Save India's great middle-order batsman Ajinkya Rahane

Over the last two years, India have seen an outstanding run of success, winning nine consecutive series. India's recently-concluded Test series against South Africa was one of the most hyped series in recent times.

Virat Kohli has always talked about winning overseas, as much as he has spoken about playing every game on its merit. While the ODI series has already started, they need to ponder on quite a few issues that arose at the end of the Test series and try not to repeat the same mistakes in future overseas tours.

One of the biggest points of debate is the selection of Rohit Sharma based on home form ahead of Ajinkya Rahane who has a stunning overseas record.

It is not often that a team drop their vice-captain for the first Test of a series. Rahane entered the tour of South Africa as the vice-captain of the team and also their most impressive batsman in overseas conditions. He is one of very few Indian batsmen with a better away record than home, with centuries at Melbourne, Wellington, Kingston and Lord’s to his name.

Having scored half-centuries in both innings of his second overseas Test, at Durban in 2014, it was clear that he was an exceptional batting talent.

Rahane - the batsman for all conditions

Overseas performance of Indian top order batsmen

Among India's current batsmen, only Rahane averages above 50 in overseas Tests. The difference in averages of Rahane and the other Indian batsmen tells the story. While Rahane averages 53.44, Dhawan, with an average of 45.51, stands second. The difference in average between the two is 7.93, and nobody would have envisaged that one day he would be dropped for Rohit Sharma, who averages a measly 26.33, less than half of Rahane's.

Performance of Indian top-order batsmen outside Asia

Dhawan has an exaggerated overseas average of 45.51 as a result of his performances in Sri Lanka and Bangladesh. He has performed poorly in Australia, England, South Africa and West Indies and averages below 40.

Rahane, meanwhile, has an outstanding overseas record in almost all the countries, scoring at an average of above 50 except in England where he averages 33.22. His ability to play in all conditions is the hallmark of his Test career.

Kohli is the second best when it comes to consistency, with an average of well above 60 in three countries. Kohli had one poor series in England where he averaged 13.4 and one average outing in West Indies, scoring at 36.33.

All these numbers indicate Rahane is an indispensable asset if India plan to win overseas Tests.

After being dropped for the first two Tests in favour of Rohit, Rahane returned for the third game after Kohli received immense criticism from fans, commentators and former cricketers for his decision. Rohit failed to deliver in the first two Tests, with scores of 11, 10, 10 and 47 at an average of 19.5 and drew flak for his below-par performances.

Rahane contributed in the final game and India's magnificent win in the final Test of the series will help him get a longer run in the Test format.

It was a bittersweet moment for Kohli seeing Rahane and Bhuvneshwar battling it out together in Durban, two men he had dropped in an earlier Test.

Rahane proved his worth through his partnership with Bhuvneshwar in the 3rd innings of the Durban Test, and one can only wonder what could have been had he played in the first two games of the series.