Australia and New Zealand should reveal much about their approaches to the Rugby World Cup when they clash in the Tri Nations tomorrow.
Both have named teams close to full strength for the match, drawing a contrast between Australia's youth policy and New Zealand's reliance on experience.
New Zealand have named the oldest and most experienced starting line-up in their history and Australia a team of ambitious youngsters undeterred that the Wallabies have not beaten the All Blacks at Auckland's Eden Park in quarter of a century.
The winner will take a psychological advantage heading toward a World Cup in which, as the two top-ranked teams in world rugby union, they are seeded to meet in the final on October 23.
Both teams have rested key players in their opening two Tests of the season, against Pacific Islands opponents and an understrength South Africa.
But both have strengthened their line-ups for a Test which will decide the Bledisloe Cup and possibly the outcome of the Tri Nations, as well as the edge going into the World Cup.
A win for the All Blacks would leave Australia without a win in New Zealand in 11 years, and extend a bleak record at Eden Park, where the final and most significant World Cup matches will be played.
If the Wallabies win, it will inject a genuine belief the team can win the World Cup on New Zealand soil, while planting a further seed of doubt in the minds of the All Blacks, who have generally underachieved in rugby's showpiece event.
New Zealand did win the inaugural World Cup on home soil in 1987, but in each tournament since they have come up short. That consistent failure to deliver on World Cup expectations has left confidence fragile among the All Blacks, a situation that will be exacerbated if they lose tomorrow.
Following this weekend's game, both teams will each have only two Tests remaining before the World Cup begins, leaving little opportunity to correct any flaws that come to light at Eden Park.
Those considerations and an undercurrent of tension between the teams promise a vintage encounter. Steve Hansen, the New Zealand assistant coach, said this week that the Wallabies no longer respect the All Blacks after Sekope Kefu, the Australia prop, portrayed them as an ageing team on the wane.
Australia beat New Zealand in their previous meeting in Hong Kong in October, denying the All Blacks an unblemished season. At the same time New Zealanders resent any suggestion of Australian cockiness.
All these elements add fuel to the fire and have led to the sale of more than 50,000 tickets, promising the largest crowd for a rugby Test in New Zealand in recent times.
"It always seems the biggest game of your life seems to be the next one against the Aussies," Conrad Smith, the All Blacks centre, said.
"They're never short of confidence, but they've got the form to back it up. They're a massive threat and it keeps us on edge, so I don't think it's a bad thing."
Robbie Deans, the Wallabies coach, said neither team would skimp on effort, given the importance of tomorrow's match.
"There will be a lot of rugby played," he said. "Neither side is going to walk off the ground without having chanced their arm. Neither side wants to come second.
"Saturday is a great occasion. It will be an epic Bledisloe encounter and there have been some great ones over the years."
Graham Henry, the All Blacks coach, also stressed the importance of the match.
"It's game one in a two-match Bledisloe Cup series involving the teams ranked number one and two in the world," he said.
"It's a hugely important Test and is going to be a massive challenge, but we are looking forward to that. Our ability to play the game correctly is going to be very important.