World Cup glory will complete the jigsaw
For three years, Joe Schmidt has been patiently putting the pieces in place, and his World Cup jigsaw is nearly complete.
During his time in charge, the Ireland coach has rewritten the record books, and last week's historic win over the All Blacks was the latest piece of the puzzle.
Since the 2015 World Cup exit to Argentina, the coach has made key decisions and produced big performances that have contributed to building a unit capable of fulfilling its potential in Japan next year.
Whether it is through personnel appointments or selections, adjustments to the game-plan or a commitment to having three players for every position, Schmidt has been methodically investing his efforts into lasting success.
All that investment has put Ireland in a position of strength as they look to finish their most successful calendar year with an 11th win in 12 games against the United States tonight.
Piece by piece, Schmidt has been putting the World Cup strategy together, and the big picture is becoming clearer all the time.
1. Appointing Andy Farrell
At the end of the 2015 World Cup campaign, Les Kiss left the Ireland set-up for Ulster and Schmidt faced a key decision that would help shape the future direction of his team.
The defeat to Argentina in the quarter-final was an era's worst defensive effort, but that wasn't the only factor in the coach's call. He also wanted a figure whose presence would help fill the leadership void left by the imposing presence of retired captain Paul O'Connell.
At the time Andy Farrell was announced as the new man, the dual-code international was still reeling from his own World Cup woes with England.
Schmidt parked that issue and recognised that the 2013 Lions defence coach would be an asset in so many ways. He was willing to wait until his gardening leaves was up for the right man to come in.
The results speak for themselves and Farrell is now seen as a natural successor to replace his boss should he choose to leave next year.
2. Beating the Springboks with 14 men
Having been forced to sit out the 2016 Six Nations as he was on gardening leave, Farrell's first involvement with the team came in Cape Town where Ireland were without a host of leading men, including Johnny Sexton.
Their absence was compounded by CJ Stander's first-half red card, but the team rallied to produce a superb performance to beat the Springboks away from home for the first time.
A week later, Schmidt heavily rotated the team and they couldn't hold on to their lead in Johannesburg, before coming up just short in game three in Port Elizabeth.
But, having created history and blooded a new generation of players, the coach had taken the first definitive on-field step towards 2019.
3. Blooding the 2016 U-20s
While the senior side were duelling with the Springboks, Nigel Carolan's Under-20s were on the march to the World Cup final and, while his focus was on the Test series, Schmidt had an eye on events in Manchester.
Victory over New Zealand was the highlight for a team bursting with talent, who lost the final to hosts England.
The head coach was clearly impressed and, by the end of 2017, he'd fast-tracked captain James Ryan, prop Andrew Porter and winger Jacob Stockdale into his squad.
Previously, young players were made to wait for their chance, but that trio - and Jordan Larmour, who is a year younger -have all become important players ahead of schedule.
4. Slaying the All Blacks
Before the young guns were introduced, Ireland followed up their win over South Africa with another piece of history as they claimed their first win over the All Blacks in 111 years of trying at Soldier Field.
This five-try success in Chicago was built on a new-found Irish mentality to take the game to the world champions for 80 minutes, keeping the ball in hand and playing with pace and intent.
New Zealand came back and won with a brutal performance two weeks later, but Schmidt's side had made an important statement about their intentions as they learned they could live with the best.
5. Halting the Chariot
On the back of that win, the 2017 Six Nations was a disappointing campaign with losses in Edinburgh and Cardiff derailing a tilt at the title.
England had already won the trophy for the second successive year when they arrived in Dublin and, at the time, Eddie Jones appeared to have built an unstoppable juggernaut.
Defeat to a superb Irish performance punctured that image and the Australian has struggled to recapture the lost momentum.
Ireland lost Jamie Heaslip to an injury in the warm-up but, led by Peter O'Mahony, they dismantled England's lineout and produced a display of real intensity and quality to stop the Chariot's march. Ireland have lost only once since.
6. Building depth in Japan
While his big men were on the Lions tour, Schmidt took a shadow squad to the United States and Japan, capping a number of young guns and giving a host of fringe players a taste of the World Cup host nation.
If he comes on today, Sammy Arnold will become the 37th player to win his first Ireland cap during this World Cup cycle. Schmidt has cast his net wide and, while some options have come and gone, he has been determined to offer chances and learn more about all of his options.
The Japan tour was a key point in the team's development, and when the Lions returned they had a couple of new teammates to get to know.
The investment in the team's strength in depth has resulted in being able to put third choice openside Josh van der Flier into the team and barely batting an eyelid against the best team in the world.
7. Evolving the style of play
As well as deepening the squad, Schmidt has been determined to transform Ireland into a more dangerous attacking outfit who are so comfortable on the ball they can suffocate the opposition.
Since the 2015 World Cup, the team has become more discerning with its use of the boot and less conservative when it comes to kickable penalties - often going for the jugular.
Jared Payne added a second play-making option until he was forced to retire and Garry Ringrose now takes the pressure off Sexton, while the forwards are all more than comfortable on the ball.
8. Winning the Grand Slam
Confidence levels built through a successful November 2017 and into a remarkable 2018 Six Nations campaign.
Ireland's refusal to lose in Paris was embodied by Johnny Sexton's drop-goal, and they reserved their best performance of the era for the finale in Twickenham where the already crowned champions wiped the floor with Jones' England.
With Stockdale scoring for fun and Ryan and Dan Leavy offering such energy and physicality, Ireland proved their mettle when the chops were down.
9. Developing new leaders
All the while, Schmidt has been working on the leadership group around Rory Best.
Johnny Sexton and Peter O'Mahony have been named as vice-captains, while Conor Murray, Keith Earls, CJ Stander and Devin Toner are among the other decision-makers whose opinions are valued within the set-up.
Despite the retirement of senior figures like Payne and Jamie Heaslip, the coach has trusted his leaders in his "player-driven environment" to drive standards on the pitch.
10. Winning the series in Australia
When Best was withdrawn on the eve of the tour of Australia, O'Mahony and Sexton stepped in to lead the side to a successful series.
One-nil down after the opening defeat, in which Schmidt gave Joey Carbery a go in the No.10 shirt, the tourists bounced back to win in Melbourne and Sydney and celebrate a famous triumph.
At the end of a long season, it confirmed Ireland's trajectory and put the disappointment of the South Africa tour to bed.
11. Beating the All Blacks at home
Last week, Schmidt and his team put to bed one of the last great Irish taboos by beating the All Blacks at home for the first time.
The 16-9 win was another feather in the coach's cap, and the scary thing for Ireland's rivals is they can get better and should have won by more.
Indeed, they did it without injured quartet Conor Murray, Seán O'Brien, Dan Leavy and Robbie Henshaw.
While it didn't put them on top of the world rankings, All Blacks coach Steve Hansen insisted that Ireland are now the top team in the world going into 2019.
12. World Cup success
Having achieved all that they have, Schmidt and Ireland will turn their focus to Japan.
No Irish team has gotten past the quarter-finals, but this side look best placed to break through the glass ceiling and will travel with realistic ambitions of winning the tournament outright.
Schmidt has steadily built a team and a squad capable of beating the best, now the final piece in the puzzle is to go to Japan and succeed by going far beyond where any Irish team has gone before in the Land of the Rising Sun.
Bring it on.