India is playing England in a five-match ODI series starting on Friday in Rajkot and the only way the hosts, currently ranked third, can regain their number one ranking is by winning all the five matches of the series. A 5-0 win will see India jump two places to claim the top spot.
England too will be aiming to carry its Test form into the ODI format and win its first series in India in 28 years, and cement its status as the number-one ranked side.
South Africa too can move to the top of table as they are playing New Zealand in a three-match series starting on 19 January in Paarl.
However, the Proteas can only go top if it wins all three matches against New Zealand and India wins its series, but fails to complete a clean sweep.
England currently leads second-ranked South Africa by a fraction of a point, but will take an outright lead on the championship table if it wins the series, irrespective of the results of the South Africa-New Zealand and Australia-Sri Lanka series (starting on Friday in Melbourne).
In ICC ODI Player Rankings, no fewer than seven batsmen featuring in the top 10 are likely to figure in the India-England, Australia-Sri Lanka and South Africa-New Zealand series.
Hashim Amla currently leads the pack with his team-mate AB de Villiers second. India's Virat Kohli in third spot leads his captain Mahendra Singh Dhoni by 35 ratings points, and he will not only be aiming to strengthen his position with a strong performance against England, but also put pressure on South Africa's ODI captain.
It is expected that the series will result in fewer changes at the top of the Reliance ICC Player Rankings for ODI bowlers, where number-one ranked Saeed Ajmal of Pakistan is currently enjoying a comfortable lead over second-placed teammate Mohammad Hafeez.
As many as five of the top 10 are expected to be in action during the three series, including Lonwabo Tsotsobe, Morne Morkel, Steven Finn, Ravichandran Ashwin and Dale Steyn.
The tussle for the top spot on the Reliance ICC ODI Championship Table is also a build-up for the ICC Champions Trophy, scheduled to be held from June 6 to 23 in England and Wales.
Group A includes defending champion Australia, 2000 winner New Zealand and 2002 champion Sri Lanka, along with host England, which reached the final when it last staged the event in 2004.
Australia and Sri Lanka face-off on 17 June at The Oval in a day-night match during what will be the final edition of the ICC Champions Trophy.
While Australia and Sri Lanka may not be in the race for the number-one position on the Championship Table, the five-match series will provide both sides an opportunity to size each other up.
Sides in Group B of the ICC Champions Trophy are 1998 winner South Africa, 2004 champion West Indies, 2002 winner India, and Pakistan.
The tournament opener will feature the two former winners when South Africa takes on 2002 champion India in Cardiff on 6 June. The following day, the West Indies will face Pakistan at The Oval.
The semi-finals of the ICC Champions Trophy will be staged at The Oval (19 June) and in Cardiff (20 June), while Edgbaston will be the venue of the final, to be played on 23 June.
With 14 ratings points separating number-one ranked England from sixth-ranked Sri Lanka, the battle for the Reliance ICC ODI Shield and a cash award of USD 175,000 is truly warming up.
While India-England and Australia-Sri Lanka will square-off against each other from Friday, and South Africa will take on New Zealand from 19 January, there is a number of additional series to be played before the 1 April cut-off date.
Australia will take on the West Indies between 1 and 10 February, England will travel to New Zealand for a three-match series from 17 February, and South Africa will host Pakistan in a five-match series from 10 March. Every match counts as the six leading sides battle to finish inside the top two.
The side that tops the Championship table on the 1 April cut-off date collects a cheque of US$175,000 along with a Shield, while the team that finishes second receives a cheque of US$75,000.