We're now only days away from the Rugby World Cup kicking off, and millions of supporters from around the world will tune in to see who will be crowned 2015 world champions.

The tournament is the pinnacle of world rugby, in which four years of hard work and dedication come together for a six-week tournament. And looking at the teams that will be taking part, there is no question that rugby union is a world game. Each nation has its own unique style of play, however, but this keen spectator is hoping to see plenty of exciting, expansive running rugby with brutal defence.

Shannon Parry is an Australian Sevens player and captain of the Australian team that competed at the 2014 Women's Rugby World Cup © Getty Images

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As I cast my eyes across the pools of World Cup contenders, I can't go past the defending champions, New Zealand. The All Blacks have proven to be the dominating nation of rugby union for a number of years and they are the form team leading into this World Cup.

The other teams to have legitimate claims are the other traditional rugby powerhouses such as Australia - currently ranked No.2 in the world - and host nation England, who will be desperate to perform in front of their own people. You also have to think South Africa, France and Ireland will also be in contention towards the pointy end of the tournament, and there's little doubt the race for the William Webb Ellis trophy will be hotly contested.

I also wouldn't write off Samoa, Tonga and Fiji from causing a shock or two, as they continue to improve and can cause headaches with their ad-lib style of play. The Pacific nations now also have players playing regularly in various European competitions, which helps them dramatically.

Most of all, as a flanker myself, I'm looking forward to seeing the contest at the breakdown; I can't wait to see the likes of Richie McCaw, David Pocock, Sam Warburton and Thierry Dusautoir causing havoc at ruck and maul. They are each recognised among the best individual players in their teams, and they are leaders in their own ways with or without the armband; they are sure to lead their teams from the front into battle.

Shannon Parry is excited to see New Zealand's Richie McCaw plat at the Rugby World Cup © Getty Images

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The modern game with defensive structures so established means turnover ball is the best ball you can get on the field, and these four players are key as they turn over more ball for their respective teams than any other players; they are real jackals. Turnover ball in the modern game allows a team to fracture defensive lines and attacking play to dominate. Hence players such as McCaw and Pocock create attacking opportunities, and we all know by now the team that controls the ball and capitalises on opportunities goes a long way to winning.

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In my opinion, flanker is one of the hardest and most physically demanding positions on the rugby field as your body is continually in contact with the opposition. The four players above are among the hardest-working players on the field, and what they put their bodies through is mind boggling. They consistently play the full 80 minutes, put their bodies on the front line, make bone-rattling tackles, and are among the first in support and at the breakdown. These players are continually in the thick of the action and have proven over many years to be game changers for their respective nations. They are incredible athletes who thrive on doing the hard work for their team mates, and their teams are unlikely to go deep in the knockout stages of the tournament with a substantial impact from their star flankers.

I am also definitely eager to see Sam Burgess play for England just 12 months after winning Australia's National Rugby League grand final with South Sydney Rabbitohs. Known as a very strong runner and defensive player in rugby league, he has shown glimpses of this for Bath and it will be interesting to see if he can take it to the next level for England and become an integral part of their team. He's been selected as a centre, but I note that Bath now see him as a flanker.

Jean de Villiers, another centre, is a key element of the Springbok back line and it will be interesting to see if he is back to his best after his lay-off due to a knee injury. Along with De Villiers, the lineout master Victor Matfield will be an integral part of the South African challenge with his experience and sheer physical presence leading the way in the forward pack.

Daniel Carter and Jonathan Sexton will be pivotal among the fly-halves, and I expect them to show their expertise by marshalling their teams around the field and ensuring solid field position. These two players have been in good form throughout the club and international seasons, but they will have to be better again in order for their teams to feature later on in the tournament.

Israel Folau, at full-back for Australia, can create massive defensive issues for opposition teams if he given time and space. And even if he isn't. He is a player to whom Australia must get the ball early with space to allow him to use his electrifying pace. When he is around the ball something will always happen. He is a player able to create something out of nothing, and his kick return and connection with his backline will be vital if the green and gold are to fire.