Ironically, India have risen to the top in a format some would accuse them of neglecting - and their low frequency of Tests could cause them to lose their crown sooner rather than later. They are only the third team, after Australia and South Africa, to reach the summit of the ICC's Test rankings since they were introduced in 2001 but their time there could be brief because of a schedule that contains only two Tests in the next 11 months.

Which means the duration of their reign will be determined by how their closest rivals, South Africa and Australia, fare in the next few months. "It is a bit of a concern, as we play only two Test matches in the next six months, so it will be tough for us to maintain the position," MS Dhoni said after India's victory in Mumbai. "I can't do anything about the schedule. It is good to play Test cricket, at the same time we are here to play whatever cricket we are asked to play."

Before their 2-0 victory, India were ranked third with 119 points after Sri Lanka and chart-toppers South Africa (122). The two consecutive innings victories in Kanpur and Mumbai earned India five points, taking them two clear of South Africa, while Sri Lanka slipped below Australia to fourth place.

During the period in which India have only two Tests - against Bangladesh - to maintain a hold on their No. 1 position, South Africa play at least four and Australia eight. A 2-0 win against Bangladesh isn't likely to give India too many ratings points either, so they could be overtaken depending on how South Africa do against England, and how Australia go against West Indies and Pakistan at home, and in the away series in New Zealand and against Pakistan in England.

What is certain is that India will end 2009 as the No. 1 Test side because even a 3-0 victory for Australia in the ongoing series against eighth-ranked West Indies will give them only one point, taking their tally to 117, and no improvement in position.

India's immediate threat is South Africa, but they will have to beat England by a 2-0 margin or better to reclaim the No. 1 spot. A 2-0 or 3-1 victory for South Africa will take them marginally ahead of India, 3-0 will given them 126 points, and 4-0 will extend their lead over India by three. However, if England win 1-0 or 2-1, South Africa's tally will reduce to 117, increasing India's lead by seven points.

If South Africa fail to recapture the top spot against England, India's reign will receive an extension because even if Australia blank Pakistan 3-0 at home, following a 3-0 win against West Indies, their ratings points will increase only by three to 119. They will then need to win in New Zealand and beat Pakistan in England - an away series for Australia - to move up the ladder.

ICC Test rankings

Team	Matches	Points	Rating
India	32	3957	124
South Africa	30	3672	122
Australia	31	3600	116
Sri Lanka	31	3574	115
England	39	4102	105
Pakistan	17	1424	84
New Zealand	25	2001	80
West Indies	25	1910	76
Bangladesh	19	255	13

Click here to see the ODI and player rankings rankings.