Andy Farrell has never been a head coach before, not in rugby league or rugby union, not in England or Ireland.
This will automatically bring an element of the unknown.
The defensive mastermind will have to come out from behind the curtain, a la The Wizard of Oz, to show what he can do with the ball, as well as without the ball.
There isn't a professional rugby player in Ireland worth his weight in salt that has a bad thing to say about Farrell.
He has a formidable presence, is a likeable leader, who knows how to work hard, coach hard and, ultimately, play hard.
In 11 months' time, the green baton will pass from Joe Schmidt to Farrell in what will be a new Ireland era.
There is logical speculation that Farrell could renew his England partnership with Stuart Lancaster in what would be a reversal of roles with Farrell out in front and Lancaster out on the pitch.
The suggestion Leo Cullen could be part of a ticket is way off the mark, as Leinster look to show last season wasn't a flash in the pan.
Before all of that takes place, there is the significant matter of a Six Nations and that World Cup in Japan to navigate.
Nevertheless, Farrell did take a glimpse into the future in a joint statement with Joe Schmidt yesterday.
"It is a privilege to be considered for such a prestigious role," he said.
"I have learned a lot from Joe over the past few seasons and I will continue to learn from him over the next year as the coaching group and players focus on competing in two huge tournaments in 2019."
In fairness, Schmidt has also had the decency and the care for Irish rugby to make an early decision and advocate the virtues of his right-hand-man.
"The coaches have been fantastic to work with and Andy has made a big impact since coming into the group," said Schmidt.
"His ability to lead and his understanding of the game will ensure that the group will continue to move forward."
There is concern that Ireland will not be able to sustain their current standing in the game that this will turn out to be the exception that proves the rule.
The 2018 World Rugby Coach of the Year has earned every accolade that has come his way.
He will leave Ireland in a healthy state.
Leinster scrum coach John Fogarty attended an Ireland session out in Carton House, on the outside looking in, paying specific attention to Farrell's work.
"He delivers unbelievably well and he's got huge presence," said the former hooker.
"He delivers really, really well in front of a group, really good in his presentations, to the point, clear, with a bit of emotion.
"It was impressive to watch."
Farrell's ability to connect emotionally is one of his strengths.
"There's instant buy-in," said Fogarty.
"The players do love him and speak really highly of him. He's got huge presence."