Perhaps no team will experience as dramatic an overhaul heading into 2020 as France.
After coming within five minutes of a World Cup semi-final place, France will be looking to capitalise on a golden generation of young talent under a new coaching staff led by Fabien Galthié.
The former French skipper and scrum-half arrives with vast experience and an ambitious project to get Les Bleus back into the world’s top three teams.
To do so, he will be able to call upon players from the back-to-back World Rugby Under-20s champions, and a talented young core.
The good news for Galthié is that he got an early chance to see what this French team was capable of when he worked under Jacques Brunel during the World Cup campaign, linking up after the Guinness Six Nations.
Making the jump from assistant coach to head coach will be a challenge, but he, as well as new backs coach Laurent Labit and director of performance Thibault Giroud have all got a head start with their contributions in Japan.
Giroud may be one of the lesser known names among a star-studded coaching team that also features Shaun Edwards, but his role will be crucial for Galthié, who hopes to employ a very fast-paced game plan requiring optimum preparation.
The other new faces include former France hooker William Servat, who will be in charge of the forwards and the scrum in particular, having carried out a similar role with Top 14 champions Toulouse. Karim Ghezal arrives from Lyon to look after the lineout, while Labit is in charge of the backs after winning two French titles in conjunction with Laurent Travers, first at Castres, then at Racing 92.
Rounding out the coaching staff is Raphaël Ibanez, who will serve as team manager and played a large role in Edwards’ appointment.
The pair know each other well from their time together at Wasps, and the hope will be that Edwards can get France’s defence working like he did Wales during their three Grand Slam successes in 12 years.
He follows in the footsteps of another former rugby league coach, Dave Ellis, who worked with France under both Bernard Laporte and Marc Lièvremont as they won four Grand Slams and reached the 2011 World Cup final.
There will also be a change of captain, with Guilhem Guirado having called time on his international career at the end of the World Cup.
He, Sébastien Vahaamahina and Louis Picamoles are the three members of the World Cup squad to have called it a day after the tournament, with a number of options to replace Guirado as skipper.
Jefferson Poirot got his first taste of international captaincy this year, and at 27, has youth on his side.
Others who have been considered include back row Charles Ollivon, who made a remarkable return after three years out of the international game with injuries.
Finally Julien Marchand, the young Toulouse captain, is another who is in contention, although the 24-year-old has played down his chances, having made his Guinness Six Nations debut earlier this year.
Only Uruguay and Namibia took younger squads to Japan, so the overhaul of the French squad has already begun, and it is set to get even younger with Guirado and Picamoles no longer involved.
The likes of Antoine Dupont, Romain Ntamack and Damian Penaud are already established internationals with Penaud the oldest at just 23.
Ntamack impressed at fly-half this year, but could switch to inside centre with the return to full fitness of Bordeaux’s Matthieu Jalibert.
The 21-year-old made his international debut in the 2018 Championship before injury cut short his campaign in the opening game against Ireland. After a long rehabilitation, he has come back in stunning fashion for Bordeaux and looks primed to make an impact in February.
Baptiste Couilloud was another who got his first chance in 2018, and while a broken leg kept him out of action internationally in 2019, he should be back and pushing Dupont hard next spring.
The aforementioned Marchand and Toulouse teammate and back-rower François Cros are among the others with a couple of caps to their name but in line for greater opportunities.
And finally there is the generation which one successive world titles at junior level in 2018 and 2019. Ntamack, tighthead Demba Bamba and centre Pierre-Louis Barassi have already made the step-up to the highest level. They could soon be joined by second row Killian Geraci of Lyon, while hooker Maxime Lamothe, back-rower Cameron Woki and centre Arthur Vincent are among those pushing for inclusion.
Galthié will not have it easy in his first campaign in charge, opening up at home to World Cup runners-up England in Paris.
That game on Sunday February 2 will be a baptism of fire although France have won three of the last four meetings at the Stade de France.
A week later they host Italy before two tricky away trips, first to Grand Slam champions Wales, against whom France twice saw big leads slip in 2019, before heading to Edinburgh to take on Scotland.
Finally they will host Ireland on Super Saturday to round out the Championship.
Later in the year they will travel to Argentina to take on Los Pumas in a two-Test series, having edged them out in the World Cup pool match in Japan.
Their November schedule has yet to be confirmed, while in 2021 they will kick off their Guinness Six Nations campaign away in Italy.
By that point, we should have a much better idea of what to expect from Galthié and France. What is certain is that the raw materials are in place, both in terms of the coaching and playing personnel.