It all goes back to Brian Kerr and the Faroe Islands.
Just six years ago, Wales sat side by side with the Faroes in the FIFA world rankings, remarkably rated joint 112th in the world. Both sides were battling for the final spot in Pot 5 for the 2014 World Cup qualifying draw with dreaded Pot 6 waiting for the unfortunate nation.
Wales were set to be handed that final place, but some clever calculations caused an intervention and FIFA were forced to act.
"My ambition was to get the Faroes out of the bottom pot," reminisced Kerr, speaking to RTÉ Sport about his time in charge, when he guided the Faroe Islands to their four-point tally in the Euro 2012 qualifying group, including a 2-0 defeat to Estonia and a 1-1 draw with Northern Ireland.
"It was between us and Wales for the last place in Pot five and six. "And there was a lot of Faroese fellas working out the calculations and coefficients telling me that it was between us and Wales."
As it turned out, a Faroese political science student, Jakup Emil Hansen, worked out that his nation should be 0.07 points ahead of Wales and, as a result, FIFA were forced to back-track and granted Kerr his ambition with a place in Pot 5, relegating Gary Speed’s Wales into Pot 6.
"It was only when we spoke to Brian Kerr and told him about it, that things started to move quickly," said Hansen, speaking to The Daily Telegraph back in 2011.
"He has a lot of contacts in international football and in the international media, and once the story got picked up, we knew something had to happen because my calculations were right."
The rest, as they say… And within a few years Wales found themselves rocketing up the rankings, breaking into the FIFA Top 10, which led them to becoming top seed for the current qualifying campaign.
Wales took a good look at the FIFA calculation process and decided against playing non-competitive friendly games, where even victories could damage your FIFA ranking – Romania another top seed for these World Cup qualifiers - did something similar, while teams like England, Italy and France’s rankings have been damaged by playing friendly matches.
"This is as big as anything we’ve been involved in"
So if that decision proved the catalyst to kick off this "Golden Era" of Welsh football, current coach Coleman certainly brought them to the next level following the ground work of Speed, resulting in qualification for Euro 2016, which culminated in a narrow semi-final defeat to eventual champions Portugal.
"Up until two years ago, we’d never been anywhere near it, but now we are," said Coleman, speaking at the pre-match press conference in Cardiff. "We’re absolutely looking forward to a great game and it will be a fantastic atmosphere. There’s nothing to fear or to worry about.
"This is as big as anything we’ve been involved in.
Every draw meant the next game was "a must win" - Chris Coleman sums up Wales' campaign so far pic.twitter.com/BU2pJNUZ3W
— RTÉ Soccer (@RTEsoccer) October 8, 2017
"The good thing about it is we’ve been here before, so we’ve got that experience. "We’ve got to contain our excitement. We’ve always wanted to be in these big games where all eyes are on you and there’s so much to play for."
Wales are attempting to qualify for the World Cup for the first time since 1958 but instead of matching that feat, Coleman remains much more focused on the present and prefers to allow this current crop of players to make their own history.
"Whatever we’ve done, that’s not going to help us tonight"
"It is a golden era because they proved that.
"They were labelled this golden bunch of players before we qualified and I fought against that because they hadn’t earned that tag, but they’ve earned it now.
"This group of players have made the difference and they’ve gone one step further than anybody else that has gone before them.
"Whatever we’ve done [in the past], that’s not going to help us tonight."
And Coleman believes that he has the players to reach Russia next summer and has such belief in his system, or systems as the case may be, that even the absence of Gareth Bale could not put a dent in his upbeat approach to the must-win encounter.
"Someone said Wales are ten men behind the ball and Bale up front. I think that’s a lazy comment from someone who tactically doesn’t know too much about football.
"Even when he’s in the team, we don’t play with one set system, because we can’t afford to be flippant enough to think we’re that good.
"We look at the opposition, we get a game-plan and that changes, whether he’s in the team or not.
"When you’ve got someone that good, you’d be stupid not to come up with one that suits him, but it also has to suit everybody else.
"I’d much prefer to be planning with him than planning without him."
Coleman’s confidence and composure at the press conference, coupled with the jovial line of questioning from the local media, which included questions about a post-match party and whether or not the manager would break out the guitar, would suggest that many in Wales are perhaps looking beyond tonight’s game and planning for the play-offs, or even gaining automatic qualification should Serbia slip up against Georgia tonight.
Coleman, however, proved very generous with his time and was more than happy to answer any question thrown at him, speaking at length to the Irish media, which prompted the obvious line about his own Dublin connections and whether they would cross his mind going into tonight’s game.
"I won’t be thinking about how much I like Dublin and I won’t be thinking about the fact my Dad’s Irish.
"I’ll be thinking that I’m from Swansea and I’m representing Wales. You lot are in the way of what we need and I’ve got to try and somehow get past that.
"My Dad’s a Dublin boy. Of course the connections are always going to be there. I spent so much time in Ireland and I’ve still got family in Dublin.
"We’re going head-to-head with the Republic of Ireland and if it’s not us and it’s the Republic… of course I want it to be us, 100 per cent, but it would be nice to see another home nation at the World Cup."
After 6 years of maths, the equation is simple - lose and the dream is over.
