It was an emotion-filled Saturday in Adelaide in December 2014. At the first Test since the death of Phillip Hughes, the crowd heaved with expectation as Australia declared overnight to set India 364 to win on the final day. The pitch remained good, and Virat Kohli batted as though he could not make a mistake. M Vijay was solid in company. As half hour after half hour passed, India managed to stay within sight of their target, and slowly the dream of the impossible began to become all too real.

And then India lost Vijay for 99. They were 122 away from the target with eight wickets in hand, but this wicket began a collapse. Kohli could only watch from the other end as two more batsmen fell quickly, and then Wriddhiman Saha tried to hit every ball for a boundary. India's last five wickets added 38 runs. They lost by 48.

Eleven months later, as winter began to set in, India, having been smashed around for 438 in a home ODI, gambled on a Test track that would turn from ball one. This was a pivotal Test. This was Kohli's first series at home as captain. South Africa had beaten them in the ODIs. A team lacking in confidence had made a desperate move. They lucked out in winning the toss and had Vijay and Cheteshwar Pujara giving them a good start, but soon found themselves at 102 for 5. Had South Africa continued with the momentum, this young team could have ended up shattered. Then Ravindra Jadeja and R Ashwin scored 38 and 20, looking assured, as the last five wickets added 99 runs. South Africa's last five added 77. They fell behind by 17 on the first innings when they needed a lead of about 30 to be competitive. That turned the whole series, and a whole team, around.

Five days of hard-fought Test cricket can be won or lost on one moment, one spell of five or six overs, 15 extra minutes of resistance, a misadventure five minutes too soon. During their successful run in the last two-and-a-half years, India have won big moments thanks to their last five wickets, be it against South Africa in Nagpur, against West Indies in Gros Islet, against New Zealand in Kanpur and Kolkata, against England in Rajkot and Mohali, or against Australia in Dharamsala.

It is no wonder that the No. 1 side's last five wickets have the best average in the world since that Mohali Test in 2015. By comparison, India's last five wickets had fared better than only West Indies, Zimbabwe and Bangladesh during their 13-Test away run from late 2013 to early 2015.

On an average, the last five wickets have added 166 runs to India's totals during their dominant run since Mohali, a whole 53 runs more than the overseas run that left them at No. 7 on the ICC rankings. India's only win in those 13 away Tests came in a match in which Jadeja and Bhuvneshwar Kumar contributed significantly with the bat.

Just as it follows, India conceded the most runs of all teams to the last five wickets during their away run, and the fewest during their dominant run.

A lot of the recent success of India's lower order has been down to Nos 6, 7 and 8. Ashwin, Saha and Jadeja have occupied those positions for a large portion of this run, allowing India to play an extra bowler without giving up on lower-order runs. There has been no bigger symbol of the oppositions' helplessness against India in Tests since late 2015.

The three combined to do the job of at least two proper allrounders. India will desperately need that to continue on this away run; they might even take it if the Nos 6, 7 and 8 combine to form one complete allrounder. The last visiting team to win a Test series in South Africa had Ben Stokes, Jonny Bairstow and Moeen Ali at 6, 7 and 8. The spotlight might be on India's top five and the three quicks, but the three players in between might just end up deciding Tests if they are closely contested. The test for them will be the conditions. Lower orders, even more so than specialist batsmen, struggle to adjust to difficult conditions, not least because scoring runs is not their first skill.

R Ashwin and Ravindra Jadeja walk back at stumps AFP

Only one of India's three multi-dimensional players at home remains assured of a spot. India have been blessed that they are getting so many years out of Saha the wicketkeeper even though his career has coincided with MS Dhoni's, but it is for Saha the batsman that this tour will be challenging. He has copped a nasty blow or three even on docile tracks because of his predominantly front-foot game. While his tenacity has helped him score runs, he will have to dig deeper on bouncier tracks in South Africa. India's support staff will spend hours trying to equip him to do that.

An equal amount of work will go into a similarly front-foot-oriented but more explosive batsman, Hardik Pandya, who until not long ago was seen as the big hope for India going to South Africa, the kind of player India are not used to be travelling with, an upgrade on Stuart Binny. India even rested him for the home Tests against Sri Lanka to preserve him for South Africa.

However, a lot has happened since that selection call. In the two chances he has got, Rohit Sharma has scored two centuries. A big collapse on a green pitch in Kolkata - where Rohit didn't play - has reinforced the value of an extra specialist batsman in testing conditions. The two-day Test in Port Elizabeth might have told India that they won't even need a fifth bowler if the conditions are such. The choice between Rohit and Pandya will depend on the conditions: the friendlier they are for bowling, the likelier Rohit is to play, an opportunity to finally establish himself as a Test batsman.

Only on a rare greentop, conditions in which Pandya the bowler might be more effective than one of the two highest-ranked spinners in the world, can both of them play. That it is even a thought says something about how much India's spinners have needed conditions to be in their favour.

Vernon Philander, one of the biggest threats to India in this series, is a similar example of a bowler who has had to overcome doubt over his efficacy in conditions not explicitly suited to his style of bowling. He is not express, and doesn't usually swing the ball, which makes his accuracy key on pitches that don't offer him too much seam movement.

Back in 2014-15, when they toured South Africa Australia questioned Philander's achievements in their pre-series mind games. David Warner wondered aloud about a Test Philander missed two years ago. "I would have liked to see him bowl at Adelaide in that second Test when he apparently hurt his back - and was bowling in the nets three days later," Warner said.

However, if India's spinners can replicate Philander's stats in unhelpful conditions - average of 32 and economy rate of 2.42 in Asia, 30.12 and 2.82 in Australia - they might still take it provided he also makes a contribution with the bat. Ashwin right now has an average of 56.58 and an economy rate of 3.25 in Europe, Africa and Oceania, and Jadeja 46.16 and 2.70.

Ashwin and Jadeja will approach this series differently. Both must be smarting at being left out of India's limited-overs sides. If the spinner who gets selected first does well, the other could be looking at a year without any international cricket, given that India are not scheduled to play any home Tests this year. Ashwin has spent the time away working to add legspin to his game, Jadeja will have worked to perfect what he already does. Ashwin is technically better equipped as a batsman away from subcontinental conditions, but Jadeja has shown at Lord's that he can be the jack in the box. With Ashwin out of the slips, Jadeja carries a bigger value in the field. The abundance of right-hand batsmen in the opposition line-up and the absence of a left-arm quick in either side who could create some rough outside the right-hander's off stump might count in Jadeja's favour, but Ashwin has more variety and more experience.

India might have been tempted to take a wristpinner to South Africa - five of the eight spinners with 40 wickets or more in South Africa are wristspinners - but picking between Ashwin and Jadeja might not have been easy. The worst either of these two can now do is feel he has little to do. There's always that spell with two maiden overs that helps the fast bowler, there's always a partnership that needs to be broken, there's always the extra half hour you can spend at the wicket to help the other batsmen.

These three slots are India's less-fancied contributors in these conditions, but they are the ones India will need everything from should they happen to run South Africa close.