Mike Ruddock believes the destiny of the Grand Slam will be shaped by the decision on whether or not to have the roof closed at the Principality Stadium tomorrow.
Leave it open and Ruddock considers the forecast wet conditions could just give Ireland – his resident homeland – enough of an edge to deny Wales a third Grand Slam of the Warren Gatland era.
Have it closed and the coach who masterminded the Slam of 2005 – the first for 27 years – thinks a faster game would tilt the contest in the home side’s favour.
The only trouble with Ruddock’s analysis from a Welsh perspective is that the final say is an open and shut case. It rests with Ireland and their head coach Joe Schmidt who has said he will make his call on Friday afternoon.
Gatland, as always in poor weather, wants to lock out the elements and has asked Schmidt to consider the greater good of the game as a spectacle. Yeah . . . sure, Warren.
Ruddock is currently back in Wales, and back in Mumbles, his base from where he plotted Ireland’s defeat 14 years ago. But his permanent residency remains Dublin where he has become the most successful coach at the top end of the Irish club game – delivering trophy after trophy for Lansdowne and player after player for Leinster and the national side.
But he does not need to close his eyes to recall his proudest day as a coach, a bright sunny afternoon in Cardiff when a strong Ireland side wilted under the fervor and expectation of a home nation, rather than under a closed roof.
“I can still remember every detail about the day, the occasion, the joy on people’s faces and even some of the celebrations afterwards,” he says.
“The players involved this time should savour it, too, although it might not come back to them for a while because they will be so wrapped up in the game.
“They were well-matched teams in 2005 and they are this time, but the passion and emotion of the day can be a huge strength for Wales if they are able to channel that in the right way.
“If the roof is closed, then the atmosphere will be retained in a real cauldron which will favour Wales, but it will help Wales in a rugby sense, also.
“The game is faster with a closed roof, you get the ball away from the breakdown a fraction of a second more quickly, which means the chances of Wales getting outside that Irish defence are improved.
“Wales have more players with flair and that creative X-factor – like Liam Williams and Josh Adams, who has been fantastic – and you want those players to get the ball in their hands at speed.
“But if it’s an open roof, then I think it slightly favours Ireland who will find it easier to control the game through a big, heavy pack. They can use their maul more effectively.”
To close or not to close. That has always been the question on big occasions when bad weather has been on the way, but World Rugby’s ruling has always been that both teams must agree to the button being pressed, otherwise the lid stays off.
Schmidt has claimed Wales have tried to get that ruling overturned by appealing directly to the Six Nations, but the final say is likely to remain with him.
It’s a protocol that has always stuck in Gatland’s craw. Home teams can decide the exact dimensions of their pitch – within margins – the cut of the grass and the water poured on beforehand, so why not the roof?
A better ruling might be for the match official to have the casting vote in the event of a split decision. That way, the referee could make the call purely on the conditions of the day – and whether they can be improved – rather than on matters of noise and atmosphere.
Either way, Ruddock reckons it’s a big call because it affects the tiny matters of crucial detail.
“Wet and blustery conditions affect the small details. You don’t get the ball away as early, you tend to hold the ball tighter in to your chest, and everything is slightly slowed down.
“That would favour Ireland and takes something away from Welsh flair, although I have to say I’ve been very impressed by the Welsh defence in this tournament so Ireland would have to spend a long time wearing it down.
“It took Ireland 35 minutes to do that against France in their last game and it might take them even longer this time. Ireland play through their pack, they get on the front foot and they over-power you.
“But it’s always a similar game plan and they can occasionally be predictable as happened against England.
“The difference tomorrow is that England were able to exploit that with a shrewd kicking game because Ireland had Robbie Henshaw at full-back.
“That probably seemed like a good idea at the time because Henshaw had played there before, but England recognized his positioning was a little off and they were able to turn and stretch him.
“This time, Rob Kearney is back, so I don’t see that being a problem for them.
“It’s going to be an arm wrestle, but I just hope the Welsh psyche for instinctiveness gives them that little spark to get them through.
“An open roof or a closed one, it’s going to be a tight game and a difficult one to call. All I know is that I made a lot of bets back at Lansdowne that Wales would win.
“If they lose, then I’ll be taking out a big bank loan to repay them all.”