As he ponders his selection strategy for next Saturday's clash with Tonga in Kilmarnock Vern Cotter, the Scotland coach, might reflect on the fact he would probably still be sipping pastis in the Clermont Ferrand sunshine had Andy Robinson got that part of the job right a couple of years ago.

Scotland's 15-21 loss to the Pacific islanders in Aberdeen in November 2012 was a nadir for Scottish rugby and the end of the road for Robinson. The Englishman did the honourable thing and resigned the following day.

In truth, Robinson had been something of a dead man walking for a number of weeks, but at the point of his going it suddenly became easier to remember the rich promise of his earlier days in the job and the optimism he fuelled by guiding the Scots to home wins against Australia and South Africa, and a historic Test series triumph in Argentina.

As Frank Hadden, Robinson's predecessor, made an equally bright start, guiding the side to three wins in the 2006 Six Nations, there is clearly an established pattern of new coaches having a rejuvenating effect on the national side.

Now the question for Cotter is how can he maintain the upwards trajectory and avoid the tailspins that happened under Robinson and Hadden? His team is playing with energy and enjoyment, with power and pace, but can he keep the spring in its step?

Only time will tell, but the time Cotter spent at Clermont provides grounds for optimism. The New Zealander did not just create a winning team and end their apparently aversion to silverware, he also changed the culture of the club. Previous coaches at the Stade Marcel Michelin had been quick-fixers, but Cotter built something more sustainable. The fact they are top of the French Top 14 table today is a reflection of his legacy.

Now, though, without daily control of his players, the task is more difficult. Over the past two weekends, in victory over Argentina and narrow defeat to the All Blacks, Scotland have played some wonderful, up-tempo rugby and it is realistic to expect more of the same against Tonga. But getting the team to carry that momentum into the Six Nations is the real challenge for the new coach.

Already, though, he has made strides with individual players. Only a few weeks ago, Rob Harley might have been considered the third-choice at blindside, but after another horse of a performance he has nailed the position down as his own. Greig Laidlaw is a sharper player and a more authoritative leader under Cotter. Richie Gray is back to his magnificent best.

Against all that, the truth of the matter is that they still lost to an All Blacks side that had been shorn of a host of first-choice players. A side, moreover, in which the two genuinely stellar names, Dan Carter and Richie McCaw, failed to live up to their billings. We should resist the inherent pessimism of saying that the Scots will never have a better chance to beat the New Zealanders than this, but the door will not be left so wide open for a long time.

Yet, the Scots played with courage and alacrity. If there is such a thing as an act of calculated bravado then Tommy Seymour's interception of McCaw's pass in the 11th minute was it, and it fully deserved the try that followed.

Victor Vito had opened the scoring for the All Blacks with a powerful solo try a couple of minutes earlier, but the Scots' resolute defence kept their line intact until Jeremy Thrush went over for the decisive score six minutes from the end.

How critical was Greig Laidlaw's missed penalty in the 69th minute? Shaun Maloney became a national hero when he curled a ball inside the left-hand post at Celtic Park on Friday, and Laidlaw might well have secured that status had he done the same at Murrayfield the following day. But the ball refused to turn and the remorse of the Scotland captain was clear as he held his head and stamped his foot in frustration.

A successful kick would have put the Scots one point ahead. Would they have been able to protect that lead? "We will never know that," Laidlaw shrugged. "Clearly, I'm frustrated. I take pride in my kicking and I'm disappointed. The kick was just on the right post, but it stayed there. It's unfortunate that it didn't come back in. I wish it had gone over, that's for sure."

With Mark Bennett already ruled out, and with a number of other players carrying knocks that will need further assessment, Cotter's selection for Tonga will be dictated by medical matters as much as anything else. In times past, the game might have allowed some scope for experimentation, but Tonga's 40-12 thrashing of the USA in Gloucester on Saturday should dissuade Cotter from getting too cute on that front.

In any case, the coach pointed out that another factor comes into play. "These guys would probably also like to put the jersey on next week," said Cotter of the players who faced New Zealand. "We will sit down and talk things through and make a decision, probably later in the week depending on how the players recover."

Laidlaw certainly wants to keep his place and keep the side going forward.

"We can't let it be a flash in the pan," he said. "We've got another big game next week and we have to put together an 80-minute performance."