SCOTLAND’S Six Nations season so far, if judged solely by results, looks like the stereotypical rollercoaster: win, loss, win. Put some flesh on those bare bones by assessing the performances, however, and it becomes clear that substantial and lasting progress has been made.

The 27-22 result against the Irish was Scotland’s first win in the opening round of the Championship in 11 years. The 29-13 triumph two days ago was their first defeat of Wales for a decade. If they record an even bigger first in 12 days’ time at Twickenham – where they last tasted victory in 1983 – they will go into the final match against Italy with the Triple Crown in the bag, and knowing that the title itself could be theirs.

We are getting ahead of ourselves there, of course, but the manner of Saturday’s win and the circumstances in which it was played certainly encourage an optimistic outlook. Having been deprived of first-choice props Alasdair Dickinson and WP Nel before the tournament and suffered in the scrums as a consequence, Scotland went into the Wales game without Greig Laidlaw, their captain, place-kicker and scrum-half. A degree of self-doubt would have been understandable given how influential Laidlaw has become, but instead, ably led by John Barclay, the team showed an unwavering belief in their own principles.

The key raw ingredient of innate talent has been there for some time, above all in the most gifted individuals such as Stuart Hogg and Finn Russell. What has made the difference this season, besides the simple accumulation of experience, is the ability to make the most of that talent.

The fact that this is Cotter’s last campaign in charge may have something to do with the extra exuberance shown by the players over the last few weeks. But perhaps the most important catalyst has been assistant coach Jason O’Halloran, who has significantly sharpened an attack which previously produced an abundance of impressive build-up work without always being able to finish moves off.

Scotland were clinical, the Welsh coach Rob Howley and captain Alun Wyn Jones admitted after the game, and the same verdict was delivered after the Ireland win too. Clinical: in the past that was the adjective you would least associate with a Scotland performance.

Stamina is the other key ingredient this season: not so much physical, because this squad has never been short of fitness, but psychological. Scotland stick to their guns these days: if they fall behind they do not panic; if one attack is repulsed they go again.

The first half was a mundane affair, giving little hint of the drama to come. Russell and Leigh Halfpenny exchanged penalties, before Wales took the lead all too easily with what would turn out to be their only try. Rhys Webb took a quick free-kick from a scrum offence, and with the defence having been drawn infield, Liam Williams had just enough space to touch down in the left corner. The winger was rightly denied another score when Webb was penalised for obstructing Tommy Seymour, but Wales maintained the upper hand and led 13-9 at the break.

Scotland, though, began the second half in determined fashion, and went ahead within four minutes when Hogg delayed a pass superbly to put Tommy Seymour in. Russell converted, soon added another penalty, and then Tim Visser denied Webb a try with a brilliant last-ditch tackle.

That was the last we saw of Wales as a serious attacking threat, and with a dozen minutes to play Visser turned from try-denier to scorer, Hogg again providing the scoring pass. Russell converted to put the issue almost beyond doubt, then added a penalty just to make sure – and take Scotland’s second-half tally to 20 unanswered points.

It was a display of remarkable maturity from the home team, particularly bearing in mind the absences of some of the most senior members of the squad. Twickenham will be tough, all right, but on this evidence it cannot come soon enough.