irb.com and James Mortimer 14.Sep.2013Getty Images
The All Blacks, who have occupied top spot for 82 per cent of the time since the rankings were introduced in October 2003, currently have a 2.7 rating point cushion over South Africa at the halfway stage of their Rugby Championship title defence.
However, if South Africa can end New Zealand's run of 30 consecutive victories at Eden Park then that deficit will be turned into at least a 0.44 point advantage. If Heyneke Meyer’s men can win by more than 15 points then South Africa would enjoy a cushion of just over two points.
Their first loss of this year’s Rugby Championship, though, could see South Africa, one of only three sides to occupy the number one spot in the history of the rankings, slip back to nearly four rating points behind New Zealand if the All Blacks were to win by more than 15 points in Auckland.
While the Eden Park encounter brings together two unbeaten sides, the weekend’s other Rugby Championship match in Perth involves two sides who are still looking to break their duck in 2013 after three losses.
Argentina will arguably go into the match at Patersons Stadium with greater confidence after their performance against the All Blacks in the 28-13 loss last weekend, and a first Rugby Championship victory will lift them one place to ninth at the expense of Scotland.
Australia, still to win under new coach Ewen McKenzie, will remain fourth – albeit just eight hundredths above France – unless they lose by more than 15 points. In this event, the Wallabies will fall two places to their lowest ever position with Argentina closing to within two tenths of Ireland in eighth.
A victory for Australia on home soil will have no impact on the rating of either side with six places and more than seven rating points separating the two teams.