EVEN those on the opposing side of the referendum would have to admit, no matter how grudgingly, that it has been a good week for the Yes campaign.

Alex Salmond was clearly the winner of Monday's BBC debate with Alistair Darling, besting the former Chancellor on the currency question, and reducing him to a dry-mouthed stammer by asking which job-creation powers - if any "- would pass to Holyrood in the event of a No vote.

Although it occasionally turned scrappy, it never matched the nadir of Nicola Sturgeon and Johann Lamont's shouting match, and covered a wider range of issues than its STV predecessor. It was a good platform for the First Minister and he made the most of it.

Most commentators awarded the winner's medal to the First Minister, even if they went on to cast doubt over how important such debates are in attracting voters to either cause.

However, a Survation poll shortly afterwards indicated a four-point rise in support for a Yes vote among decided voters since the STV debate, to 47%. It remains to be seen whether other polls show a similar trend, but the debate can be banked as a solid win for the Yes campaign.

For those already exhausted activists knuckling down for the final, gruelling stretch, the psychological lift alone was invaluable. But the tide of events now running in Yes's favour is broader than just one debate.

Better Together's premature elation over Sir Ian Wood's oil estimates, is an example of the problems which are blunting their arguments.

Rather than convince voters that the North Sea is running dry, the exercise showed Sir Ian's 16 billion barrel figure to be just one estimate among many - indeed, as we reported last week, it was just one estimate of Sir Ian's among many, the oil tycoon having plumped for an upper limit of 24 billion not so long ago.

Rather than make Scots fret, the issue merely drew attention to the oil riches off shore. Voters heard 16 billion barrels if you vote Yes.

Even if the total is less than 24 billion - which remains arguable - it is still an almighty christening gift for a newborn nation.

Then there was Better Together's car crash political broadcast, The Woman Who Made Up Her Mind to vote No with a shrug, featuring almost every sexist cliché in the book.

It made Mad Men look daringly progressive.

As we report today, the No campaign's claim that the Scottish NHS is safer and most assuredly funded with devolution than under independence is also unravelling.

Day by day, bit by bit, the Unionists' arguments are looking shakier while the arguments for independence get more attractive.

It's tempting to sit back and watch the fun. As Napoleon said, "Never interrupt your enemy when he is making a mistake."

However, it would be foolish to assume that Better Together can mess it up indefinitely.

Beneath the veneer of incompetence, the No campaign remains capable of sharp manoeuvres.

Last week it wasted no time capitalising on the stupidity of a few people who harangued the Labour MP Jim Murphy and pelted him with eggs.

It was pathetic rather than sinister behaviour, but by suspending his tour of 100 towns in 100 days on safety grounds in response, Murphy adroitly secured the next day's headlines to claim it was indicative of Yes as a whole.

He used the actions of a rogue few to smear a movement built peacefully by thousands.

At this point in the referendum, after more than two years of campaigning, with the stakes so high and the end in sight, it is inevitable that passions are running high.

Of course at this stage we cannot know who caused the trouble at Murphy's meeting, nor their motives for doing so.

But anyone who is determined that Scotland will vote Yes, as we believe it should, must do everything in their power to avoid giving opponents any opportunity to portray Yes campaigners as a braying mob.

Better Together supporters, some of whom are also guilty of bad behaviour, must also bear the responsibility to avoid trouble.

One of the most stirring aspects of the referendum has been the wide public debate about what sort of country this should be.

Whatever the outcome in 18 days, there will be work to be done to make sure public engagement in politics does not fade away.