The 2017 General Election has a preliminary result.

The preliminary result is an unofficial count of all the ordinary votes cast at the election: votes cast on the day by people whose name appears on the printed electoral roll who voted at a voting booth designated for their electorate (including during advance voting)

The official count is still to happen. They're more careful with it, with a lot of cross-checking. The official count also includes the counting of special votes. Special votes are:

votes cast overseas;

votes cast by the telephone dictation servce;

votes cast on polling day by people voting at a voting place not desginated to serve their electorate;

votes cast by people who enrolled after the printed electoral roll was closed (including during advance voting);

votes cast by people on the unpublished roll; and

votes cast by people who think they’re enroled to vote, but aren’t (these votes don’t count).

This election there are a lot of special votes. The most ever. The Electoral Commission estimate is that there are 384,072 special votes, which is around 15% of the total.

Historically, the voting patterns of those who cast special votes differ from those who cast ordinary votes. Special votes in recent elections have tended to favour left-aligned parties. It is probably fair to assume that this general direction of special votes this will continue at this election. But with so many more special votes, whether it is fair to assume that the size of the effect will be similar is less clear.

That said, we don't have anything better to go one, so using the same rudimentary method I used last time (assuming the variance in special votes is the same size as it was at the 2014 election), along with the Electoral Commission’s estimate of the number of special votes at this election, I predict the following final result:

Preliminary Projected Vote share Seats Vote share Seats National 46.03% 58 44.86% 56 Labour 35.79% 45 36.55% 46 New Zealand First 7.51% 9 7.32% 9 The Greens 5.85% 7 6.32% 8 TOP 2.21% 0 2.35% 0 Maori Party 1.08% 0 1.12% 0 ACT 0.51% 1 0.51% 1

In 2014, National did 17% worse on special votes than they did with ordinary votes, while the Greens did 53% better. This was enough to see National lose one seat after special votes were counted, and the Greens to pick one up. Labour did 14% better on special votes in 2014, than they did with ordinary votes. This meant they closed the gap with National a little, but that wasn't enough for them to take a seat off another seat off them.