The 2015 Rugby World Cup is well underway and it's already had its first big upset with South Africa losing to Japan 32-34.

For the 43,000 punters taking part in the TAB's, pick which teams will win at the World Cup, their dream of winning the $1 million is over.

Here at SunLive – my work colleague Zoe Hunter and I have a little side bet going on.

Over the next few weeks, we will choose who we think will make the top four and who will go on to the finals and win the William Webb Ellis Cup. Not only that but we will also pick how well the All Blacks will go throughout the tournament.

To make it a bit more exciting we have asked a couple of sporting experts to join our teams. Zoe has invited kayaking star Luuka Jones, while I've asked Steamers coach Clayton McMillan to join my team.

Now you may ask, what does the winning team get? It's simple, bragging rights and of course the loser out of Zoe and I, has to shout the other morning tea. I've already picked what Zoe is going to shout.

So here are the rules; Over the next few weeks, each competitor gets a point for choosing which team wins in the All Blacks' pool match and the competitor with the closest points in the match gets a bonus-point of three points.

The competitor with the correct top four come semi-finals, gets four points and the competitors who choose the finalists and the winner of the final get four points as well. At the end of the tournament, the team with the most points is declared the winner.

During the tournament each competitor can change their top four up until October 8. The day before New Zealand's last pool match against Tonga.

Good luck Zoe, you're going to need it.

Here are our picks and why:

Girls' Team:

Zoe's Picks:

Top Four:

NZ, Australia, South Africa and England

Reasons: As a Kiwi, the boys in black are an obvious choice but a loyal one. Plus we've totally got the cutest boys in the tournament! They're definitely the team to beat. Nehe Milner-Skudder is my player to watch. Strong, fast and blessed with the ability to side-step better than any salsa dancer, the 24-year-old full-back/wing will be the reigning champions' sharpest weapon.

I'm ashamed to admit it, but the Aussies are my second pick. They're looking quietly confident coming into the tournament buoyed by victories over the AB's and Springboks in The Rugby Championship.

South Africa's hurt egos after losing every match of their Rugby Championship campaign may be their fuel for coming into the World Cup with a determination to win.

England will have a determination to win this thing, especially because the World Cup is hosted on their turf this year.

Finals:

NZ v England

Reasons: I read somewhere that while England are ranked fourth in the world, behind NZ, Australia, and South Africa, they have a 30 per cent chance of reaching the final. This is second to NZ, whose chances are rated at 56 per cent.

Pool play:

NZ v Argentina

Reasons: I'm picking All Blacks to win by 21 points. My prediction is based on their last meet in July, when the ABs beat the Pumas 39-18.

Ma'a Nonu may be right in calling Argentina's bluff, saying: 'They can roll anyone, especially at World Cups”, I'm still staying loyal to NZ. Bring it on Argentina!

Luuka Jones' picks:

Top Four:

NZ, Ireland, England and France.

Finals:

NZ v Ireland

Reasons: Definitely backing the All Blacks going into the World Cup with me being a proud Kiwi and them being the best team in the World. England in my top four being the home team and France are always solid world cup performers.

I've chosen Ireland to be in the final, they will be fighting hard for it and will have a lot of supporters over to cheer them on. They took out the six nations earlier this year and are showing good form.

I don't want to see another France vs NZ final, its too nerve wracking! I'm picking a NZ v Ireland final with NZ to win.

Pool play:

NZ v Argentina

Reasons: I'm picking All Blacks by 24 points. My reason is that the All Blacks are going to assert their dominance from the start and play the same as they would want to in the final.

Boys' Team:

Greg's Picks:

Top Four:

NZ, France, England and Argentina.

Finals:

NZ v England

Reasons: My reason being New Zealand have to be the favourites going into the tournament, I've chosen Argentina as my underdog team who have played well and have built well leading up to the RWC.

I've chosen England because you can't count out a home side in a tournament because home crowds lift sides. I've chosen France because they always lift for RWC and they are long overdue to win the cup.

At this stage I'm picking a New Zealand v England final. New Zealand to win

Pool play:

NZ v Argentina

Reasons: I'm picking All Blacks by 12 points. My reason is both teams will be a little rusty and the ABs are always slow starters in the tournament. Argentina while they will be hungry and passionate, they won't be able to match our side.

Clayton McMillan's Picks:

Top Four: NZ, Australia, Ireland and England

Reasons: Just England on the basis that they have probably played their worst game against Fiji. The home ground factor is a big one.

Ireland have probably been, consistently the best European team over the last couple of years. They have a good route to the final four.

Australia, it would probably pay to take more notice of the game, when they beat the All Blacks as opposed to when they lost the following week.

Pool play: NZ v Argentiana

Reasons: New Zealand 13+, I think Argentina will probably be in it for a long period of time. But we'd come away with it in the end. I think we've just got too much X-factor. Argentina will bring a lot of emotion but we'll just weather the storm and then kick home late in the game.