Can India maintain their intensity?
Playing his first Test in a year, Zaheer Khan bowled 60.3 high-intensity overs at the Wanderers, eight of them in one spell after tea on the final day. That's nine more than he has ever bowled in a Test match. He is 35 now.
Ishant Sharma - say what you will about his bowling and his consistency - bowled 54 overs for his five wickets, his strikes in both innings bringing India back from the brink. He will always run in for his captain, he will always throw himself at the ball, he will always try to get behind the line when batting. That - and not just the lack of options - is why he has played 50 Tests for India.
Mohammed Shami bowled 46 overs. He was the most threatening of the lot, but possibly didn't get as many overs because he was in only his third Test and also needed to stay fresh to stay at his most threatening.
In three days' time, it is quite possible that the same three will be asked to bowl again. If Kingsmead rolls out a greentop, MS Dhoni will have to think twice before putting South Africa in because of this workload. The cost of competing against the best side in the world, and the most resilient one too, in a gruelling Test, has been high. This Test was longer than India's last Test series. India have put in less effort to win series. They must be wondering what else they need to do to beat South Africa in South Africa. Somehow, though, if India can maintain this kind of fitness, intensity and skill while bowling, this cost, or rather their willingness to pay it, might be India's biggest gain from this series.
They needed a spark, which came through Virat Kohli's hundred on the first day, but after a collapse and a strong South African start later, India were staring at a familiar scenario playing itself out: that of not keeping at it long enough in an away Test. The bowlers, though, kept at it. The results came. A lead was secured. In the second dig, the batsmen all but batted South Africa out. They gave the bowlers 135 overs to bowl South Africa out. India hadn't even required the second new ball in the first.
You look at the scorecard and see seven wickets falling in all those overs - two of them run-outs, one an ordinary lbw decision - and you might say it all did return to type. That, though, would be as unjust to India's efforts, and indeed to their skill with the ball, as it would be to South Africa's great will to fight. There wasn't much that India did wrong in that attempt to win. It might be said that had more time been available South Africa would have won this one, but it was India who consciously killed that time off by batting long in their second innings.
If we were to pick nits, that period of batting on the fourth morning when India just batted without direction in order to kill off three hours was when India didn't think straight. Not giving South Africa enough time was all good, but had they gone a little quicker they wouldn't have had to worry about saving the Test in the end. This isn't criticism in hindsight: India drew the match anyway.
The bowling itself will be worse on many days and will still bowl teams out. Faf du Plessis and AB de Villiers played gems, but questions were asked of them throughout. India have been guilty, in the past, of spreading the fields far and wide in the face of a slight counterattack, but it didn't happen here. Dhoni tried to make sure there was a fielder in place should his bowlers produce the edge. The edges all evaded fielders, though. When India usually concede 312 for 5 in a day's play, their bowlers and fielders are all over the place. Here they were at the batsmen. Du Plessis will tell you this was not easy.
R Ashwin's role will come into question, but he didn't bowl too badly either. Perhaps he should have stuck to his role of holding one end up - his economy rate of 2.3 over 36 overs suggests he did - but when wickets are not falling, you sometimes get desperate. He didn't come too close to getting a wicket, though, and that will concern him. This was the first time he had runs to play with in an away Test. He will be disappointed in that regard, but he wasn't way off the mark with his bowling.
It was only in that final session that signs of tired Indian fingers and shoulders began to appear. Zaheer began bowling short and wide, going for three boundaries in the first three overs of that spell, but bowled an eight-over spell to try to set things right. During this spell he could have had de Villiers lbw, but he himself didn't go up properly. Herein might lie Dhoni's only questionable move of the day. Bowling Zaheer for so long kept Shami away. He was on the field, he was fit, but Dhoni went 34 overs and a tea break without bowling him. Possibly Dhoni didn't trust this inexperienced bowler. Possibly he was waiting for one wicket to fall so he could unleash a fresh bowler who - if he didn't get a couple of wickets - would at least shut the scoring down.
The fielding, though, remained top-notch. Even Zaheer kept diving to save singles. When the run-out opportunity came, India took it. Kohli spoke of that desperation after the draw. "Every single person in this team is hungry to go out there and win a game for their country and their team," he said. "That is the biggest factor that has changed the way we played in the last one year. It is because everyone is hungry and desperate to go out there and perform and win from any situation. That's what this team believes in, that we can win from any situation."
Towards the end, Dhoni had to ask South Africa if they wanted to go for it. Those three overs was the only time India really spread the field - they even bowled one more over than they were required to. Dhoni asked Vernon Philander and Dale Steyn if they wanted to be heroes and risk losing it all. They didn't. Neither side can be blamed considering what was at stake.
There will be obvious disappointment that they couldn't win from this situation, but India made South Africa reach into their deepest reserves in their home conditions after a season during which they hadn't let a single Test reach the fifth day. Both teams will have to pick themselves up pretty fast, India more so than South Africa because there aren't many instances of their bowlers doing well in back-to-back Tests outside Asia.
Sidharth Monga is an assistant editor at ESPNcricinfo