Result in 2016: SNP 9 seats (9 constituency, 0 list), Conservatives 5 seats (1 constituency, 4 list), Labour 2 seats (0 constituency, 2 list), LibDems 1 seat (0 constituency, 1 list)

TO appreciate just how thoroughly the transformation of Scottish politics has been since the start of devolution, consider this: at the time of the inaugural Holyrood election in 1999, the north east was considered the SNP’s only true “heartland”, and yet they won just six of the region’s 16 seats. That included a mere two constituency seats, which was two fewer than Labour, and one fewer than the Liberal Democrats. Two decades later, the north east has become the epicentre of a Tory comeback and is thus, relatively speaking, a possible Achilles heel for the SNP, but Nicola Sturgeon’s party can still expect to easily outstrip that 1999 showing. What was once held to be a stellar performance would now look fairly dismal.

In the mid-point along that journey came a sweet spot, before the Tory recovery began, when the north east was still fully plugged in to the Scotland-wide swing to the SNP. As the 2011 election approached it became clear that the SNP had a good chance of winning all, or almost all, of the region’s constituency seats – and that provided the initial impetus for what was to become an interminable debate between the proponents of “both votes SNP” and “gaming the system”. The latter approach hinged on the theory that the SNP would have “too many” constituency seats to win any list seats at all, that all SNP votes on the list would therefore be “wasted”, and that independence supporters could get more bang for their buck by switching tactically to the Greens on the list.

Ironically, though, the eventual 2011 result in the north east couldn’t have been a better advert for “both votes SNP”. The Greens failed to reach the de facto threshold for winning a list seat – which, to use the language of tactical voting advocates, meant that all Green votes had been “wasted”.

By contrast, the SNP unexpectedly took one list seat in spite of having won every single constituency in the region, meaning SNP list votes had succeeded in earning some additional pro-indy representation. That was possible because the voting system, in spite of the claims that are made about it, is a form of proportional representation, and it at least attempts to give each party the number of seats their share of the list vote warrants. Some people talk as if there’s an artificial “cap” on the seats each party can win, but in fact there’s nothing in theory to stop the SNP or any other party taking every constituency and every list seat in a region – provided they put up enough candidates and can somehow get close to 100% of the list vote.

READ MORE: Nicola Sturgeon responds to Alba Party: 'Elections are not games'

More realistically, an ANC-style vote share of 60-70% might yield two or three list seats in a region, even when every constituency seat has been captured. The fact that something is very difficult to achieve does not mean it’s impossible.

But the flip side of the coin is that if a large party’s list vote falls back in any given region, they will be entitled to fewer overall seats, and the voting system will therefore stop helping them. That’s basically why the SNP lost their list seat in the north east in 2016, in spite of the fact that they also lost one of their constituency seats (Aberdeenshire West) to the Conservatives.

It wasn’t that the system had suddenly started working differently, and it wasn’t that the 2011 outcome was some kind of freakish aberration that can never realistically be repeated. It was purely that the SNP’s vote on the north east list had dropped heavily from 52.7% to 44.7%. There’s no earthly reason why the SNP can’t win list seats in the north east again this year, provided one of two things happen: either a) their list vote goes back up, or b) they lose more constituency seats, thus ensuring they’ll be awarded list seats to keep them at the overall level of representation their support entitles them to.

But is that how it will pan out? It may be challenging for the SNP to bounce back to a 2011-style list vote share, simply because competition for pro-independence votes is now stiffer. Although the Greens are still waiting for their first list seat in the north east after five attempts, they’re likely once again to take at least a few percentage points on the list ballot, and this time they’ve been joined in the fray by Alex Salmond’s new Alba Party. There simply isn’t enough data yet to judge how well the Alba Party are likely to do, and speculative predictions range from “zero seats anywhere in Scotland” to “overtaking the Tories”.

But what we do know is that Salmond himself will be the lead candidate in the north east. He has a formidable electoral track record in the area, notwithstanding his sole failure in Gordon four years ago, which can probably be attributed largely to national trends. It’s fair to say that, even if Alba’s performance is at the lower end of expectations, Salmond’s presence should mean the north east is the region where they have the best chance of grabbing a list seat.

As for the possibility of constituency seats in the region changing hands, that certainly can’t be ruled out, given that two Westminster general elections have occurred since the last Holyrood vote, and both have seen big changes in the north east.

In retrospect, the SNP look extremely fortunate to have managed to hold the Scottish Parliament seat of Banffshire and Buchan Coast against the Davidson tide in 2016, because the equivalent Westminster constituency has now been won twice in a row by the Tories, and is regarded as the closest thing there is in Scotland to a Brexiteer hotbed. That’s where the greatest danger probably lies in this election, although on a very bad day the SNP could also potentially lose Aberdeen South & North Kincardine, Aberdeenshire East, Angus North & Mearns and Angus South.

On the other hand, on a good day they could grab Aberdeenshire West back. That means the number of constituency seats the SNP could plausibly end up with in the region ranges from four to 10, and the range for the Tories is zero to six. That in turn leaves a considerable degree of uncertainty over the destination of the list seats, which are distributed in such a way as to correct for any over-representation or under-representation in the constituencies.

One thing that does seem reasonably unlikely, though, is that Labour or the Liberal Democrats will regain any of their former constituency seats in the region.

That failure will leave them in line to pick up list seats instead – although in the case of the LibDems, they’ll want to recover from their dire 6% vote share from the last election, otherwise they could be in danger of going without any representation at all.

One obvious target for the Greens will be to simply out-poll the Lib Dems – the gap between the two parties in 2016 was just 1.1%, and if the Greens can edge ahead this time, that might in itself be enough to nick a seat.