DH Deciphers | How did India lose top Test spot when no team has played a match since March?

India are no longer the No. 1 Test cricket team in the world, a position they had held since October 2016. They lost the top slot on May 1 when the International Cricket Council (ICC) revised the Test rankings. India are now ranked third, behind Australia and New Zealand. The last time India played a Test series was against New Zealand in late February and early March, and they lost it 0-2. But there's been no cricket anywhere in the world for two months now. So how did India lose two positions? Well, blame it on complicated rules and a quirk of fate. Here's how:

How are team rankings calculated?

The ICC team rankings system is a rating method developed by British cricket statistician David Kendix. It ranks men's teams playing across Test, One-Day International and Twenty20 International formats, and women's teams playing ODI and T20I cricket.

The points are awarded based on the strength of the opposition. A win against a stronger opposition fetches more rating points than a win against a weaker team. Rating points at the start of the series are used as a measure to determine the strength of an opposition.

A series win fetches an extra point, which is equivalent to an extra Test win. So if a team wins a series 2-1, it will count as a 3-1 win. No extra weightage is given to an away Test.
The total number of points earned divided by the total number of matches or series played during the rankings period gives a team its overall rating.

When are the rankings updated?

The ICC normally updates the Test rankings after each Test match (usually within 12 hours) and the ODI ratings at the end of each series. It generally doesn't publish Test rankings if another Test match is in progress. However, if there are many overlapping Test matches, then a more flexible process is adopted so that the rankings don't get too out of date.

But there's been no cricket since early March. So how did India lose the top rank?

As stated above, the ICC rankings method is very complicated, including the way it considers the time period to rank the teams. A minimum of 36 months to a maximum of 48 months are considered. Every May, results from months 37 to 48 and the points accrued during that period are culled. For example, for the latest rankings, the time period considered was from May 2017 to date. This meant that results between May 2016 and April 2017 were dropped. This is where India suffered the most because they had won a whopping 12 Tests and lost just one between May 2016 and April 2017.

But this still doesn't explain why they lost two positions.

This has to do with how older results are weighted compared to the recent ones. The first two years get 50% weightage and the last 12-24 months 100%.
For example, on May 1, 2020, all matches from May 2017 to April 2019 get 50% weightage while matches played after May 2019 get 100% weightage. Between May 2017 and April 2019, India lost away series against England and South Africa while beating Australia in Australia. After May 2019, India did beat lower-ranked West Indies (2-0), South Africa (3-0) and Bangladesh (2-0) but lost to New Zealand (0-2) this year. In the same period, Australia drew with England 2-2 to retain the Ashes while blanking Pakistan (2-0) and New Zealand (3-0), thus gaining more (100%) weightage. What also worked in their favour is that the Test series they lost to India in 2016-17 no longer counted.
Australia now has a rating of 116, New Zealand (115) and India (114).