Ireland's status as the world’s best team is under threat from the reigning champions.
South Africa will replace Ireland as the number one ranked team in the world if they beat them at the Aviva Stadium on Saturday.
In fact, the result in Dublin will determine who finishes the weekend as the top-ranked side as France cannot improve their rating with victory over Australia due to the 7.33 rating points between the sides before home weighting is factored in.
New Zealand can only improve their rating by a maximum of one point.
Ireland could drop from first to fourth if they lose by more than 15 points or New Zealand beat Wales by the same margin if the Irish lose at home by less.
Second place will belong to New Zealand if a win by more than 15 points is accompanied by a Springboks loss and a draw or defeat for France.
South Africa can fall no lower than fourth with a heavy defeat in Dublin.
England can only improve on fifth if they beat Argentina by more than 15 points and New Zealand slip to defeat in Cardiff, a scenario which would see the sides swap places and condemn the All Blacks to equalling their lowest ever position.
It is possible for England to climb to third, but this would also require Australia to beat France by more than 15 points.
Australia can only build on last weekend’s three-place gain to sixth if they win by more than 15 points and England are beaten by Argentina at Twickenham.
If Australia’s margin of victory is smaller than Los Pumas must win by more than 15 points for the Wallabies to climb to fifth. Argentina will be the higher ranked of the two nations if they beat England by that margin with a climb of up to three places possible for Los Pumas depending on other results.
England could fall as low as seventh if they suffer such a heavy loss and Australia win. Wales will climb above a beaten Australia into sixth place if they can end a 69-year wait for victory over New Zealand. However, they could drop two places to ninth if beaten, slipping below a defeated Argentina and Scotland side that are victorious against Fiji.
Scotland can only gain a maximum of 0.23 rating points for victory, leaving them relying on other teams losing to improve their position of ninth.
Fiji must win by more than 15 points to return to the top 10 for the first time since September 2019, with ninth place possible. Samoa will drop below Fiji into 12th if both teams are beaten on Saturday.
Italy will overtake Georgia and Samoa in the rankings and move to 12th place if they beat the latter by more than 15 points.