With 17 Tests to go in the current World Test Championship (WTC) cycle, several teams are still in contention, and no team is assured of a place in the top two. Here is how the teams currently stack up.
India
Percent: 61.11, matches remaining: Aus (4 away)
India's emphatic win in Perth takes them back to the top of the WTC points table, and keeps their chances of making it to the final at Lord's next year very much alive. To be certain of finishing among the top two without depending on other results, India still need to beat Australia 4-0: four wins and a draw will lift India to 65.79, which will be marginally more than New Zealand's maximum (64.29) if they blank England 3-0 at home. India will then be at worst second on the points table, after South Africa, who can finish on a maximum of 69.44 with 2-0 home wins against Sri Lanka and Pakistan.
However, these scenarios are based on other teams maximizing their points. If that doesn't happen, India can still make it with far fewer points. If, for example, these results happen from the key upcoming series:
India lose to Australia 2-3
New Zealand draw with England 1-1
South Africa draw 1-1 at home in both their remaining series, versus Sri Lanka and Pakistan
Australia draw 0-0 in Sri Lanka
Then Australia will finish on top at 58.77, but India's 53.51 will still be enough for second place, ahead of South Africa (52.78), New Zealand (52.38) and Sri Lanka (51.28). Thus, where India finish up will also depend on how the other results pan out.
Australia
Percent: 57.69, matches remaining: Ind (4 home Tests), SL (2 away)
The defeat in Perth means Australia have plenty to do to finish among the top two without depending on other results. Given that South Africa and New Zealand can both finish on more than 64%, Australia need five wins in their last six to finish ahead of New Zealand's maximum of 64.29; in this case only South Africa, with a maximum of 69.44, can finish ahead of them.
If India win the ongoing series 3-2, Australia can still finish ahead of them, but only if they sweep the series against Sri Lanka 2-0. In this case, Australia will finish on 60.53, marginally ahead of India's 58.77, but will need help from at least one of South Africa or New Zealand to finish in the top two.
South Africa
Percent: 54.17, matches remaining: SL (2 home Tests), Pak (2 home),
While much of the focus of the cricket world is on Australia and India, there's another huge series about to start in South Africa, who take on Sri Lanka and then Pakistan at home. If South Africa win each of their four remaining Tests, they will finish with 69.44%, which will surely be enough for qualification, as only Australia can go past that number. Three wins and a draw will leave South Africa with 63.89, while three wins and a defeat will lower the percentage marginally to 61.11. If South Africa finish on 61.11, it's possible for three teams to go past them - New Zealand, plus two out of Australia, India and Sri Lanka. That means South Africa can't afford to drop too many points if they want to make it to Lord's next year.
Sri Lanka
Percent: 55.56, matches remaining: SA (2 away Tests), Aus (2 home)
Sri Lanka are in a similar position to South Africa, which is what makes the series doubly interesting - they are on 55.56% with four Tests to go. However, unlike South Africa, only two of those matches are at home, against Australia. If they win each of those matches and take home 48 more points, they will finish on 69.23% and assure themselves of a place in the final regardless of other results. If they lose one and win three they will end up at 61.54, which will still leave them with a chance of qualifying. However, as with South Africa above, that will leave them depending on other results, as New Zealand and one of India or Australia can go past them.
New Zealand
Percent: 54.55, matches remaining: Eng (3 home)
At the start of the series in India, it seemed highly improbable that New Zealand would still be in contention for a place in the final at the end of the series in India, but three incredible wins have given them the chance to dream. If they win each of their three remaining Tests they will finish on 64.29. It won't ensure qualification, but it will certainly keep them in the mix. If they lose one of those Tests, though, their percentage will drop to 57.14, which will still keep them in the hunt depending on other results.
Pakistan
Percent: 33.33, series remaining: SA (2 away), WI (2 home)
Pakistan's home form has shown some revival, but it's most likely too late in this cycle. If they win each of their four remaining Tests, they will finish on 52.38. They will need several results going their way to be in contention. If, for instance, Sri Lanka lose 0-1 in South Africa and draw 1-1 against Australia, India lose 1-2 in Australia, and New Zealand lose 1-2 versus England, then Pakistan's 52.38 will be enough for second place behind Australia.
England
Percent: 40.79, matches remaining: NZ (3 away)
The two defeats in Pakistan means that England can finish with a maximum of 48.86 percent even if they beat New Zealand 3-0 in their last series of the current cycle. It's almost certain that it won't be enough for qualification, though there's a mathematical chance of finishing second on 48.86 if several other results go their way: if India get no more than 13 points from their remaining games, with the upper limits being 18 and 16 respectively for South Africa and Sri Lanka, then England can still finish second to Australia.
Bangladesh
Percent: 27.50, matches remaining: WI (2 away)
The four defeats in their last four Tests against India and South Africa have hurt Bangladesh badly - from 45.83% they have dropped to 27.50. Even if they win each of their two remaining Tests, they will only improve to 39.58, which won't be enough for a place in the top two.
West Indies
Percent: 18.52, series remaining: Ban (2 home Tests), Pak (2 away)
West Indies have already played four series and have only scored 20 points out of 108. Even if they win their last four Tests, they can only finish on 43.59%.