Six Nations champions England may be bidding for a Grand Slam when they face Ireland this weekend but they won't be the only team with something to play for on Saturday's final day of the Championship.
The climax to the 2017 Six Nations also marks the last round of international matches before the 2019 World Cup pool draw takes place in the Japanese city of Kyoto on May 10.
Leading teams will be split into three bands of four based on their position in the world rankings for a seeded draw.
The aim is to prevent too many of the world's leading nations ending up in the same pool ahead of the quarter-finals and ensure an even spread of competition in the group phase.
Only the top two sides from each of the four pools will go through to the last eight at Japan 2019, so the better your world ranking or seeding, the more chance you have of qualifying for the knockout stages.
Not that it always works like that in practice.
Wales had dropped down to the third tier for the 2015 World Cup and found themselves in a pool with England and Australia.
But it was hosts England who missed out on the quarter-finals following successive defeats by Australia and Wales at Twickenham.
By contrast victory in Dublin on Saturday would see England set a new record of 19 consecutive Tests wins by a leading rugby union nations, beating the mark of world champions New Zealand.
Defeat for the Irish would see them drop out of the top band if Wales beat France in Paris.
France could find themselves in the same World Cup pool as New Zealand and South Africa for example, if they lose by more than 15 points to Wales in Paris and drop out of the top eight.
In that case, Argentina would move into the top eight and the Pumas would also climb the rankings if Scotland lost by more than 15 points to Italy.
Current World Cup draw bands
Band One: New Zealand, England, Australia, Ireland
Band Two: Scotland, Wales, South Africa, France
Band Three: Argentina, Japan, Georgia, Italy
Note: These are the 12 teams that qualified based on their top-three finish in pool play during the 2015 World Cup. The other eight teams for the 2019 World Cup will emerge from a global qualifying process.
Leading World Rugby Rankings
1. New Zealand 94.78
2. England 91.02
3. Australia 86.35
4. Ireland 83.18
5. Scotland 82.18
6. Wales 82.16
7. South Africa 81.79
8. France 81.21
9. Argentina 79.91
10. Fiji 76.46
11. Japan 74.22
12. Georgia 74.14
13. Tonga 71.94
14. Italy 71.17