Chris Robshaw (Gallo)
Cardiff - World Cup hosts England play Australia at Twickenham on Saturday in a crunch match that will go a long way to deciding who advances from the tough Pool A that also features Wales, Fiji and Uruguay.
With just two of the five teams qualifying for the quarter-finals - and only three now in a position to advance, Wales are currently on top of the "pool of death" on 13 points from three victories.
Undefeated Australia are second on 9pts and England third on 6pts, having picked up a defensive bonus point from their dramatic 28-25 defeat by the Welsh last weekend.
What scenarios, taking into account bonus points for scoring four tries or more and finishing within seven points of the winner, could play out on Saturday before next weekend's final round of matches that pitches Wales against the Wallabies and the English against minnows Uruguay.
Q: Do England need to beat Australia to stay in World Cup contention?
A: More importantly, England must not lose! A defeat by the Wallabies and the host nation's dream of a second World Cup will be over. However, a draw with England not picking up an attacking bonus point sees Wales qualify but leaves the hosts still capable of catching Australia. A draw with an attacking bonus point for England would leave all three sides still in contention come the final weekend of games.
Q: What happens if England beat Australia?
A: Should England defeat Australia, regardless of bonus points, the hosts, the Wallabies and Wales will all still be in the equation going into the final weekend. Pool A leaders Wales would require at least one bonus point to secure qualification. But England would be in pole position given their match-up against whipping-boys Uruguay, in which they would back themselves to get an attacking bonus point. Wales hooker Scott Baldwin insisted permutations were not at the forefront of Welsh planning. "It does qualify us if Australia beat England, but we want to top the group and we want to beat Australia. We are going out next week to get the win, first and foremost," he said.
Q: If Australia beat England, they qualify for the quarter-finals?
A: Yes, the simplest route would be for an Australian victory at Twickenham on Saturday. That would mean Michael Cheika's Wallabies advance into the quarter-finals along with Warren Gatland's Wales at the expense of England. The encounter between Australia and Wales at Twickenham on October 10 would decide who tops the pool and who finishes runner-up. Even if England were to claim two bonus points in defeat by Australia, they would only finish with 13 points which, at best, would equal Wales or Australia, both of whom would progress having recorded head-to-head victories over Stuart Lancaster's team.
Q: Regardless of Saturday's outcome, will Wales qualify if they beat Australia in the final round of pool games?
A: Yes, undefeated in four pool games, the Welsh would top the group and qualify as winners should they buck a 10-match losing streak against the Wallabies.
Q: What's in it for the pool winner and runner-up?
A: The winner of Pool A will play the runner-up of Pool B, and vice versa. Japan's shock win over South Africa blew Pool B open, although the Springboks seem to have recovered their nerve and are favourites to top the pool. Current pool leaders Scotland play South Africa and Japan take on Samoa this weekend in two games that will help decide who qualifies. Realistically, Australia, England and Wales would be the first to admit they'd prefer not to face two-time champions South Africa.
Q: What do the bookies say?
A: Well, Australia remain second favourites, at 13/2, behind champions New Zealand to win the World Cup. England are third favourites at 7/1. But, interestingly, betting odds on the two teams advancing from Pool A favour Wales with Australia hedged with England.