Andy Robinson didn't have much cause for cheer in the aftermath of Scotland's loss to France the weekend before last, but one question brought a smile to his face.

It concerned his Scottish back row – and, specifically, whether the triumvirate of John Barclay, Ross Rennie and Dave Denton was the most dynamic breakaway trio he had ever seen playing for Scotland.

"Oh no," the coach said wryly. "I played against Jeffrey, Calder and White."

Robinson's reference to the holy trinity of Scottish loose forward play was a lovely touch, but it also provided some useful historical perspective. It is all too easy to be caught in the moment, to be starry-eyed about the present day, to find yourself scattering superlatives that cannot stand up to scrutiny. Yet even with those allowances made, there is little doubt that we are now in the midst of a golden age of back-row play.

And not just in Scotland. Across the globe, the crop of players who wear the numbers six, seven or eight on their backs may never have been better than it is right now. The other day, Robinson hailed Ireland's Stephen Ferris, Sean O'Brien and Jamie Heaslip as the best in the world. It was a staggeringly bold claim given the competition they are up against.

Is Ferris really a better player than France captain Thierry Dusautoir? Not according to the International Rugby Board, who named the Frenchman their world player of the year last year. Is O'Brien, nominally an openside, really superior to Richie McCaw, Heinrich Brussow and Sam Warburton? And just how does Heaslip stack against the magnificent Sergio Parisse of Italy or the living legend that is France's Imanol Harinordoquy?

Tough calls all. But then, the world player of the year prize has been won by back rowers on five of the 11 occasions it has been handed out since its inception in 2001. Given the perception the judges have been desperate to widen the franchise – specifically, to favour backs and northern hemisphere players – it is an astonishing figure. In those years, almost 40% of nominees for the prize have been loose forwards.

But why? How has it happened? What factors have brought back row to the centre of the rugby stage?

Of course, that may be the wrong question to ask in those countries where loose forwards have been the main men all along. Every country has its signature position, and in New Zealand the No.7 shirt has long attracted levels of reverence more suited to papal vestments. Scotland and France have traditionally cherished their breakaway forwards as well.

But now they have become the stars of every show. And it is easy to see why when you consider how other parts of the game have become so formulaic. It used to be thought that the scrum was the key to the game, so it is another startling statistic that not one of the 59 players who have been up for the IRB award was a prop. Two hookers and three locks in the sum total of contenders draw from the front five.

Things aren't a lot different behind the scrum either. Defences have come to dominate, so the flashing wingers who would once have caught the eye have been rendered anonymous. The game-changing players are all in the back row now.

It helps, too, that the lawmakers – and, more importantly, the referees – have finally come up with a set of interpretations that allows the fair and equal contest for possession that is at the heart of rugby union. Dynamic, powerful players have been given licence to play to their strengths, but the pendulum has not swung so far as to rob the craftsmen and scavengers of the right to make thorough nuisances of themselves.

It is impossible, too, to ignore the evolutionary dimension. The back row is the place for the game's out-and-out athletes, and the accumulated knowledge and experience of the 17 years that have passed since rugby turned its back on amateurism have brought forward a better, fitter kind of player. And just as they have changed to suit the game, the game has changed to suit them too. In Test rugby today, the ball is in play almost twice as long as it was just 20 years ago.

But let's not ignore, or forget to celebrate, the fortuitous demographic blip that has brought this glut of eye-watering talent along right now. It is far too easy to over-analyse phenomena like these; the most significant part of the equation is that a host of fabulous players all happened to be born within a few years of each other. And we, the great unwashed but endlessly grateful rugby public, are the beneficiaries of that.

But so to Saturday, the Aviva Stadium, and a mouth-watering prospect. The Irish have no specialist openside; the Scots have no specialist blindside. It is an intriguing clash of styles.

Denton, for one, can't wait. "I can't tell you how much I'm looking forward to it," purred the Scotland No.8, a revelation in his three championship outings to date. "It's going to be incredible. Playing against the French back row last time was incredible – the world player of the year and the likes – and the Irish are going to be the same. They are three incredible players. But I think we're a really strong back row, a good unit, and we work well together, particularly as we've only been together for the last game, and I think we can match them up front."

The World's Best Back Row . . .

6 Blindside Flanker. Thierry Dusautoir (France)

The 30-year-old Toulouse player has been a virtual shoo-in for France since he made his debut six years ago. The general consensus after last year's World Cup final was that he had outplayed Richie McCaw, so it was no great surprise that Dusautoir was named world player of the year the following day. A man of enormous dignity as well as skill, Dusautoir was born in the Ivory Coast, He made his breakthrough for France at the 2007 World Cup, famously making 38 tackles (two more than all the All Blacks put together) in France's quarter-final win against New Zealand. However, he is a creative player as well and has scored six tries in 52 Tests.

7 Openside Flanker. Richie McCaw (New Zealand)

McCaw's great, great grandfather emigrated from Scotland in 1893, so we might call him the one who got away. A rugby phenomenon, he has been the world's outstanding player for the best part of a decade, winning the IRB player of the year award three times. McCaw is as close as any player has ever come to being a perpetual-motion machine, and has virtually defined what a great openside has to be. He first captained his country in 2004, aged 23, and has held the honour since 2006. He led the All Blacks to World Cup glory on home soil last year, but subsequently turned down the offer of a knighthood, saying it would be inappropriate while he was still active as a player.

No.8. Sergio Parisse (Italy)

We can only speculate what Parisse might have achieved had he played for any other country. With Italy, he has often seemed to be a one-man band, making up for the shortcomings of the side as a whole with his individual brilliance. Few backs, let alone forwards, can handle as well as Parisse. He is also a magnificent counter-attacker and lineout operator. Still aged just 28, he had 50 caps in the bag before he was 25, and the century should not be long in coming as he looks certain to carry on adding to the 86 he has now collected. Parisse remains the only Italian to be nominated for world player of the year.