How about those twin imposters, triumph and defeat disaster? The reaction to last night’s debate between Alex Salmond and Alistair Darling reveals as much as anything that happened in the debate itself. And the story it tells is that Darling won a handsome victory.

His performance was far from faultless. I don’t understand why he was so evidently discomfited by the idea of agreeing with David Cameron that Scotland could survive quite comfortably as an independent country. Nor was I impressed by his response to the question of what greater powers might be devolved to Scotland after a No vote. Mentioning road tax was a blunder.

But at least he did not talk about aliens.

At least Darling did not made a chump of himself in that fashion. For all that he received a terrible beating on questions about the currency and economic policy, Salmond’s greatest error came when he was given the change to cross-examine Darling and chose to use it to mock some Unionist hyperbole much of which, as Darling noted, ought not to be taken too seriously. By doing so, Salmond made himself look small. Worse, he made independence seem small.

If he recovered somewhat in the latter stages that recovery was both too little and too late to salvage the evening for the First Minister. He lost the rounds that dominated the debate.

Whining that “it’s our pound too” isn’t quite good enough. Perhaps a currency union could be agreed after independence but, as Darling pointed out, it would come with significant strings attached that would inevitably constrain the actual independence of an independent Scotland. To this Salmond had no good answer, largely because – however inconveniently – the facts and balance of probabilities are each against him.

Darling also  - and quite deliberately, I think – took aim at Salmond’s character. He all but asked if you would really be happy to buy a used car from this guy. What’s under the bonnet? All Salmond had was “a good line but not a convincing answer”. And when Darling said “I want you to do something difficult, I want you to contemplate the possibility you might be wrong” he made Salmond’s ineffable self-confidence seem a weakness, not a strength.

Of course the independence debate isn’t really about Salmond but Darling did his best to make it seem so knowing full well that the First Minister is a polarising figure. Discredit Salmond and you can discredit his cause too.

So it was good, hard stuff. Darling didn’t much care about seeming likeable. He was prepared – or acted as though he was so prepared – to risk appearing overly aggressive if that was what it took to bloody Salmond’s nose. The badger was transformed into a wolverine.

And, look, the Nats know they took a beating last night. It may not change many people’s minds but that’s a different matter. Pro-Yes journalists admitted it was a “bad night” for Salmond. Yes spinners were reduced to saying, hey, at least we got our arguments across. It really was that bad.

It’s been thin gruel for nationalists today. You can tell this from their silence (in many cases) or from the desperation of their tweeting (in some others).

Here’s Nicola Sturgeon, for instance tweeting that: THE key point from debate – ICM says that FM won big with undecided voters – 74% to 26% of those still undecided post debate.

Oh really? Yes, actually. But it turns out that this is based on a sample of just 22 voters (weighted to be 31 people). It is not statistically significant or credible. But this is the sturdiest straw at which the Nats clutch today.

The other Unicorn, again according to the Deputy First Minister, is that ICM’s snap poll shows the Yes vote increasing by 4% to 47%. Well, sure. Inconveniently, however, ICM say “this sample was pre-recruited on the basis of watching the debate and being willing to answer questions on it immediately after the debate ended. While we have ‘forced’ it via weighting to be representative of all Scots, it SHOULD NOT be seen as a normal vote intention poll as it is premised on a different population type i.e the profile and nature of Scots who watched the debate is different to a fully nationally representative sample of Scots.”

Also: it’s a poll of 500 people. Its margin of error is unavoidably greater than is usually the case in such things.

How much these debates change minds is a reasonable question to ask. For what it is worth, before the debate started ICM’s unweighted sample reported 180 Yes voters, 206 No voters and 49 people who did not know how they would vote. After the debate they found 189 Yes voters, 224 No voters and 22 don’t knows. 27 don’t knows shifted during the debate and 18 of them went to No while only 9 travelled to Yes.

With all the proper caveats about an unrepresentative sample and all the rest of it there is simply no credible way of spinning these numbers as being good for the Yes campaign. Indeed there is something desperate (if plucky!) about the attempt to do so.

Of course, your voting intention before the debate was the best predictor of whether you thought Darling or Salmond won this arm-wrestle. Most Yes voters thought Salmond won and most No voters thought Darling won. Even so, Yes voters were much more likely to concede that Darling won than No voters were to reckon Salmond had the best of the exchanges.

Still, the best news for Salmond is that he will probably win the next debate (presumed to be on the BBC later this month). Partly because expectations for him will have been lowered and partly because few people will expect Salmond to perform so poorly again or Darling so well. This, inevitably, will inform or colour people’s judgement.

I still don’t think the debate will have changed many minds but, look, if Salmond had thumped Darling you can be sure Yes voters would be shouting about the game-changing importance of last night’s events. But he didn’t and they aren’t. Which tells you all you need to know, really.

Tags: Alex Salmond, Alistair Darling, british politics, Scotland, Scottish independence, TV debates, Unionism