For the first time in Rugby World Cup history Six Nations teams could complete a clean sweep and finish in first place in the standings in all four pools.
England are already guaranteed top spot in Pool D, Wales in a very strong position in Pool C and France and Ireland are favourites to finish top in Pools A and B, with all four teams coming up against lower-ranked opponents.
And in terms of the World Rugby Men’s Rankings powered by Capgemini, it would take something extraordinary for a northern hemisphere team not to be at number one at the weekend’s end.
Ireland’s 15-month reign at the top of the rankings will continue if they manage to beat Scotland and book their place in the quarter-finals.
Andy Farrell’s team have held top spot since July 2022 and that position is not in any danger if they do the business against a Scotland side that needs to win to have any hope of reaching the last eight.
However, Ireland, with a rating 10.36 points higher than fifth-ranked Scotland, will be replaced at number one by France if Les Bleus beat Italy in a pivotal Pool A encounter and the Irish lose by any margin on their return to Stade de France, where they beat South Africa earlier in the tournament.
An Ireland defeat to Scotland by more than 15 points – something that has only happened seven times in 141 previous meetings – would see them drop to fourth with their Celtic rivals climbing to a new high of third and South Africa moving up one to second.
More significantly, such a scenario would also see Ireland miss out on the quarter-finals if they fail to score a try bonus point in defeat.
It would also result in New Zealand, who play Uruguay in the first of the fifth-round matches on Thursday, falling one place to fifth, equalling their lowest position since the rankings were introduced in October 2003, even if they beat Los Teros.
South Africa, despite not playing, could strike a blow for the south and end the weekend as number one. But this would require Ireland and France to both lose by more than 15 points – a sequence of results that would take Scotland to second above Ireland and France.
Japan and Georgia eye place in top 10
England, Wales and Fiji – ranked sixth to eighth – are also unable to improve their ratings with victory over Samoa, Georgia and Portugal respectively. But it is possible for them to still move up the rankings if teams above them lose sufficient points.
One side who can profit from victory are Japan, who will jump three places to ninth if they beat Argentina to confirm their place in the quarter-finals for the second successive tournament.
Los Pumas would fall two place to 11th with another pool-stage exit, three if the margin of defeat is by more than 15 points.
If Argentina reach the quarter-finals in style with a win by more than 15 points and the higher-ranked teams above them win their matches, eighth place will be theirs for the taking.
Italy could also shoot back into the top 10 if they end a 13-match losing run against France and secure their first victory over Les Bleus since 2013, potentially to a new high of sixth if Argentina, England, Fiji and Wales also suffer defeat.
Japan stand to fall two places if they lose and Georgia and Samoa beat their higher-ranked opponents, Wales and England.
If they can repeat their victory over Wales from last November, Georgia would climb two places to equal their record high of 11th if Italy and Japan are beaten this weekend.
A win by more than 15 points could take the Lelos into the top 10 for the first time – to as high as eighth – and see them ranked above Pool C rivals Wales and Australia.
Historic high possible for Portugal
Tonga cannot improve on 16th place even if they beat Romania by more than 15 points as the sides above them will lose nothing with defeats to higher-ranked teams. The ‘Ikale Tahi can only close to 0.66 rating points behind their Pacific Island rivals Samoa.
Romania will fall one place to 20th, swapping places with Spain, if beaten by Tonga. However, the Oaks would become the higher ranked of the two nations if they beat Tonga in their first Rugby World Cup meeting.
Tonga will drop two places to 18th in defeat, even if Portugal and Uruguay are also beaten – by Fiji and New Zealand – with 19th possible if they lose by more than 15 points to Romania.
Such a scenario would see the sides swap places with Romania jumping four places to 15th – their highest position since February 2022.
Even in victory, Tonga will fall one place if Portugal beat Fiji to claim their first-ever Rugby World Cup victory, a result which could lift them to a new high of 14th.
Defeat could scupper Fiji’s hopes of reaching the quarter-finals for the first time since 2007, while also seeing them drop out of the top 10, depending on other results.