|Guinness Six Nations|
|Dates: 1 February-16 March|
|Coverage: Watch live coverage on BBC TV, BBC iPlayer, Connected TVs and online; listen to match commentaries, shows and podcasts on BBC Radio 5 live, sports extra and BBC Sounds; follow text updates on the BBC Sport website and mobile app.|
The finest teams in the northern hemisphere, packed sporting cathedrals, millions watching from around the world and all played out in the shadow of the autumn’s Rugby World Cup.
The stage is set for a spectacular 2019 Six Nations.
With Wales preparing to face France in Paris in the first match on Friday at 20:00 GMT – a match you can watch live on BBC One – BBC pundits have been predicting this year’s plot twists.
What match are you looking forward to the most?
Former England scrum-half Matt Dawson: France v Wales this Friday night. Nobody is talking about these two teams and yet their squads are seriously dangerous. If Wales nick it a final-round title showdown in Cardiff against Ireland is on the cards.
BBC rugby union correspondent Chris Jones: Where to start? Ireland v England is a hugely significant match on the opening weekend. But a Wales v England game in Cardiff is always special. This year it will take place in the third round of action – at the central point in the Championship – and could even be a dry-run for a World Cup quarter-final. Titanic.
In terms of atmosphere, travelling support, and history, it also doesn’t get much better than a Scotland v Wales game at Murrayfield.
Former England centre Jeremy Guscott: It is so difficult to choose because the results change the significance and weight on each match as the tournament gets going. On paper you looks at the three games that pit England, Ireland and Wales together, but it could all change.
Who will be the breakthrough stars?
Jones: Scrum-half Tomos Williams is being talked up by plenty of those in the know in Wales, and a strong showing this Six Nations could settle the will-he-won’t-he Rhys Webb World Cup saga. I’m also hoping another rookie number nine, Antoine Dupont of France, gets a chance to try and translate his club form onto the international stage.
Dawson: Wales’ back row has a habit of delivering sparkling talent and Aaron Wainwright looks the business. From an Irish perspective I’m looking forward to seeing Chris and Tom Farrell – no relation to each other or defence coach Andy Farrell – brighten an already scintillating backline.
Guscott: He may have a job breaking into an Ireland team that contains the likes of Jacob Stockdale and Keith Earls, but the ferocity of the contests might mean that Jordan Larmour gets a run. I would love to see him do well because he is not overly big, but compact, elusive, with wonderfully tricky footwork.
Where, if anywhere, is Ireland’s weakness?
Former Ireland wing Shane Horgan: Ireland are not going to drop off a cliff in terms of form, talent or quality, but you can lose games in the Six Nations.
They can start slowly in the Six Nations – it took a last-minute drop-goal by Johnny Sexton after 40-plus phases to beat France last season. England’s power game is what will worry Ireland on the opening weekend. It depends on selection, but Manu Tuilagi could disrupt Ireland.
Later in the tournament, it doesn’t fall brilliantly for Ireland. They have got Italy in between the two break weeks. If Joe Schmidt decides to rest his senior players, they will have four weeks off, which is maybe too much away from the frontline.
Finally they have a six-day turnaround between France at home in the fourth round and a potential title decider away to Wales on the final weekend.
Dawson: The only weakness I can see is in depth at scrum-half. Conor Murray is so influential I feel there’s a significant gap to the rest now that Luke McGrath is out and Kieran Marmion just back from injury. All eyes will be on Murray. He will be getting a lot of attention.
Can Scotland translate Edinburgh and Glasgow’s Champions Cup highs to real progress?
Former Wales flanker Martyn Williams: Edinburgh and Glasgow have done excellently but to take the next step Scotland have to beat big teams away from home.
At Murrayfield they are formidable and it won’t be a surprise at all if they turn over either Wales or Ireland there this year.
Away from home though it is a different story. They have not won away to Ireland since 2010, away to Wales since 2002, away to France since 1999 and it is way back in 1983 that they beat England at Twickenham.
To make it even more difficult Scotland have a long injury list with the likes of Hamish Watson, John Barclay, Richie Gray, Duncan Taylor and Mark Bennett among those sidelined.
They have some quality individuals in Tommy Seymour, Finn Russell and Stuart Hogg and a nice opener against Italy to build confidence.
They are really well coached by Gregor Townsend and will be tough to beat, but to lose Watson and a host of front-row players, you can rule them out from winning the whole thing.
Dawson: Two home fixtures is the perfect start for the Scots to build on their European form. Momentum is always key in the search for consistent success so I’m sure Gregor is emphasising exactly that.
They are in a similar place to where Ireland were 10 years ago. Their form at home is solid but they are hit or miss away. But Scotland now should believe they have the power and guile to beat the best. Mental application is crucial.
How much will Eddie Jones relish England’s underdog status?
Former England centre Jeremy Guscott: There is a side to Eddie Jones’ Aussie psyche that might relish proving people wrong and upsetting the rankings. Last year, England came into the Six Nations as winners of the previous two tournaments. This year they have both Ireland and Wales above them in the world rankings.
The way the fixtures have landed they have got to go to both Dublin and Cardiff. It will be a huge statement to the rest of world rugby if they can beat Ireland away this weekend.
When you look at the personnel at his disposal, there is the basis for a serious chest-on confrontational game with the ball in hand.
A front row of Mako Vunipola, Jamie George and Kyle Sinckler, a second row of Maro Itoje and Joe Launchbury and Billy Vunipola at number eight adds up to six really powerful runners who can cause some damage.
In the backs he will hope to have heavy-duty ball-carriers Manu Tuilagi, Ben Te’o, and Joe Cokansiga all fit at the same time.
It is a different, more dynamic, confrontational England, which we have not seen too much of, and it might create space in wide channels for Elliot Daly and Jonny May to exploit. It is going to be interesting to see what develops.
Have Wales been flying under the radar despite nine wins from nine?
Jones: Wales were flying under the radar, but not any more, with Warren Gatland happy to talk up his side’s chances. Who plays at fly-half is key. Dan Biggar has been a warrior for Wales – and will be again – but the Welsh management need to find out if they need a more creative option at stand-off to win the World Cup.
Rhys Patchell is a lovely player but the 12-6 defeat by England at Twickenham last year exposed his temperament, so enter Gareth Anscombe – who has both the all-round game and the mentality to prosper at the highest level. Will he get an extended run this Championship to show he is Wales’ World Cup playmaker?
Guscott: Wales should have no fear of going to France in their tournament opener – they have a very good record against them in recent years both home and away – and then they play Italy in the second round of fixtures. That could build a head of momentum.
As a competition, the Six Nations has three of the four top teams in the world. It is a showpiece of world rugby and Wales are a key part of that.
What might be the controversies of the tournament?
Jones: The way high and dangerous tackles are officiated will be a major talking point. Domestically this season, it has been a mess, with referees in European competitions dealing with challenges much more harshly than in the leagues, while the “Farrell flashpoints” of the autumn only muddied the waters further.
And what about the breakdown? Both in terms of safety and interpretation, it is rugby union’s version of the Wild West. For the millions of casual rugby fans – who may only watch the Six Nations – it all must seem a complete mystery.
Guscott: The referees have the toughest job and I commend them for what they do. For the game to flow though, I would love to see them focus on the breakdown area. Too many players are dropping their hands and elbows onto the floor on their way to getting hold of the ball. For me that should be a penalty, you should have to go straight for the ball.
Great ‘jackalling’ is a good part of the game, but there is too much of the marginal stuff that is slowing and stifling the game.
Who will win?
Williams: Ireland. You can only go on past performances really, but anyone of them, England and Wales could win it. France could be a curveball.
Dawson: Ireland are overwhelming favourites for both the Championship and Grand Slam so what an opportunity to show the rugby world how adept they are at carrying that pressure.
Only complacency can beat them but this is the Six Nations and history shows the underdogs tend to nibble the heels of its owner.
Guscott: Ireland, it is not a difficult pick for me. If they play at their top level, they are the best team. Complacency is a possible threat to them, but the way that Joe Schmidt runs that camp I can’t see it taking hold.
Jones: Whoever wins in Dublin on the first Saturday I think will be brilliantly placed to win the whole tournament. Against my better judgement, given they haven’t scored a Six Nations try in Dublin since 2011, I’m going for England.