael Hagan said.

"It is a little bit more strategy, a little bit more space to cover and combinations are probably important as well.

"You need guys who can adapt and manage things on the run, guys who can play with some structure but can also play what they see and take advantage of time and space."

Hagan worked with Lam, who is also on Meninga's coaching staff, at the Commonwealth Championships, which were held at Redcliffe in the lead-up to last year's Commonwealth Games.

You need guys who can adapt and manage things on the run Michael Hagan on the challenge of Nines football

Among the players in that Australian team were Fifita, Staggs, Wests Tigers centre Paul Momirovski, Rabbitohs fullback Corey Allan and North Queensland's Scott Drinkwater.

Defensively, teams are likely to use one marker and have eight players in the defensive line.

However, if more than two players need to commit to a tackle the opposition will have an overlap.

Fullbacks have little option other than to drop back on the last tackle for a kick but in doing so they invite the attacking team to run the ball.

"Second-phase is absolutely lethal so guys like Taumalolo and Andrew Fifita who can ball play are valuable," Lacey said.

"People who can swing [from side to side] too are really good. If you watch Tedesco run around the back of the ruck and track from the short side to the long side real quick, not many players can do that. He is in the right spot, he identifies the ruck and is counting the numbers.

"Sammy Bremner was really good at it. That was her bread-and-butter, to be able to move from behind the ruck, choose a side and get there in time.

"In Nines, you have got a lot more field to cover and a lot of inside pressure, then you move it again and defences have to go from one side to the other."

The role of the interchange will also be important as players get fatigued quickly from the speed of the game and it is likely that teams will carry a middle forward, a playmaker and left and right edge players on the bench.

Australian coach Mal Meninga is expected to use the Downer World Cup Nines to give younger players such as Wighton, Murray and Fifita a taste of international football.

Players whose clubs aren't involved in the NRL finals, like Hunt and Dragons team-mate Tyson Frizell, are likely to play at the Nines ahead of the Oceania Cup Tests against New Zealand in Wollongong on October 25 and Tonga at Eden Park on November 2.

Tickets for the Downer World Cup Nines are available at nrl.com/tickets