I LOVE opinion polls. I love the way they go up tiddly up up and down tiddly down down and I love it when they’re wrong and I especially love it when they’re the same as my opinions so I can say: told you! But don’t you find them frustrating too? Don’t you sometimes look at the polls and think: who are these people?

Take the latest surveys on independence. There have been several in a row now which show a lead for Yes and supporters have declared it a historic moment similar to the historic moment two years ago when Yes was also ahead for several polls in a row. As I say: up tiddly up up and down tiddly down down.

But let’s be fair: it’s clear that support for independence has increased, possibly driven by the Supreme Court ruling on referendums. Which appears to suggest there’s a certain voter who says “grrr, the Tories; grrr, Brexit; grrr, the Supreme Court, I’m voting Yes” before changing their mind again when things settle down. In other words: we’ve been here before.

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The best phrase to describe this kind of voter might be Angry Switherer, although how many there are is unclear. Just look at the polls and you’ll see that Scottish politics is still in the shadow of the two monoliths: 40% or so who support Yes and something similar for No. In between the two, you do get Mr and Mrs Angry Switherer, but the effect they have is relatively small.

More significant, I think, are three other types of voter, who you can also see lurking in the polls, and the first of them is pretty influential. It’s essentially the kind of Scot who prioritises the Union and is willing to support whichever party he or she thinks has the best chance of beating the SNP. You could call them The Unionist Switcher.

What’s interesting with them is that the polls showing a lead for Yes also show what the Switchers have been up to. Asked about a general election, more voters are supporting Labour and much of this will be because the Unionist Switchers have judged Labour is now their best choice in the way they used to think it was the Tories. Obviously, there will be some Lib Dems and SNP supporters moving to Labour too, but the unionist switching is what’s driving a lot of it.

Also significant in the polls is a related but different type of voter whose behaviour you can spot in the polls for Holyrood. Here, there’s significantly more support for the SNP than for Westminster and part of that’s down to the Scots who live an apparently oxymoronic existence as Unionist SNP Voters. Essentially, these are people who are likely to vote No but don’t mind voting SNP at Holyrood because they think it’s the best option. It was something you saw big-time with Brexit.

Which leads to the last – and possibly most influential – type of voter who can be a bit harder to spot in the polls. As I said, there’s probably been an increase in support for independence. But Yes or No is only in the lead if you take the don’t-knows out and, as we’ve learned before, that can be a pretty dodgy thing to do.

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So, the question we need to ask is who exactly the don’t-knows are and a large proportion of them are likely to be the fourth type of voter: The Shy No. We know this is a thing in polls: the shy Tory or shy Republican, someone who knows how they’re going to vote but doesn’t tell the pollsters. It says a lot about Scottish politics that No voters might feel this way, but if it’s true, you can count a lot of those Don’t-knows as Nos.

Of course, some voters will belong to several of these categories at different times. But perhaps what we can really read from the polls isn’t some big switch to Yes but a sign of where politics is more broadly. Lots of voters know what they’ll do and are unlikely to change. But our fate is actually in the hands of a smaller number who’ve learned to live and thrive in the nuanced and complicated world of Scottish politics. They are the voters who are willing to move. And move again.