Williams backs hosts for last eight
Former Wales star Martyn Williams believes that the 2015 World Cup's so-called pool of death will be decided on points difference - but he has backed England to secure a quarter-final place.
Hosts England, twice-world champions Australia and Wales, who have won two Six Nations titles since they reached the World Cup semi-finals four years ago, will contest two knockout places available from a pool that also includes Fiji and Uruguay.
At least one high-profile group stage casualty is guaranteed, although any edge probably lies with England, given that they tackle Australia and Wales at Twickenham.
"For me, it is the flick of a coin," Williams told Press Association Sport.
"There is nothing between the three sides on their day.
"You would have to say that with England being at home, I can't see them losing two pool games at Twickenham. I can't see both Australia and Wales beating them there.
"England could lose one, but they are not going to lose two games. I think the group will go down to points difference, and I think the key game for everyone is going to be when they play Fiji.
"England, Wales and Australia will all probably beat each other, and it could be about which team can really put Fiji to bed and gets some points against them."
England and Australia both start their World Cup campaigns in September against Fiji, while Wales face a Millennium Stadium appointment with 5,000-1 tournament no-hopers Uruguay on the opening weekend before tackling England six days later.
"There is no pressure on Fiji in that opening game of the tournament against England," added ex-flanker Williams, who won 100 caps for Wales and played in three World Cups during his Test career.
"They can just turn up and just play well, and they will cause teams problems.
"Wales have got a nice little start with Uruguay, to get that one under the belt, but whatever happens it is going to go down to the last game between Wales and Australia (on October 10).
"I think whoever wins that last game will go through, as well as England. I think England will go through, and I think it will be between us and the Aussies in that last game.
"Traditionally, northern hemisphere teams do well when the World Cup is staged in the northern hemisphere - England in 1991 and 2007, and France in 1999 - reached finals, so you would perhaps expect a northern hemisphere team in the final.
"But at the moment, I can't look past New Zealand (as winners).
"The All Blacks have ridiculous strength in depth. But who knows? England, Wales, Ireland and even France are capable of getting to the final."
With more than two months to go before the tournament starts - World Cup preparations include a Rugby Championship in the southern hemisphere, plus numerous worldwide warm-up Tests - Williams accepts that injuries could be a factor.
Wales have already lost powerful British and Irish Lions centre Jonathan Davies from their plans, while his fellow back Liam Williams is currently sidelined due to a foot problem and prop Samson Lee is recovering after suffering a serious Achilles injury during last season's Six Nations.
"As we've seen, injuries are going to be huge, which could some through for Australia in their Rugby Championship games and Wales and England in the pre-World Cup matches," Williams said.
"We can't lose any more key players. Jon (Davies) is a big loss, make no bones about that. We need to have the likes of Taulupe (Faletau) and Alun-Wyn (Jones), those boys, fit throughout the tournament."
Wales head coach Warren Gatland is due to name his final World Cup squad on August 31, and Williams said: "It will be interesting to see what happens in the warm-up games.
"I was involved in those games four years ago, and it changed really. You could see guys like Taulupe and Sam (Warburton) coming through, and after they had beaten England at home, they realised how good they were.
"You could feel the impact of the younger players in the camp, and even though the tournament is so close, there is a lot that can happen between now and then."