England is invariably the Big One, but all the more so nowadays given they are the ultimate yardstick. Of all Ireland's 10 Tests this year none stands out quite like this afternoon's trek to Twickenham, though none will be quite as testing either.
It is the venue of least joy for Ireland, yielding just one win in two decades, yet buoyed by the handsome win over Wales and believing all the pressure is on the world champions to provide a triumphal homecoming for an expectant Twickenham, Ireland have travelled with confidence - a mite too much confidence seemingly for England's liking.
Bumping into Lawrence Dallaglio at Twickenham yesterday gave the impression that England are really up for this game, in part because they sense Ireland are a bit too chipper. This was reinforced by Clive Woodward's response to what was, surely, a tongue-in-cheek comment by Brian O'Driscoll. The Irish captain was reported, in his BBC online column, as saying: "Hopefully we can give the prawn sandwich brigade at Twickenham something to choke on."
When this was put to him, Woodward smiled wryly. "I'm surprised teams haven't learnt that about England: it's just best to keep quiet. We've had it in Scotland, we've had it from Ireland and no doubt we'll have it from Wales. We do our talking on the pitch. I've nothing to say to Brian apart from I don't eat prawn sandwiches. I prefer chicken and tomato."
It wasn't quite Clint Eastwood with a thin cigar in the corner of his mouth, but the veiled intent was there all the same.
"We know their players well, we know their strengths, very little has changed. We've got a lot of respect for their forward pack, especially at set-pieces, and we've a lot of respect for their half-backs, and that always makes for a dangerous international team. We know that on their day they can beat any team so we've probably prepared better for this game. We're ready to go."
The statistics couldn't be more daunting for Ireland. England simply don't lose. They have routed Ireland the last two occasions the sides have met, won 24 of their last 25 games, and won their last 22 at Twickenham.
Yet England actually look a little more vulnerable than they have in some time. There is no specialist or experienced cover at loosehead, no specialist reserve lock, no "enforcer" in the second row, no Jonny Wilkinson and no Mike Tindall in a midfield that could be vulnerable to the dancing feet of O'Driscoll and Gordon D'Arcy.
Jason Robinson is possibly more containable at centre while at full back Iain Balshaw, an Achilles heel when Ireland memorably denied England the Grand Slam in Dublin three years ago, didn't convince in Murrayfield.
Woodward conceded England haven't been at their best in beating Italy and Scotland, but also admitted, no less than anyone else, "I'm not sure what our best is." Woodward's "winning" mantra, though repeated yesterday, was always something recited at the behest, one suspects, of Martin Johnson. Dallaglio is more of a kindred spirit, and has admitted England didn't flow like honey in the World Cup.
However, in searching for a broader vision, England may have blurred their landscape. With four wingers, to all intents and purposes, in their ranks, it's clear they are designed to play a wide game, yet lately their forwards have overcooked things and cluttered the outhalf channel. You sense they need to restore precision and order to their play.
All of this will make them either more vulnerable or more lethal than they've been since last summer, especially if the young guns are sprung from the bench.
What of Ireland? Winning the ball has been a long-standing virtue of this pack, and though Steve Borthwick is an ace poacher, they should obtain possession. The maul and Ronan O'Gara's kicking game look like Ireland's likeliest means of go-forward ball, though O'Driscoll's and D'Arcy's elusiveness and ability to offload will test the English midfielder.
Without Geordan Murphy, whose "trailer" runs would have been ideal in the slipstream of this centre pairing, and Denis Hickie, Ireland aren't really equipped to play the wide, see-saw game they unveiled in the Grand Slam decider last season. But, you sense, they need to keep hold of the ball today more than they've been doing of late, even in their own half.
Balshaw needs to be tested in the air and moved around, but if Ireland overdo the kicking for territory, England will simply run it back rather than concede lineouts, and the danger therein is that Ireland will simply have to make too many tackles and, ultimately, unequal one-on-ones, such as Robinson v John Hayes, will occur and cracks will appear.
It would be disappointing if Ireland didn't rise to the huge sense of occasion and play well. But remembering how France put Ireland under pressure, England will probably put them under even more. And the nagging suspicion remains that, once again, England are due a big performance and Ireland are in line to provoke it.
Overall record: Played 116. England 69 wins, Ireland 39 wins, 8 draws.
Biggest wins: England 46-6 in 1997, Ireland 22-0 in 1947.
Highest scores: England 50-18 in 2000, Ireland 26-21 in 1974.
Five-game formguide: England W W W W W. Ireland W L L L W.
Betting (Paddy Powers): 1/20 England, 33/1 Draw, 8/1 Ireland. Handicap odds (= Ireland + 20 pts) 10/11 England, 16/1 Draw, 10/11 Ireland.
Forecast: England to win.
