Australia and India find themselves in the box seat to qualify for the World Test Championship final ahead of the Border-Gavaskar Trophy, but all of South Africa, Sri Lanka, the West Indies and England remain a mathematical chance at qualifying.
The final, to be held in the first week of June at The Oval in London, will be the second World Test Championship final, with India and New Zealand contesting the first edition in 2021.
Here is how each of the remaining nations in contention can qualify.
Australia
Australia have been as close to perfect as it's possible to be in this cycle of the championship. They have lost just a single Test, coming in the second of two against Sri Lanka during July of last year. With the only other blip on the record being four draws, and coming off resounding 2-0 wins against the West Indies (two-Test series) and South Africa (three-Test series), they hold a percentage of 75.56.
So far ahead are they that with just four Tests remaining, they can technically qualify with a 4-0 defeat against India. The only way they wouldn't qualify after a 4-0 drubbing would be if Sri Lanka beat New Zealand 2-0 in New Zealand, which is unlikely.
A 3-0 loss to India would mean Australia qualify regardless of other results - so just a single draw will be enough.
India
India are also able to handle their own destiny, but should Australia spring an upset on the sub-continent, then they are in far greater danger of missing out on the final than the Aussies.
A current percentage of 58.93 leaves them just five per cent ahead of Sri Lanka, 10 per cent ahead of South Africa and 12 per cent ahead of England, who are the other realistic chances of qualifying.
To assure their qualification, India need to win their four-Test series against Australia 4-0, 3-0 or 3-1. That would give them a percentage of either 64.35 or 62.50, which is ahead of the maximum Sri Lanka (61.11) or South Africa (55.56) can gain via a 2-0 win over New Zealand and the West Indies respectively.
Anything less for India, and they will be relying on other results to go their way. A 2-0, 1-0, 2-1 win or 2-2 draw would leave India relying on Sri Lanka to not beat New Zealand 2-0.
Sri Lanka
For Sri Lanka to qualify, they will need India to not beat Australia 4-0, 3-0 or 3-1. Any of those results lock the World Test Championship final in place, although a 4-0 win for India and 2-0 win for Sri Lanka over New Zealand would knock Australia out.
Sri Lanka will be out to win 2-0 and hope the rest takes care of itself.
South Africa
For South Africa to make the final, they will need even more to go right. It goes without saying they need a 2-0 win over the West Indies. If they manage that, they will then need Australia to beat India, and for Sri Lanka to not win 2-0 in New Zealand. A 1-0 win for Sri Lanka over New Zealand combined with a 1-0 win for Sri Lanka would leave the teams equal on percentage, but of course, they'd then be relying on India doing no better than 1-1 against Australia.
England
England finished their World Test Championship campaign with a percentage of just 46.97. For them to qualify, they would need India to lose 4-0, Sri Lanka to lose 2-0, and the West Indies to beat South Africa 1-0. It's a very specific string of results that seems unlikely.
West Indies
The West Indies would need a 2-0 win over South Africa to elevate their percentage to 50.00. They would then need New Zealand to win either 1-0 or 2-0m and for India to lose either 2-0, 3-0 or 4-0 against Australia.
