Two ballots and a 5 per cent threshold: how New Zealand's mixed-member proportional system fills Parliament

Background

New Zealand votes in a general election on 7 November, and smaller parties may decide who governs.
The country elects its Parliament every three years under the mixed-member proportional (MMP) system.
Each voter casts two ballots: one for a local electorate candidate and one for a party.
Winners in the 71 electorates take their seats directly; seven electorates are reserved for Maori, New Zealand's Indigenous people.
The party vote decides each party's overall share, and about 49 list seats are added so that seats match votes.
A party needs 5 percent of the party vote or one electorate win to qualify, and 61 seats is usually a majority in the 120-seat Parliament.