Big Picture
There will be more important T20 matches for these two sides to play later in the year, but a deciding contest to this series is a good opportunity for them to hone their skills in tournament-style play. Australia have been playing must-win for the last two matches, turning in impressive victories, and it feels as though while they have gathered confidence, it has ebbed away from New Zealand.
New Zealand's coach, Gary Stead, was reasonably blunt after the defeat on Friday in saying he thought his team took a backward step with the bat. There is limited scope for changes with the 13-man squad they have for this series so it would appear likely the same top order will go again, but there is pressure on Tim Seifert in what has been a disappointing series for him.
Spin can be expected to play another big role and Australia have deeper options available with the trio of Ashton Agar, Adam Zampa and Glenn Maxwell doing an outstanding job yesterday. Mitchell Santner and Ish Sodhi were also impressive, but it may be that Kane Wiliamson will have to use himself this time.
Straight after the match, Australia's squad will head to Wellington airport and board their charter flight back to Sydney. Those players from states with open borders to New Zealand (excluding Auckland) won't have to quarantine but those from places where regulations in place potentially face isolation depending on whether they go straight home.
This is the last confirmed international cricket Australia's men's team has on the schedule for some considerable time (barring an unlikely England comeback in the final Test against India) although there could be a mid-year white-ball tour of the Caribbean ahead of the final build-up to the T20 World Cup. For New Zealand, their home season will conclude later this month with ODI and T20I series against Bangladesh.
Form guide
(last five completed matches)
New Zealand LLWWL
Australia WWLLW
In the spotlight
The trickier the surface, the more a player like Kane Williamson can become important. A captain's innings could be what New Zealand need to overcome their batting struggles of the last two matches and Williamson's skill could follow the template laid by Aaron Finch in batting through an innings depending how early he gets to the crease. He could also have an important part to play with the ball - he has not bowled in a T20I since February 2018 but came close to bringing himself on in the last game and another spin option may be better suited than the pace of Kyle Jamieson.
While the spinners are likely to take centrestage, Kane Richardson's cutters also proved highly effect in the fourth match as he picked up 3 for 19. He is an often unheralded part of Australia's T20I side but before his home season was disrupted by opting out of the India series due to the restrictions of the biosecure bubble to stay with his family he had played 12 consecutive matches. He can be confident of a spot heading into the T20 World Cup even when other players return.
Team news
Having confirmed they won't draft another spin option into the squad there is a limit to what New Zealand can do. Jamieson has had a tough series and they could, at a stretch, consider replacing him with Mark Chapman and making up overs of spin from the part-timers but that is a risky option.
New Zealand (probable) 1 Martin Guptill, 2 Tim Seifert, 3 Kane Williamson (capt), 4 Devon Conway, 5 Glenn Phillips, 6 Jimmy Neesham, 7 Mitchell Santner, 8 Kyle Jamieson, 9 Tim Southee, 10 Ish Sodhi, 11 Trent Boult
D'Arcy Short, Ben McDermott, Andrew Tye, Jason Behrendorff and Tanveer Sangha have not seen any game time on the tour (Ashton Turner has already gone home for the birth of his child) but a winning combination could be given the chance to seal the series. Short's left-arm wristspin could come into the equation as much as his batting while the uncapped legspinner Sangha would be an exciting and brave option.
Australia (probable) 1 Aaron Finch, 2 Matthew Wade (wk), 3 Josh Philippe, 4 Glenn Maxwell, 5 Marcus Stoinis, 6 Mitchell Marsh, 7 Ashton Agar, 8 Jhye Richardson, 9 Kane Richardson, 10 Adam Zampa, 11 Riley Meredith
Pitch and conditions
While there was an expectation that the pitch would change, both sides were surprised by how it played on Friday. It won't have had any further use before the decider now the men's and women's matches have been switched so conditions are likely to be very similar. One concern is that the forecast for the morning in Wellington isn't brilliant with the chance of showers.
Stats and trivia
The 11 overs of spin bowled by Australia in the fourth match was their second-most in a T20I
Kyle Jamieson has conceded 175 in the series. The record is 187 held by Tim Southee although there remain a limited number of five-match series.
Quotes
"[Australia] adjusted very well, we were probably a bit slow to. But we know how the surface will play and it will probably be very similar. Spin and cutters were quite effective."
Mitchell Santner
"We were under the pump and it's a nice feeling now that we are back in this series."
Adam Zampa