Wales, England and Ireland vying for the title - Six Nations permutations
Wales head into the final weekend of the Six Nations knowing victory over Ireland will guarantee them the title and a Grand Slam.
Warren Gatland's side have impressed throughout this year's tournament, picking up four victories so far, including a 21-13 win over nearest rivals England in round three.
Make it five from five on Saturday and the title is theirs. Should they slip up, though, both England and Ireland could take advantage and snatch the Six Nations crown from Wales' grasp.
Here, we look at the permutations heading into the last round of fixtures.
Victory over Ireland will seal the title no matter how England do in the late kick-off. Maintaining their 100 per cent record in the 2019 edition earns Wales three extra bonus points, moving them out of their rivals' reach at the summit.
Should Wales fail to win in Cardiff, England will be certain to move above them with a bonus-point victory over Scotland. A win would also see Eddie Jones' side regain the Calcutta Cup.
Joe Schmidt's reigning champions are not out of contention just yet, though they need more than just a victory over Wales to retain their crown. Should they triumph on the road, Ireland will then require a Scotland win at Twickenham to leap into first place.
#GuinnessSixNations— Irish Rugby (@IrishRugby) March 12, 2019
In Pics: The Ireland squad were back training in the gym as they build towards Saturday's mouth-watering Guinness Six Nations final round clash with Wales in Cardiff.#TeamOfUs#ShoulderToShoulderhttps://t.co/pfFxK0lbuepic.twitter.com/ApsLy05mGt
Should Ireland secure a bonus-point win over Wales and England beat Scotland without scoring four tries, the two teams will finish level on 19 points
That would mean points difference would decide the championship. England currently lead the way, their total standing at 83 compared to Ireland's 19.