Since December 2013, when he replaced Sachin Tendulkar as India's Test No. 4, Virat Kohli has been the most prolific No. 4 in the world. Steven Smith has averaged more than his 62.04, but the Australian captain hasn't played as many innings at that position. Kohli has achieved these incredible numbers despite having two utterly forgettable series in between. He did, however, have the advantage of, on an average, walking out later than any other No. 4 in the world.

Over this period, India have lost their second wicket at roughly the end of the 27th over, six balls later than Pakistan and 10 balls later than Australia. In England in 2014, India were two down at around the 21st over, and somewhere near the 29th in Australia later that year.

In England, Kohli averaged 13. In Australia, 87.

Kohli is not a batsman without weaknesses - the moving quick ball troubles him often - but if the bowlers are even slightly off or if there isn't swing or seam, he takes full toll. The bowler knows Kohli can be taken out but he also knows the margin of error is almost non-existent. It will be unfair to attribute all the difference between Kohli's England and Australia tours to it, but for a batsman such as him, walking out to face an older ball and less-fresh bowlers makes a sizeable impact.

Every side needs players like Kohli, frontrunners who demoralise opposition attacks, but, as he himself would have realised, India need M Vijay and Cheteshwar Pujara to shield him from the new ball. Kohli the captain has a history of dropping them for more exciting batsmen, and in the one Test they both missed, Kohli - batting at No. 3 to accommodate Rohit Sharma - was exposed to the new ball and lasted 25 balls across two innings.

Virat Kohli smashed a double-hundred at his home ground AFP

The man who follows Kohli in the batting order also likes to dominate bowlers. Ajinkya Rahane, in fact, matched him shot for shot in the Boxing Day Test of 2014 as both batsmen scored superlative hundreds. The thing is, Rahane is also one of the worst starters in Test cricket. He has been dismissed for less than 20 in 47% of his innings over the last three years. Only Kusal Mendis fares worse among middle-order batsmen, and even if batsmen from the top three were added to the mix, only five of them paint Rahane in better light. To complicate matters, he is coming off his first series without a meaningful contribution in even one innings.

Having said that, and quite like Kohli, Rahane is an extremely important player for India. Apart from having the ability to run away with the game quickly, he is that rare batsman who plays better away from home, who has to work harder against spin than pace. India's only win in their 13-Test jaunt in England and Australia in 2014 and 2015 came on the back of a Rahane century on a green seamer.

For various reasons, these two domineering batsmen need a bit of tender care. India can't have them exposed to fresh bowlers and the moving ball too often. That is exactly why they need Vijay and Pujara at their best. Since December 2013, visiting No. 4 batsmen have been walking out, on an average, in the 20th over in South Africa. It is a tough place to face the new ball. You will see the seamer's version of intended offbreaks that don't turn. The top order will have to negotiate high-speed outswingers that pitch and suddenly either hold their line or nip back in. So when the ball is new, you almost have to play to have your outside edge beaten. Cover for the seam back in, never mind the one that beats your outside edge.

Ajinkya Rahane lifts one over midwicket AFP

You have to leave a lot of balls, and as it turns out, since December 2013, only Alastair Cook has done so more often against fast bowling, because he faces more of it, than Vijay (1158 balls). Pujara with 1065 leaves is not far behind. In terms of percentage of balls left alone, only Tom Latham is ahead of Vijay. Over the last three years, on an average, only four players have dealt with more fast bowling per innings than Vijay (59 deliveries).

You look at numbers outside Asia, and Vijay comfortably faces more fast bowling than any other Indian - 80 balls per innings to KL Rahul's 64 - and he faces them at their freshest. However, much like winter clothing, this is a game he leaves in the loft when playing at home or in similar conditions, which he has been doing a lot of over the last two years. He leaves alone 38% of quick deliveries outside Asia, and only 24% in Asia.

It is surreal that India toyed with the idea of not playing Vijay until as recently as the Sri Lanka series; he has appropriately come back with successive centuries, but he will have to quickly go back to being watchful again. He will be physically challenged, forced to duck and weave, and mentally taxed, with a lot of effort spent for few runs. He is also 33 now and has had a wrist surgery to go with back issues this year. It will be tough for him to replicate the restraint and technical expertise he displayed over long periods on India's last leg of tours outside Asia.

M Vijay and Cheteshwar Pujara rehydrate during the drinks break AFP

A similar batsman, Pujara will have to fight what he doesn't always like: extra bounce and metronomic bowling. His last hundred outside Asia came in South Africa, but it has been four years now. He has always maintained that he didn't have technical issues. He got quite a few starts; 41% of his innings outside Asia since Johannesburg 2013-14 have been under 20, which, for the sake of comparison, is a better rate than Rahane overall. Now he goes to South Africa in the form of his life.

Between Pujara and Vijay, their first job is to shield Kohli and Rahane, strike-rates be damned. The other opener will take care of scoring quickly. India seem to have locked in on Shikhar Dhawan for the first Test, not least because he is the only specialist left-hand batsman in the squad. Dhawan has one hundred outside Asia and an average of 30, and seems to struggle against the moving ball, but it seems India are willing to gamble, at least at the start of the series. And even if Rahul gets his chance, you suspect he will be briefed to bat with urgency to balance the approach of the other two top-order batsmen.

Over the last two tours to South Africa, India have had only two real shockers with the bat: the first innings in Centurion in 2010-11 and the second innings in Durban in 2013-14. They all know - most of them from experience - that there are runs to be had on quick-scoring grounds. They will go into the New Year's Test with form, confidence and clarity of roles. They will back themselves to be all right if they start well. And if the pitches have extra spice, the batsmen will have to adjust on the fly and a find a way to not collapse in a heap.