Ireland's defeat to New Zealand on Saturday is probably the most devastating of their eight Rugby World Cup quarter-final losses, for this team was rated the best they had ever turned out at the sport's quadrennial showpiece.

The defeat ended not only their dreams of a first ever semi-final but also their winning run of 17 Tests and brought the curtain down on the careers of two outstanding players, Johnny Sexton and Keith Earls.

Others are likely to follow soon but once the pain eases and, as head coach Andy Farrell said, "we put a smile back on our faces", there are reasons for optimism that when the 2027 World Cup in Australia comes around the glass ceiling of the last eight will finally be shattered.

AFP Sport picks out three of those reasons:   

Farrell staying is key

"They are an incredible bunch led by the man beside me," said Sexton in his final post-match conference.

The man he was referring to was Farrell and he is pivotal to Ireland's future good health and their chances of being a contender for the next World Cup.

The 48-year-old Englishman has created an atmosphere of happiness and inclusiveness embracing all types of characters within the squad in stark contrast to his more disciplinarian predecessor Joe Schmidt.

This has transformed the Irish from a one-dimensional team into one that thinks on its feet, is allowed to express itself, but just came up against a tough-as-teak and clinical All Blacks side.  

"The way Faz leads us, no-one wants to leave. It's an incredible place to be," said Sexton.   

Farrell is contracted till 2025 and whether he remains may hinge on the new performance director, who is due to replace David Nucifora next year.

Sexton for one is confident Farrell can lead the side to even greater heights.

"It’s the best group I have ever been a part of. Bar none," said Sexton.

"These guys will go on and achieve great things."  

Crowley fit to fill Sexton's large boots

Sexton stayed on for the whole 80 minutes in what was his 118th and valedictory performance for Ireland. 

He may be 38 but overall his performances justified him staying on for one final hurrah.

The Irish have been blessed in having two outstanding playmakers this century -- Ronan O'Gara has been seamlessly followed by Sexton, but the question has always been who replaces the latter.

Several -- principally Joey Carbery, Billy Burns and Ross Byrne -- have tried to seize the mantle but have been found wanting.

However, out of the ashes of defeat and the crushing disappointment the successor to Sexton may have been found, even if he stayed sat on the bench on Saturday -- Jack Crowley.

The 23-year-old Munster fly-half has shone when he has come on in this World Cup with Byrne relegated to third choice.

When Crowley replaced Sexton both against Scotland and Romania he showed sublime creative skills with the vision required for a Test fly-half.

However, he also showed he has a cool head about him when he landed a penalty in the dying minutes against South Africa to stretch the lead to 13-8.

What really impressed was his awareness of running down the clock, leaving the Springboks less time to come back at the Irish.

"Jesus, what a hope for Irish rugby," O'Gara told Irish website 42.ie three years ago -- his prediction would seem spot on.

Schooled for success

Scotland head coach Gregor Townsend made the bold prediction in the wake of the 36-14 thrashing by the Irish that Ireland would dominate rugby for the next five to 10 years.

He based his opinion on a strong system of bringing players through.

"Their pro rugby system is very strong and they have got an age group system that's very strong," he said.

Leading the way in terms of churning out top-class players are the Leinster schools, although Munster is less oriented in that way.

Irish rugby great Tony Ward has seen the private school system up close having been director of rugby at St Gerard's.

The 69-year-old former dashing fly-half is in no doubt how integral it is to the future of the Irish national side.   

"The schools' importance to rugby at a higher level -- provincial and national -- is huge," he told AFP.

"It is the bedrock and has always been, and I think everyone accepts that.

"It is the best system in Europe."

pi/gj