India need to win by at least a 2-1 margin.
For England to qualify, they have to win the series against India by a 3-1, 3-0 or 4-0 margin.
Australia would make it if the series is drawn - or if England win 1-0, 2-0 or 2-1, or if India win 1-0.
New Zealand won't go into the final cold. Last week it was announced they will play two tests against England at the start of June which happen to be scheduled in the two weeks leading up to the World Test Championship final, giving them vital preparation in local conditions.
New Zealand are currently unbeaten in an unprecedented 17 tests at home - they are also on a record streak of six consecutive test wins.
Reaching the final continues a remarkable run for the Black Caps across cricket's three formats since breaking their semifinal duck in 2015 to reach the Cricket World Cup final.
They were defeated by co-hosts Australia at the MCG in the final.
Four years later, New Zealand reached the Cricket World Cup final for a second straight time only to be denied in a Super Over defeat to hosts England, with the final decided on boundary countback.
In the test arena the turnaround has been remarkable.
In 2013, New Zealand were rolled for just 45, their third lowest total, in 19.2 overs, against South Africa in Cape Town. Only Williamson made double figures as New Zealand hit rock bottom.
At the time, the Black Caps slipped to eighth in the world test rankings - their worst ever ranking.
Following their clean sweep of West Indies and Pakistan this summer, the side reached the pinnacle of test cricket's world rankings for the first time.
New Zealand are unbeaten on home soil over the past three years; their last loss coming in March 2017 against South Africa in Wellington.
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Since Williamson took over as captain from Brendon McCullum, who led the 2015 World Cup run, the Black Caps have won 21 of 35 tests, with another victory this summer under Tom Latham. Williamson's winning percentage as captain sits at 60 percent, easily the highest for a New Zealand test skipper, with the next best Geoff Howarth at 36.6 percent.
Williamson, Henry Nicholls, Tom Latham, Trent Boult, Tim Southee, Ross Taylor, Mitchell Santner, Colin de Grandhomme and Matt Henry are all a chance to appear in a World Cup final and a World Test Championship final.
"Unacceptable risk"
Interim Cricket Australia chief executive Nick Hockley issued a statement late Tuesday saying he believed there was no choice but to postpone the tour and he had informed his South African counterparts.
"Due to the public health situation in South Africa, which includes a second wave and new variant of the virus, and following extensive due diligence with medical experts, it has become clear that traveling from Australia to South Africa poses an unacceptable level of health and safety risk to our players, support staff and the community," Hockley said.
"This decision has not been made lightly and we are extremely disappointed, especially given the importance of continuing international cricket at this time, our valued relationship with CSA, and our aspirations to compete in the inaugural ICC world test championship."
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Tim Paine's Australia team just finished a 2-1 home series loss to India following a first defeat at the Gabba since 1988. South Africa is 1-0 down in Pakistan with the second and final test starting on Thursday.
Hockley said the South African and Australian cricket boards weren't able to finalize a bio-security plan for the series that was scheduled for March.
It's a setback for coach Justin Langer and test captain Paine, who were appointed in the wake of the ball-tampering scandal in South Africa in 2018 that resulted in 12-month bans for then captain Steve Smith and vice-captain David Warner.
"As difficult and disappointing a decision as this is, especially for Justin, Tim and the team, we have a duty of care to our people and their health and safety can't be compromised," Hockley said. "We look forward to playing the series at a date to be confirmed."
Australia selected two squads because of a schedule clash that involved a tour to New Zealand for five Twenty20s and the test series in South Africa.
It's unlikely any of the test players will be redeployed for the T20 series, with Cricket Australia saying when the separate squads were announced that there wouldn't be changes in personnel even if the South Africa series was scrapped.
South Africa also had to deal with a cancellation in early December when England withdrew from the ODI portion of its tour after a virus outbreak at the supposedly bio-secure Cape Town hotel where both teams were staying. Both squads had members infected, along with two hotel workers.
South Africa later hosted and won a two-test series against Sri Lanka which ended on Jan. 5 in Johannesburg.
- With AP
