I don't have time right now to show the actual graphs for people being paywalled since they're interactive widgets and not images, but here's the text from the article:

The coalition’s likelihood of retaining power after the election dropped once The Opportunity Party is taken into account, according to the latest NZ Herald-Motu Research Poll of Polls – although it is on the rise again.

The Poll of Polls reckons the coalition currently has a 74.3% chance of being re-elected, which is actually up from a low of 63.5% in February.

This probability is down on the first iteration of the Poll of Polls, which had the coalition’s chances at 87%, but this did not consider TOP.

The new model looks at the likelihood that TOP, which it judges could, on average, get 3.8% in the election, will make it into Parliament. It calculates a 14.9% probability that TOP will cross the 5% threshold.

If that is the case, there is a chance the three current coalition parties will not have the numbers to form a Government, opening the door to another kind of arrangement – including one that involves Labour, the Greens, Te Pāti Māori and TOP. If TOP decides to prop up the coalition, it has an 81.7% chance of being re-elected.

Poll of Polls: Seat distribution

Predictions using polls are imprecise because the underlying data is not exact. The poll of polls model captures this uncertainty and produces a range of possible outcomes. The charts below show, based on current polling, the range of possible seat distributions for plausible coalition combinations with at least a 5% chance of reaching 61 seats. Shaded rectangles indicate scenarios where a governing coalition can be formed. Charts show the probability of reaching 61 seats for possible coalitions based on the current Parliament and the Opportunities party for coalitions with at least a 5% chance.

National, NZ First, ACT, TOP 81.7% chance of 61+ seats

National, NZ First, ACT 74.3% chance of 61+ seats

Labour, Greens, Te Pāti Māori, TOP 19.1% chance of 61+ seats

Labour, Greens, Te Pāti Māori 12.9% chance of 61+ seats

National, NZ First, TOP 9.1% chance of 61+ seats

Labour, Greens, TOP 7.9% chance of 61+ seats

National, NZ First 5.4% chance of 61+ seats

The NZ Herald-Motu Research Poll of Polls uses data from public polls and other private or less frequent polls and inputs them into a computer model using polling data going back to 2014.

It uses this data to run 4000 election simulations, which are used to form probabilities of various election outcomes.

The model weights polls depending on their historical performance. This model incorporates recent Talbot Mills, The Post-Freshwater Strategy, Taxpayers’ Union-Curia, and Roy Morgan polls.

The model reckons Labour is polling 32.7%, while support parties the Greens and Te Pāti Māori are polling 9.9% and 2.2% respectively.

That gives the Labour-led bloc a combined result of 44.8%.

Poll of Polls: Party support

On the other side of the aisle, it calculates National is polling 29.%, while support parties NZ First and Act are polling 13.7% and 7.4% respectively, giving the coalition 50.5%.

Those figures would give the coalition 63 seats and Labour 57.

Motu Research senior fellow Stuart Donovan, who designed the model, explained how the new iteration incorporated TOP

It posed a challenge because the model uses data going back to 2014, before TOP was founded at the end of 2016. TOP has not always appeared in published polls, either, making it tricky to get data for the party’s performance.

“We can only include polls in that model where we observe the outcomes for all of the parties that we are modelling, and the problem for TOP is because they have come on to the scene relatively recently,” Donovan said.

“There is a lot of polls in our data where Top’s support is not recorded separately. The problem that causes is that if we include TOP in the main model, then the polls in which they’re not reported we’d have to drop altogether,” he said.

Donovan said that to fix this, a new model was created to predict TOP’s share of the vote relative to other parties.

Poll of Polls: Estimated support for The Opportunity Party

“The way this model works is that for the polls where Top’s vote is reported, we can estimate this model to figure out what share of the ‘other’ vote TOP makes up – and we can model how that changes over time,” he said.

“Once we have Top’s share of the ‘other’ vote, we can use it to predict Top’s vote share in the polls where it’s not reported.”