By Brendan Cole
This meeting of Ireland and England is a clash to savour between the only two teams still capable of claiming the Grand Slam this season.
Ireland’s victory over a weakened Wales and France's chaotic loss to Italy reduced the number of viable Grand Slam contenders by half last week. Of course, victory here does not mean a sweep for either side.
Ireland would still have to overcome a French side that has a phenomenal record in this fixture over half a century and two teams in Scotland and Italy that have shown the capacity to produce big performances in any given week.
A win for England would also only be the first stepping stone, with France set to visit London in the next round and a final fixture against a Welsh side that could well have found its form by the middle of March.
In any case, arguably more interesting is the fact that this match comes at a critical stage in the evolution of two evolving squads.
Who is on a true upward curve and who is about to be exposed?
Taking Ireland first, the attacking masterclass of the first 43 minutes against Wales confirmed that Ireland had indeed found something new in November. The teamsheet, at least in terms of the startintg XV, seems to clearly reflect the very best of Irish rugby.
Scepticism has been replaced by cautious optimism.
On the English side, Stuart Lancaster's new approach has resulted in earlier than expected dividends in the shape of a victory over New Zealand in November.
There are doubts about both teams. For Ireland, discipline, the quality of the players on the replacements bench and, inevitably given the events of last March, the scrum, are at the forefront.
For England, doubts include playmaking ability, the capacity to hit a high tempo and the unsophisticated game plan.
England shunned the wide areas last week, playing in groups near the ruck and looking to trouble Scotland with short passes and offloads, often in static positions.
Will a similar approach, designed to bring brute strength and technical competency to bear, be enough to uspet Ireland's defence?
Under Anthony Foley, Ireland have been pro-active and positive in defence, making better decisions on when to choke and when to just hit.
Discipline is still an issue. Ireland conceded more penalties than any other side last week (15) and incurred two yellow cards in the second half. They may find the yellow is produced even more swiftly this time with Jerome Garces on the whistle.
Getting the split second choice on whether to attempt a strip on the deck or not right is key. Ireland will need turnovers.
Looking at the English pack, Dan Cole, Geoff Parling, Joe Launchbury and Tom Youngs are good operators in general play and excellent set piece players, but they are not the type of destructive tight five players that Ireland have struggled against in the past. Joe Marler can be more impactful but is only one of five.
In the back row of Chris Robshaw, Tom Wood and James Haskell, the sense again is of high quality players slightly short of that ability to make exceptional plays.
They may well miss the structure busting carries of Ben Morgan. That said, England are strong athletically and Ireland may find it harder to shift them in the ruck than Wales.
Ireland, through the likes of Mike McCarthy, Rory Best and Sean O’Brien, look to have more individuals capable of shifting the momentum.
The style is also different. As a group, the Irish pack has been released to play more rugby in the wide areas and a high tempo has been given priority over getting into perfect shape alongside the ruck.
That urgency has given a boost to Conor Murray and Jonathan Sexton, and both are playing at the top of their form while in the centres, Brian O’Driscoll and Gordon D’Arcy have also benefitted from the additional space and time.
Will England get as much from their half-backs?
Ben Youngs and Owen Farrell do most things well, but Youngs' pass can be ponderous and while he has pace, he can make the odd error when the tempo lifts.
And while Farrell rarely does anything wrong, and created a highlight reel score with a long pass last week, he has not yet shown the speed or consistent playmaking ability of Sexton.
In general, Ireland’s attack may just be ahead on organisation and tempo.
The set piece is, of course, the potential Achilles heel for Ireland.
It has been well flagged that England will seek to get into the Irish scrum. They may find that difficult, not least because Mike Ross will face a different pair of direct opponents than last year with Alex Corbisiero injured and Hartley on the bench.
The Irish scrum has been more than respectable since Twickenham and a better effort is to be expected.
The English lineout could also be strong. Parling is a specialist at both reading and jumping to contest and Ireland will need Donnacha Ryan to get his calls right, and Best’s throw to be on song. Ryan took five balls himself last week but may need to vary things that bit more.
But Ireland need only do reasonably to bring their attack into play.
More than any game, this could shift around the hour mark.
England, with Manu Tuiliagi, Danny Care and a collection of big, powerful forwards including both Vunipola brothers and Courtney Lawes on the bench could finish the match with a better XV than they start with.
They could also be one of the heaviest packs in history, with an average weight of over 19 stone a man, if Lancaster brings all the subs on.
Ireland would do well to have a certain amount of control over the game with 15 to go as England look primed to finish well.
Other factors – a big performance from Rob Kearney or either one of Ireland’s young wingers, an injury to Ross or either of the Irish centres, or an early entry and subsequent tour de force from a Billy Vunipola or Tuilagi – could change everything.
But with more experience and an edge in terms of proven quality in key positions, Ireland can nick this one.
Match prediction: Ireland 23-15 England
Ireland XV: Kearney, Gilroy, O’Driscoll, D’Arcy, Zebo, Sexton, Murray, Healy, Best, Ross, Ryan, McCarthy, O’Mahony, O’Brien, Heaslip (capt).
Replacements: Cronin, Kilcoyne, Fitzpatrick, O'Callaghan, Henry, Reddan, O'Gara, Earls.
England XV: Goode, Ashton, Barritt, Twelvetrees, Brown, Farrell, B Youngs, Marler, T Youngs, Cole, Launchbury, Parling, Haskell, Robshaw,(capt), Wood
Replacements: Hartley, Wilson, Vunipola, Lawes, Waldrom, Care, Flood, Tuilagi.