On Thursday the Conservative Party became the UK’s first governing party to win a by-election since 1982. The Labour Party, which had held Copeland’s Westminster seat since 1983, did manage to hang on to Stoke-on-Trent in another contest, but the Copeland result was historic.

The Tories beat Labour by 2,147 votes. A ‘safe’ Labour seat was lost, spelling another disappointment for leader Jeremy Corbyn and triggering more calls for him to resign.

But what if Copeland had been one of our 18 Northern Ireland Assembly constituencies which, come next Thursday’s election will offer five seats? The make-up of the constituency’s representation ahead of the poll might have been very different, nevermind the subsequent media headlines and potential consequences for Mr Corbyn’s leadership.

As opposed to the First Past The Post (FPTP) electoral system employed in the above Westminster by-elections, where voters put an X by the sole candidate they support, next week’s Assembly vote will work under Single Transferable Vote (STV). Here, we give our preferred candidate a number 1 preference, our second preferred candidate number 2, and so on.

Whereas the candidate with the most votes wins under FPTP, with STV a quota is set which candidates must reach to be deemed elected. To calculate this, we divide the total number of valid votes cast by the number of constituency seats; and, to this, we add 1.

The Conservatives won Copeland having received 13,748 votes. Labour won 11,601. But, had this been a five-seat Assembly constituency under STV the quota for election would have been 6,214.

Judging by the 2015 Westminster general election result in the Copeland constituency the Conservatives and Labour may have entered a STV by-election holding two seats each, at least. Both would have been confident, then, of at least holding on to what they had.

So, who might have won the fifth seat?

A first glance at Thursday’s voting figures might suggest that the final seat should have gone to either the Conservatives or Labour had they stood three candidates. In third and fourth place were the Lib Dems and UKIP with 2,252 votes and 2,025 respectively. But would either the Conservatives or Labour have chanced standing three?

In last May’s Assembly election we saw political parties standing three candidates in constituencies, hopeful of winning three seats but having to settle for just one; standing too many candidates split the party’s vote.

Had Copeland operated under STV, we can imagine that more voters would have been inclined to give Lib Dems or UKIP their first preferences, and second and third transfers both in 2015’s general election and in this by-election, thinking they stood a better chance of picking up a seat.

So, going into this election Labour and the Tories may have had two seats respectively, with fifth place always looking unpredictable.

Although Labour’s share of the vote fell in Copeland, a proportional electoral system in a Labour-friendly constituency may have prevented the dramatics that followed Thursday’s count.

What this comparison of constituency and electoral systems show is the importance of voting transfers here, of candidate and vote management by political parties: three things to look out for in next week’s Assembly poll.

Pens, calculators and sweepstakes at the ready, then!