FIJI
Best: The semifinals. England can be beaten, Wales are vulnerable. The problem is a dreadful record against Australia. If Fiji live the dream, a tantalising quarterfinal against Samoa or Scotland awaits. Nemani Nadolo could be a tournament star.
Worst: A solitary win in the the Pool of Death, a real possibility. Playing the Wallabies after a draining opener at Twickenham could send Fiji on a downward spiral.
URUGUAY
Best: One good performance...but even that is unlikely for an amateur side in this company. In truth, there isn't a best case scenario.
Worst: They get beaten up in every game (they were slaughtered by the heavyweights in their last World Cup appearance in 2003).
- Chris Rattue
POOL B
SOUTH AFRICA
Best: Winners. They have a promising path. The Springboks should top their pool while getting two half-decent workouts, then could face a psychically-stretched Australian side battered by their Pool A exertions.
Worst: Dip out in the quarterfinals. Australia have the knack against South Africa, including the controversial, David Pocock-inspired victory in the 2011 quarterfinal at Wellington. Playing England at Twickenham would be a hard-to-pick battle of behemoths and goalkickers.
SAMOA
Best: Making the quarterifnals. Very achievable, but England and Australia would almost certainly be too good for them. Should Wales or Fiji progress though, different story.
Worst: Samoa carry a mighty World Cup reputation but this year's squad lacks a certain x-factor and there is less chance these days of catching one of the top dogs unaware.
SCOTLAND
Best: Despite an awful 2015 record, the addition of John Hardie is important and this is an inviting pool. The quarterfinals call - all roads lead to the showdown with Samoa in Newcastle which could be one of the contests of the tournament.
Worst: But it's a dead end after that.
JAPAN
Best: Remember 2011, when Japan actually threatened to beat France at North Harbour. They can give Scotland a bit of bother this time.
Worst: Japan as a major rugby centre has been revealed as a sham by the Super Shenanigans. It doesn't feel like their year. They will be destroyed by South Africa and Samoa.
USA
Best: Beating Japan, the other alleged new territory (yet again) for world rugby.
Worst: Losing every game, but...the USA ended a 16 year winless World Cup streak against Japan in Gosford, 2003. Their previous win was against...Japan.
- Chris Rattue
POOL C
NEW ZEALAND
Best: Back-to-back World Cup winners, trouncing either England or Australia in a one-sided final.
Worst: Quarterfinal. Cardiff. France.
ARGENTINA
Best: Put in a strong performance against the All Blacks, finish second in pool, get a quarter-final matchup against an erratic France before falling in the semifinals.
Worst: Falling at the hands of an under-the-radar Tongan side, and becoming the biggest group stage casualty of the Cup.
TONGA
Best: The Tongans beat France in 2011 and Samoa in 2007, while also coming within five points of toppling South Africa in 2007. Beating Argentina is a possibility, but they'll have to make sure they don't slip up at the hands of Georgia.
Worst: Slipping up at the hands of Georgia.
GEORGIA
Best: Don't underestimate Georgia's defence. They only lost by four to Ireland in 2007, and conceded just 15 to Scotland and 25 to Argentina in 2011. Could defeat Tonga and keep it close against the Argies.
Worst: Fourth place in the group, score less tries than their output in 2011 (3).
NAMIBIA
Best: Hold the All Blacks to under three digits. Break their record for average points scored per game (14).
Worst: Their record extends to 19 World Cup games, 19 World Cup losses.
- Niall Anderson
Pool D
FRANCE
Best: Finalists. Two upsets is possible, but the final could prove a step too far once again.
Worst: The "France always show up at World Cups" narrative proves to be nothing more than coincidence and they flame out early in the piece.
IRELAND
Best: Winners - but only if another nation takes out the All Blacks.
Worst: Everyone realises the gulf in class is still there when Nathan White and Jared Payne take on the All Blacks in the quarterfinal.
ITALY
Best: Make their first ever Rugby World Cup quarterfinals appearance by beating either France (have won two of their last five contests) or Ireland (Beat them in 2013).
Worst: Lose to Kieran Crowley's Canada and go home wondering when Italian rugby will ever make a statement.
CANADA
Best: Re-live their quarterfinal clash against the All Blacks in 1991. By playing it on the big screen in the hotel lobby.
Worst: Continue their losing record against Romania, and go winless for just the second time in their World Cup history.
ROMANIA
Best: Avenge their much-remembered 34-3 loss to Canada at the 1995 World Cup.
Worst: Going winless for the second straight World Cup is a distinct possibility.
- Niall Anderson