You really had to be there to see it.

Or, rather, to see that it wasn't there. Even in his darkest moments, and there have been a few down the years, there was always a glint of steely defiance in Andy Robinson's eye, but on Saturday evening it was gone. Now, slope-shouldered, as he sat in the small press room at Pittodrie, he looked a haunted man. No glint, no steel, no defiance any more.

Paul Ackford, an England team-mate of Robinson's before he became a perceptive columnist for the Sunday Telegraph, wrote recently of the time, towards the end of 2006, when Robinson's hold on the England coaching job was slipping.

Among senior club figures, he became known as "dead man walking". His authority damaged beyond repair; nobody believed he would hold the job much longer.

So at least there was something mercifully swift about the ending of Robinson's reign as Scotland coach, a welcome contrast to the slow, lingering death of six years ago.

What his body language told us on Saturday evening was duly confirmed yesterday morning in a terse Scottish Rugby Union statement.

"Andy Robinson has decided to step down from the role of head coach," it began. Nothing after that really mattered.

So sic transit gloria Andy, not that gloria was helping him out much at the end. Neither was anyone else for that matter. Those silly feast-or-famine critics who had spent three oleaginous years fawning over Robinson turned swiftly and cynically against him towards the end of his time in charge. Robinson, a decent and open man, possibly too decent and open for the scheming, Machiavellian, turncoat world in which he operates, looked horribly isolated by the end.

So the king is dead. Long live, er, the next bloke. Off we go again on that Sisyphean journey that starts with praising a new coach to the rafters and ends with calling for his head. The timescale is not quite fixed, but the entire process generally lasts between two and four years. Ian McGeechan was at the upper end of the range; Matt Williams, unsurprisingly, near the bottom.

But as it all kicks off again, I have this nagging doubt that we media types are complicit in creating a myth. We fuel the bonfires of coaching vanities by hailing this fellow and damning that one, but do any of us really know for sure that one is really better than the other?

We anoint these coaches as the game's shamen, the rugby rainmakers, but are we crediting them with powers that none of them really has?

The questions arise because even the most cursory glance down the list of names of those coaches who are routinely touted as the gurus of the age reveals a cast of characters whose skills have been doggedly resistant to any attempt to transplant them from one rugby arena to another. Or, to put it another way, there are a lot of one-trick ponies out there.

The smartest of them have rested on their laurels, perhaps quietly aware that their talents were particularly suited to one place, one team, one particularly fortuitous moment in history. Others, however, have put their reputations on the line, and few of those reputations have been burnished by the experience.

Think, for instance, of Bob Dwyer, feted for his masterminding of Australia's successful World Cup campaign in 1991, but disastrous in the context of English club rugby.

Or Marcelo Loffreda, whose career followed a similar trajectory as he took Argentina to third place in the 2007 World Cup but was sacked after one brief and unhappy season in charge at Leicester.

What, too, of Clive Woodward? Feted and ennobled after England won the 2003 World Cup, Woodward spent the next few years on a hubristic journey round other sports, seemingly oblivious to the fact that his skills were clearly not of the transferrable variety as he stumbled from one calamity to the next.

And Nick Mallett – already touted as a contender for the Scotland job – who was brilliant with South Africa but seemingly incapable of making a difference in his four seasons at Italy's helm.

All of which – and there are a number of other examples below those lofty levels – fuels a troubling suspicion that, frankly, coaches maybe aren't so important after all.

Moreover, their experiences suggest that getting the right man in the right place at the right time might be more a matter of luck than judgment.

What if there is no such thing, in objective terms, as a good coach? What if a coach's worth is only ever relative to the situation in which he is put?

But successful rugby teams do not happen by accident. And if it's not the work of the coach then who else should get the credit? Could we perchance be justified in pressing the rugby rewind button here and looking instead at the captain?

It's clear, from the examples above, that World Cup-winning coaches have been unable to thrive in other environments.

But what of World Cup-winning captains? In chronological order, the list to date, from 1987 to 2011, reads: David Kirk, Nick Farr-Jones, Francois Pienaar, John Eales, Martin Johnson, John Smit and Richie McCaw. A gallery of rugby giants, every one of whom imposed – far more than their respective coaches did – their indomitable wills upon the players they led.

In short, great teams appear to be made in the image of their captains, not their coaches. And maybe that's where Robinson really got it wrong as it fell to him to choose the Scotland leader.

The most common, and valid, criticism of Robinson was that he was an inconsistent and muddled selector. That trait was most starkly obvious in the way he chopped and changed between one captain and another. Robinson used six different captains during his time in charge: Chris Cusiter, Mike Blair, Rory Lawson, Al Kellock, Ross Ford and Kelly Brown.

In three consecutive and critical matches – the final two games of last year's World Cup and this year's RBS 6 Nations opener against England – he gave the armband to three different players. Can you think of a half-decent team in history that has ever done anything like that?

Maybe Robinson was just unlucky. Maybe it was the fault of the players that not one of them stood head and shoulders above the rest and made the job their own. Maybe Scotland will struggle until someone does emerge.

By which time, of course, Robinson will be long gone.