Scotland and Wales meet at Murrayfield on Saturday in what is effectively a Six Nations title eliminator: the winner will remain - mathematically at least - in with a chance of winning the championship in the final round.
The lure of a potential showdown with England in Cardiff awaits the defending champions, while Scotland travel to Paris - where they clinched their last title in 1999.
While Wales have won eight of the countries' last nine Championship meetings, Scotland are aiming to win three matches in a row in the tournament for the first time since 1996.
Statistically, the teams look evenly matched after the first three rounds: same number of points, tries, conversions, penalties, clean breaks, kicks from hand, line-outs won.
So what patterns can we discern from the evidence so far, and which areas will be crucial to the outcome on Saturday?
Former Scotland scrum-half Andy Nicol (AN) and former Wales internationals Jonathan Davies (JD) and Martyn Williams (MW), all part of BBC Sport's coverage at Murrayfield, help dissect the issues.
I thought possession was nine-tenths of the law? Scotland seem to be disproving that theory...
Scotland had 38% of the possession against Italy, and 29% against Ireland, yet won both games.
AN: "It is definitely a tactic for Scotland that they don't want the ball in their own half. You can have as much possession as you want, but if you don't have it in the right areas of the park, it is ineffective. In the last few years Scotland have topped stats for territory and possession but lost on the scoreboard. I know which I would prefer.
"But there is no way they will win another game like the Ireland one with the same amount of possession. Wales, with the quality of their backline, will convert those opportunities into tries."
JD: "If Wales have that amount of possession against Scotland, there is only one winner and it will be a clear points victory."
The breakdown is key to every Test these days. And Sam Warburton is back for Wales...
MW: "It is one area where Scotland have really struggled. England absolutely annihilated them there. [Scotland coach] Scott Johnson's theory is to keep the ball in hand and move defenders around, but they lack control at half-back. With how good the Welsh back row are at the contact area, I think Wales can have a real go at them there."
AN: "I'm a big fan of Warburton and he is a quality player but he has a lot to prove. Sometimes people react well to that situation and sometimes they try too hard. If you try too hard in his [open-side] position, you run the risk of giving away penalties. If Warburton is just a bit too excited about proving a point, he might start going for balls that are lost and give away penalties. And Greig Laidlaw proved against Ireland that if you give Scotland penalty opportunities, he is going to take them."
What other area might Wales look to exploit?
JD: "There is a clear weakness in the Scottish midfield and Sean Lamont is a wing playing at centre, which is a defensive position. Sometimes he runs up and down and doesn't know where to go. If Wales can target him with dummy runners, I am sure they will get some results there.
"If they can put [wings] George North or Alex Cuthbert into one-on-ones with the Scottish defence, it is a very tough tackle for anyone."
AN: "Scotland's first-up defence has to be rock solid. That was lacking against Ireland, but was in evidence against Italy. But Wales are a much more potent attacking force than Italy, so this is a big step up.
"Possibly the threat of Wales centres Jamie Roberts and Jonathan Davies also came into Johnson's thinking in changing his fly-half, because two of Ireland's line-breaks came through Ruaridh Jackson's channel.
"Duncan Weir not only brings a tactical kicking game; he is a brave wee player and throws himself into tackles. Maybe after Jackson missed a couple, it affected the confidence of those outside him. But Scotland scrambled really well out wide. [Wing] Sean Maitland is a really intelligent rugby player and makes good decisions with or without the ball."
The back-three battle is certainly one to savour. Lions contenders all?
AN: Wales probably have the most potent backline in the Six Nations and the Scottish back three have all scored tries and looked dangerous in attack, so something's got to give on Saturday. No disrespect to some of the English and Irish lads, but all six of the respective back threes are going hell for leather against each other for Lions places.
"[Full-backs] Leigh Halfpenny and Stuart Hogg could well be on the plane together. I can't see all four wings making it, but North and Cuthbert are in the mix, Tim Visser has had plenty of air-time with his try-scoring exploits, and Maitland is coming up quietly on the rails."
JD: "Halfpenny has been the form player for a while now but if you look at New Zealand and Australia, they have attacking full-backs, and at the moment I feel Hogg has the edge in that area for the Lions spot. But Halfpenny has the edge in almost every other area."
So will Wales prevail? Or will Scotland create their own piece of Six Nations history?
AN: "I can undoubtedly make a case for Scotland winning. If they can beat Ireland in those circumstances, they can win any game of rugby. You can't quantify how much players get from winning games, particularly games you shouldn't have won. Winning is infectious and this Scotland team is full of confidence right now."
MW: "As well as Scotland have done, they were lucky against Ireland and I think Wales will be too strong for them."
Andy Nicol was speaking to BBC Sport's Bryn Palmer. Jonathan Davies and Martyn Williams were speaking on BBC Wales' Scrum V programme.