Five things we learned from the NZ v AUS series

1) Aaron Finch will be captain at the World Cup

Selector George Bailey said as much during the series and the skipper dismissed any questions about his spot in the side with an eye-catching return to form. After a horror Big Bash campaign and two low scores to start the series, Finch's tour – maybe even his year – turned on the first ball he faced in the third game in Wellington, when a tight LBW call went his way. From there, he slammed scores of 69, 79no and 36 to become Australia's leading run-scorer in T20 cricket and the first Aussie to hit 100 sixes in his career, proving why he's such a valued and important member of the side.

2) The race to be the World Cup keeper is wide open

The identity of Australia's keeper-batsman for the World Cup, and where in the order he'll bat, remains a mystery. Both Matthew Wade and Josh Philippe showed positive signs in this series but neither were able to dominate the Kiwis, leaving the door open for the other to be the man in India, or for someone like Alex Carey or even Ben McDermott to jump ahead of them. And with David Warner and Steve Smith expected to come back into the side in India, whoever does take the gloves could find themselves batting further down the order, even though Wade and Philippe batted in the top three on this tour.

3) Australia's spin twins continue to go under the radar

After Ashton Agar made a slow start to the series, his first cricket in three months following a long injury lay-off, there were some suggestions that his place in the side might be in danger. But Australia's reigning T20 player of the year stormed back into the series, again forming a superb partnership with Adam Zampa that could be decisive later this year at a World Cup in spinning conditions. Since the start of last summer, Agar and Zampa have taken more T20 wickets than any spin pair in world cricket, combining for 48 wickets at an average of 19.62 and an economy rate of just 7.19, figures that ballooned out on Sunday when Martin Guptill got hold of Zampa in the series decider. They've also both shown an ability to bowl in the Powerplay in this series, giving captain Finch a versatility from his slow bowlers that Australia have lacked at previous T20 World Cups.

4) The third seamer's spot is up for grabs

Mitchell Starc and Pat Cummins are seemingly certain selections in the Australian XI for the World Cup, but the race for the third pace bowler's spot is wide open. Riley Meredith shot into contention with an exciting international debut against the Black Caps and while Jhye Richardson was unable to recapture his hot Big Bash form, he's another strong contender for a spot in the XI. Then there's Kane Richardson, who's been a reliable performer for the past 18 months, offers a point of difference to Starc and Cummins and is particularly effective at the death. The upcoming IPL could provide a few pointers ahead of the World Cup in India, with the two Richardsons, Meredith, Daniel Sams, Josh Hazlewood and Andrew Tye all hoping to impress, while Sean Abbott and Jason Behrendorff are also in the frame for a World Cup spot.

5) Australia still struggle against top quality spin

Ahead of a World Cup in India later this year, it would be of some concern for the Australians that while their spinners impressed with the ball, their batters struggled to negate the influence of New Zealand's slow bowlers. The Kiwi spin pair of Ish Sodhi and Mitchell Santner combined for 19 wickets in the series at an economy rate of just 7.36, while the frontline pace trio of Trent Boult, Tim Southee and an out-of-sorts Kyle Jamieson took 14 wickets at an economy of 9.11. The quicks are always likely to go at a higher rate given they bowl at the death, and Jamieson was well below his best in this series. But the impact of the Kiwi spinners would not have gone unnoticed, especially given World Cup conditions in India will be even more conducive to turn.

Qantas T20I tour of New Zealand 2021

Australia squad: Aaron Finch (c), Ashton Agar, Jason Behrendorff, Mitchell Marsh, Glenn Maxwell, Ben McDermott, Riley Meredith, Josh Philippe, Jhye Richardson, Kane Richardson, Daniel Sams, Tanveer Sangha, D'Arcy Short, Marcus Stoinis, Andrew Tye, Matthew Wade, Adam Zampa.

New Zealand squad: Kane Williamson (c), Hamish Bennett, Trent Boult, Mark Chapman, Devon Conway, Martin Guptill, Kyle Jamieson, Jimmy Neesham, Glenn Phillips, Mitchell Santner, Tim Seifert (wk), Ish Sodhi, Tim Southee.

1st T20: New Zealand won by 53 runs

2nd T20: New Zealand won by four runs

3rd T20: Australia won by 64 runs

4th T20: Australia won by 50 runs

5th T20: New Zealand won by seven wickets