AUSTRALIA
Previous World Cup best: Winners (1991, 1999)
Head coach - Michael Cheika: Now almost 12 months into the job, the 48-year-old has been credited for providing the Australian side with some stability. Cheika certainly has the necessary experience when it comes to coaching teams to trophies, having done so with Leinster in 2009 and New South Wales last year. He may have only taken charge of nine Test matches, yet there are those that believe Cheika's old-school approach to coaching has left Australia in good shape.
Key player - Stephen Moore
Australia have threats all over the pitch with the likes of Israel Folau, Michael Hooper and David Pocock, yet it is difficult to look beyond Moore as being the main man. Not only is the captain Cheika's mouthpiece on the pitch, it will be his job to ensure that he leads the pack from the front. With the Wallabies heavily reliant on the scrum, Moore and the props will be key figures.
Sports Mole says: A year ago it seemed that the Australians would be no-hopers heading into this tournament, yet credit should go Cheika for the transformation. Wins over New Zealand and South Africa in the Rugby Championship have resulted in the Wallabies coming back into conversations centring around the contenders. The pool is a tough one, but providing that they can come through that, they've shown that they are capable of beating anyone. The semi-finals should be the minimum target.
ENGLAND
Previous World Cup best: Winners (2003)
Head coach - Stuart Lancaster: It's well known that Lancaster has locked himself away with his coaching staff in the weeks leading up to this tournament to ensure that the preparations are of the highest standard possible. Yet, question marks still remain over the 45-year-old's ability to truly inspire a group of rugby players. He does deserve some credit, though. After all, he inherited a mess in the wake of the 2011 World Cup, and his spring cleaning job since then should be applauded.
Key player - George Ford
Owen Farrell was the man in the No.10 shirt at the beginning of November, but he had been dislodged by Ford by the end of the Autumn Internationals. There were those that had suggested that the Bath fly-half was too small to play international rugby, but the 22-year-old has proven in the Aviva Premiership that he makes his share of tackles. He also provides more attacking options than Farrell - something that could prove crucial the further that England advance.
Sports Mole says: As hosts, the expectation on the England players will be at a level that most have never previously experienced. To win the tournament, they will probably have to do something that has eluded them under Lancaster's management so far - beat South Africa or New Zealand. Yet, if they can come through this tough pool as winners, there is some reason for optimism. England have not lost to a European nation at Twickenham for almost four years and with Scotland likely quarter-final opponents, followed by France or Ireland in the last four, a place in the final - where anything can happen - is not out of the question.
WALES
Previous World Cup best: Third (1987)
Head coach - Warren Gatland: Now into his eighth year in the job and also contracted through until the end of the 2019 World Cup, it's clear that the New Zealander is a popular figure in Wales. It's easy to see why that is the case when you consider that of the last eight Six Nations, the Welsh have triumphed three times - the joint most with Ireland. Not only that, they finished fourth four years ago with a string of impressive displays.
Key player - Sam Warburton
The sending-off that brought a premature end to Warburton's participation four years ago is bound to have provided the skipper with some extra incentive. Not only is the 26-year-old his country's captain, he is one of the best scavengers of the breakdown ball in the game. It's that ability that makes Warburton Wales's central figure, regardless of which tactics Gatland deploys.
Sports Mole says: Can the defence continue to hold out so defiantly? That's the big question hanging over Wales heading into the tournament. If it does, they have a chance of upsetting either the hosts or Australia to qualify for the quarter-finals. Injuries, particularly the one suffered by Leigh Halfpenny, have certainly dampened the mood, but with a shrewd tactician like Gatland at the helm, it gives off the impression that anything is possible.
FIJI
Previous World Cup best: Quarter-final (1987, 1999, 2007)
Head coach - John McKee: Following stints coaching in France, Ireland and England, McKee has picked up plenty of experience. He joined Fiji initially as a general manager in 2013, but 12 months later the New Zealander took on the role of head coach. Earlier this year, under McKee's guidance, the Fijians won the World Rugby Pacific Nations Cup for the third time thanks to victories over Tonga, Japan and Samoa.
Key player - Niko Matawalu
As far as Fiji are concerned, the scrum-half sets the tempo for attacks. Equally comfortable when running with the ball as he is distributing it to a teammate, Matawalu has shown some good form recently. The Bath number nine ran in two tries during the warm-up victory over Canada. He limped off towards the end of the first half of that game, but reports have suggested that it was little more than a precaution.
Sports Mole says: It's assumed by many that the quarter-finalists from Pool A will come from two of Australia, England and Wales. But, as the latter found out at their expense in 2007, Fiji are no mugs. In terms of natural ability, there will be few better nations at the World Cup than McKee's team. But, they do have a tendency to neglect the less glamorous side of the game, which could ultimately be their downfall.
URUGUAY
Previous World Cup best: Pool stage (1999, 2003)
Head coach - Pablo Lemoine: Make no mistake about it, the 40-year-old is a man of considerable rugby pedigree from his time as a player. A career that started with a two-year stint in Bristol took him to France, where he would win two Top 16 titles with Stade Francais. The former prop also featured at the World Cups in 1999 and 2003, during which time he scored four tries. Lemoine has been in charge of Uruguay since 2012, with his finest achievement coming 12 months ago. Uruguay had not won the South America Rugby Championship in 33 years, but under his watch the drought was ended.
Key player - Felipe Berchesi
There will be few fly-halves at the World Cup that have a bigger boot on them than Berchesi. The 24-year-old played a key role in helping the Uruguayans to reach the tournament with his performance in the final qualifier against Russia. He also starred during a recent friendly outing against an Argentine XV - a game that saw him kick five penalties. Two of those were scored in the closing stages, which highlights his ability to cope under pressure.
Sports Mole says: Whatever way you dress it up, Uruguay are the big underdogs here. In their two previous appearances at a World Cup they have never advanced beyond the pool stage, and with such established nations for company this time around, it seems impossible that they will buck that trend. It's tough when you have a squad that has to balance playing rugby with their day-to-day lives. After all, captain Santiago Vilaseca is a banker by trade, while a number of players are believed to have lost their jobs for requesting too much time off to train.
Pool A fixtures
Friday, September 18
England vs. Fiji
Sunday, September 20
Wales vs. Uruguay
Wednesday, September 23
Australia vs. Fiji
Saturday, September 26
England vs. Wales
Sunday, September 27
Australia vs. Uruguay
Thursday, October 1
Wales vs. Fiji
Saturday, October 3
England vs. Australia
Tuesday, October 6
Fiji vs. Uruguay
Saturday, October 10
Australia vs. Wales
England vs. Uruguay
Prediction: 1. Australia 2. England 3. Wales 4. Fiji 5 Uruguay