Who will win the Rugby World Cup?

What you need to know:

  • Star centre Robbie Henshaw has a hamstring injury that has ruled him out of Ireland's critical first Pool A encounter with Scotland, and they are also sweating on the fitness of fullback Rob Kearney.
  • But Joe Schmidt's Ireland have shown they can beat the best, with two historic wins over the All Blacks -- one on neutral territory in Chicago -- and the will want to give the departing coach a World Cup to add to his three Six Nations titles.

TOKYO

The 2019 edition of the Rugby World Cup is being hailed as the most open ever, with several teams considered serious contenders. Here are the main challengers:

Bookmakers' favourites to win an unprecedented third straight title, the mighty All Blacks tuned up for their Cup defence with a 92-7 demolition of Tonga and with three former World Rugby Players of the Year in their ranks, they remain the team to beat in Japan.

Coach Steve Hansen has challenged his players to embrace the pressure and it will take a momentous performance to prise the trophy from the likes of Beauden Barrett, Brodie Retallick and Kieran Reid.

But some chinks in the armour have emerged. They relinquished the Rugby Championship to South Africa after being held 16-16 at home, and slumped to a record defeat to the Wallabies after Scott Barrett's controversial red card.

They also lost their long-term position as the world's number one team, first to Wales and then Ireland, and head into the World Cup second in the rankings.

The Pool B clash between the All Blacks and the Springboks promises to be the crunch match of the early stages and could have a huge bearing on who emerges victorious in Yokohama on November 2.

South Africa waited 12 years between their two World Cup triumphs in 1995 and 2007 and are hoping the pattern repeats itself in 2019.

If Siya Kolisi, the first black player to captain the Springboks at a World Cup, lifts the Webb Ellis Cup, it would be an image to rival the famous picture of then skipper Francois Pienaar receiving the trophy from Nelson Mandela.

Coming off the back of their first southern hemisphere title in 10 years, the Springboks will fancy their chances and the advantage of having the All Blacks in their pool is that they cannot face them again until the final.

Coach Rassie Erasmus has been lauded for a "miraculous" turnaround in South Africa's rugby fortunes, only two years after suffering a 57-0 humiliation at the hands of arch-rivals New Zealand -- the heaviest defeat in the history of the Green and Gold.

"Rassie has taken us out of a dark space and put us in a good place," said South African rugby boss Mark Alexander. How good a place only time will tell.

Desperate to overcome the jinx of never having won a World Cup knock-out match, Ireland come into the tournament ranked top after beating Wales home and away in warm-up games.

Much rests on the shoulders of current World Player of the Year Johnny Sexton, with the 34-year-old playmaker suffering a drop in form in recent months.

And the injuries that have blighted previous campaigns -- an injury-ravaged squad lost 43-20 to Argentina in the 2015 quarter-final -- already threaten to strike again, especially in the back line.

Star centre Robbie Henshaw has a hamstring injury that has ruled him out of Ireland's critical first Pool A encounter with Scotland, and they are also sweating on the fitness of fullback Rob Kearney.

But Joe Schmidt's Ireland have shown they can beat the best, with two historic wins over the All Blacks -- one on neutral territory in Chicago -- and the will want to give the departing coach a World Cup to add to his three Six Nations titles.

Never has a host team failed to make the World Cup quarter-finals. Yet that was the humiliating fate suffered by England in 2015 and they will be desperate to make amends in Japan.

Their not-so-secret weapon? Australian coach Eddie Jones, who has extensive experience in Japan after leading the Brave Blossoms, who memorably beat the Springboks 34-32 in the 2015 World Cup's "miracle of Brighton".

This time around, England boast enviable firepower up front with number eight Billy Vunipola and lock Maro Itoje capable of making significant line breaks, and pace out wide with Jonny May and Elliot Daly.

They have twin playmakers in Owen Farrell and George Ford and come into the tournament with confidence high after destroying the Irish 57-15 at Twickenham.

But the canny Jones is taking nothing for granted. "Are we moving in the right direction? Yes. Are we ready to win the World Cup now? No," he said after the Ireland match.

The proud rugby nation will be hoping to send talismanic skipper Alun Wyn Jones and Kiwi coach Warren Gatland out on a high after a run of 11 home wins from 2017 that saw them briefly occupy the top of the world rankings.

But while Gatland has led Wales to three Grand Slams, limited success against the southern hemisphere powerhouses -- including 11 straight losses against the All Blacks -- has raised doubts about their World Cup-winning pedigree.

Injuries have also blighted Wales' preparation, with influential number eight Taulupe Faletau and in-form fly-half Gareth Anscombe not making the plane to Japan, while assistant coach Rob Howley was sent home over an alleged breach of betting regulations.