Six Nations 2015: Six of the best get ready to rumble

You can’t buy history, and the oldest international tournament in the world, dating back to 1883, returns for the first instalment of a 15-match programme compressed into five of the next seven weekends. It will, as ever in recent times, fluctuate wildly and should be wildly open. In other words, it will be wild.

The Rugby Championship may be regarded as having a higher standard, and contains four of the world's top nine sides – including the top two. Yet, in addition to having a little more quantity as well as history, the Six Nations isn't exactly short of quality either, as it incorporates five of the world's leading eight sides.

Sitting atop them all in the rankings, at third in the World Rugby ladder, stand Ireland, who are also defending champions. But history has shown us that however hard it is to win the Championship, it is even harder to retain it.

The last Irish side to do so was the 1949 vintage, with the recently deceased Jack Kyle pulling the strings.

Only three of the 14 champions since Italy's admission expanded the Championship to the Six Nations in 2000 have retained the title – England in 2001, France in 2007, and Wales in 2013.

The Six Nations is an entity in itself. Always has been, always will be. Much as the IRFU and Irish rugby would love to go further than any Irish team has ever gone before at the World Cup later in the year, Joe Schmidt's paymasters have always underlined the importance of the Six Nations in its own right. Winning the title last year was a timely boon – as well as a boost to the union's coffers of about €1 million in prizemoney.

Yet, of course, this Six Nations will be viewed through the prism of the impending 2015 World Cup and understandably so. Ireland, France and Italy will be drawing lines in the sand prior to meeting again in their World Cup pool. Ditto Wales and England on opening night this Friday in the Millennium Stadium, which should ensure the 2015 Six Nations hits the ground running.

Recall too how England’s 2003 Grand Slam was a precursor to them winning the 2003 World Cup. Were Ireland to retain the title, and say beat France and Italy back-to-back, how much better equipped might they be come the World Cup? Certainly no Irish team would have taken such an impressive body of work into a World Cup.

As with Wales v England, Ireland’s opener in Rome will also serve as a precursor for their World Cup meeting – for the Stadio Olimpico read London’s Olympic Stadium. What’s more, it is followed a week later by a dress rehearsal of Ireland’s World Cup pool clash with France – for the Aviva Stadium, read the Millennium Stadium.

Recall, if you will, the sight of Bernard Laporte and his coaching staff punching the air in delight at the conclusion of their win at Croke Park in 2007. Afterwards, Laporte made no attempt to disguise French belief that their victory that day was a significant psychological blow with the 2007 World Cup in mind. So there's no getting away from the World Cup.

There have been four annual contenders of recent times who have each won the Six Nations in the last five years. To that quartet can genuinely be added a resurgent Scottish side, benefitting from both the customary lift from a new coach, in Vern Cotter, as well as the improved form of Glasgow and Edinburgh; witness their improved ranking of eighth in the world after their November series. This included a win over Argentina, which was more than France could manage.

Hence, the 2015 Six Nations is as fiendishly hard a competition to call as its recent predecessors. Much is made of momentum, and rightly so, but a team’s form can fluctuate over the course of five games in seven weeks, with injuries an huge factor.

For example, two seasons ago Ireland went to Cardiff and won on the opening weekend. Six weeks later, Wales were winning the title by routing England while Ireland were losing in Rome after failing to add to their opening victory. So much for momentum.

There’s little between England and Ireland in the betting, with Paddy Power making them joint favourites at 15/8. Ever mindful of heightened expectations, that would surely make Joe Schmidt twitch, even if it is the Schmidt factor as much as any player which is responsible for this.

Certainly Ireland ought to be as meticulously well prepared as any other side, which is just as well as an opening day meeting with Italy in the Stadio Olimpico is probably meeting the Azzurri at their most potent and fired up. When opening their campaign in Rome, they beat France two years ago, lost narrowly to Ireland four years ago (13-11) and England in 2008 (23-19), while beating Wales in 2003 and Scotland in 2000. Against that, there have also been some opening-day thrashings.

Ireland should be missing linchpin Johnny Sexton for that game, with the outhalf and others coming back to fitness (Sean O'Brien, Cian Healy and Iain Henderson) bound to be rusty. There are plenty of other injury concerns and Mike Ross being dropped by Leinster for their European Cup games in January won't help. Against that, it has to be a huge boon to have those aforementioned big carriers back in harness.

By Schmidt’s own admission, things fell Ireland’s way in November, when catching the Springboks a little undercooked and over-confident before nearly letting slip a 17-0 lead in leaking three tries against Australia.

They showed a determination to eke out wins whatever it took, even if they had set-piece issues, but the margins as ever are likely to be tight in several games and they are perhaps more dependent than most on a raft of key men – Paul O'Connell, Jamie Heaslip, Conor Murray, Sexton, Rob Kearney.

England have perhaps been ravaged by injury the most, with Joe Launchbury a huge loss and much hinging on the inexperienced George Ford, but then only the French rival them for strength in depth. They have won four out of five in each of the last four seasons, winning the title in 2011 but finishing runners-up for the subsequent three seasons and on points difference in each of the last two campaigns. That must give them every motivation in the world, albeit they have treks to Cardiff and Dublin.

France, as ever, could be wilder than anybody, all the more so under Philippe Saint-André. Their autumnal wins over Fiji and Australia were a breath of fresh air, and being stalled by a resolute Pumas on a gluepot is not something new for them or other sides. The Top 14 has taken a toll with one of their November finds, Alexandre Dumoulin, sidelined by injury.

It could be that Warren Gatland’s declared preference for getting Wales out of a World Cup pool also containing England and Australia will become a self-fulfilling prophecy, and that will give him breathing space and his squad a readymade excuse for not regaining a Six Nations crown. Alternatively, it could reduce the levels of expectation on him and his team.

Prior to last season, they had won the Grand Slam in 2012 and retained their title in 2013 – losing only to Ireland in those two years - which merely set them up for last season’s fall. Their status as bulk suppliers to the Lions made them a target for others, notably Ireland and England, who each beat them at home.

They have those two in Cardiff, and in addition to a low injury profile, a raft of front-liners are hitting form ominously. Rhys Webb and Dan Biggar have matured for Ospreys and Wales, and it was interesting to see Racing's Jamie Roberts and Clermont's Jonathan Davies carving up English midfields containing Luther Burrell and Brad Barritt on the final weekend of European Cup pool matches.

In any event, with their World Cup rendezvous against England in mind, and given the history of the Welsh-English rivalry, one can’t imagine the Red Dragonhood and their passionate fans wanting a victory over the auld enemy any less than before come Friday night.

Furthermore, if Wales win, they will then have the momentum to launch a serious tilt at the title.