Just how good are England?
That would see Eddie Jones's men take sole possession of a record they currently share with New Zealand, whose run of 18 straight wins – including their 2015 World Cup triumph – ended with a first-ever defeat to Ireland when the men in green triumphed 40-29 in Chicago in November.
So if England win at Lansdowne Road, will it make them better than the current All Blacks?
The general answer from most rugby pundits appears to be 'no' or at least 'not yet', a view that has much to do with a quirk of the fixture schedule that means England have not played New Zealand during their current winning streak.
"It is a great achievement and, like the All Blacks, England don't go away in games," former New Zealand captain Sean Fitzpatrick told the London Evening Standard last week.
"But it is very difficult to know how close England are to the All Blacks because they are not playing each other," added the former World Cup-winning hooker.
Meanwhile, Will Carling, the last England captain to preside over back-to-back Grand Slams in 1992, said the All Blacks had the edge
"They have got more world-class players and more intelligent players," Carling told the BBC, having seen England widely criticised for the way they struggled initially to deal with Italy's 'no-ruck' ploy at Twickenham this season.
Jones' team may still be some way off being the best England side there's ever been, never mind anything else.
In an era where being crowned world champions rather than remorseless consistency has become the acid test, the 2003 England team coached by Clive Woodward and captained by Martin Johnson, who got their hands on the World Cup trophy after seeing off an Australia side under Jones's guidance in a thrilling Sydney final, has become the Red Rose outfit by which others are judged.
It is this focus on the World Cup that means the fine South Africa side that won 17 Tests in a row from 1997 to 1998 is also often overlooked when the discussion about great teams takes place given that their run of success came between the Springboks' own World Cup triumph in 1995 and Australia being crowned world champions four years later.
But considering they were amateurs in an era where no one had contemplated a Rugby Union World Cup, the celebrated New Zealand team of the mid to late 1960s that won 17 Tests in a row is also worth recalling.
The fact it took them the best part of four years to compile that winning sequence is one indication of just how much has changed in the intervening decades.
One thing the present-day England side do have going for them is relative youth, with former England flank Peter Winterbottom telling the Guardian: "Given this side are so young… they could become the best England side ever."
Not that Australian coach Jones, who likened the praise he and his team received from New Zealand counterpart Steve Hansen as akin to being a "bit like Red Riding Hood and the wolf when the wolf comes dressed up as the grandmother," has been getting carried away.
"We haven't got anything to celebrate yet. It is all ahead of us," he said after England thrashed Scotland 61-21 at Twickenham last week – a match where their third of seven tries, a blisteringly precise move finished by wing Anthony Watson was labelled as "close as rugby gets to perfection" by former England flyhalf Stuart Barnes in The Times.
When Wales were enjoying their glory years in the 1970s, their stars often joked that if ever England, with all their wealth and playing numbers, got organised they would be dangerous.
Well under Jones, who took charge after England's first-round exit at their home World Cup in 2015, no one now disputes that they are indeed "dangerous" even if the debate about just how good they are will carry on for a while yet.
Agence France-Presse
