South Africa on Monday strengthened their position as the number-one ranked side on the ICC Test Team Rankings table courtesy their 10-wicket victory over India in the second and final Test in Durban.
The 1-0 series win has helped South Africa gain two ratings points to finish on 133, while India have conceded two ratings points to end at 117.
This means the gap between the two top ranked sides has now increased from 12 ratings points to 16 ratings points.
Meanwhile, Australia have an opportunity to finish third on the rankings table.
Australia had entered the Ashes series in fifth position on 101 ratings points, but after taking a 4-0 lead against England, they are guaranteed fourth position on the table. And Michael Clarke's side will gain one more place if they remain unbeaten in the Sydney Test, which starts on January 3.
The only way England can defend their third position on the table is by winning the Sydney Test. In this scenario, England will end on 109 ratings points while Australia will finish on 108 ratings points.
Pakistan, which will slip to fifth irrespective of how the Ashes conclude, can keep the pressure on Australia and England if they win the series against Sri Lanka.
If Pakistan win 2-0, then they will move from 102 ratings points to 105 ratings points, while they will finish on 107 if they win all the three Tests.
On the other side of the coin, Sri Lanka have a chance to move ahead of Pakistan if they win the series 2-0 or better. If they win 2-0, they will jump from 88 ratings points to 95 ratings points while Pakistan will slip from 102 ratings points to 94 ratings points.
With the top four sides as of December 31, 2016 qualifying for the inaugural ICC World Test Championship scheduled for 2017, every Test counts towards the qualification.
The qualification pathway for the World Test Championship is through the ICC Test Team Rankings, with the qualifying period being from May 1, 2013 to December 31, 2016. The top four teams at the conclusion of the qualification period will qualify for the event in 2017.