How the bloody hell do you bat on a pitch like this? You don't. You survive. Or try to survive. So far, not so good for everyone who has dared take guard on Eden Gardens' nightmare surface.

We've seen nine batters reach 20. Only two have made it to 30. None have touched 40. We've seen 26 wickets fall in the 152.2 overs bowled in two days, or one every 5.5 overs. We will likely not see much play on Sunday before the match hurtles to its train crash of a conclusion.

South Africa will resume effectively 63/7 in their second innings. That would be a hopeless position on a proper pitch. On this surface, which will likely dwindle to deeper degrees of impropriety on Sunday, they have a sliver of hope. Not least because a target of more than 100 has been successfully chased just once on this ground.

That was in November 2004, when India made 120/2 in the fourth innings. Their opponents? South Africa. Jacques Kallis scored 121 in the first innings. That the visitors' current line-up doesn't include anyone of his quality is as true as the strong likelihood that he wouldn't have made anywhere near as many runs on this surface.

It's typical of the interesting times in which he lives that much will depend on Temba Bavuma. South Africa's captain survived for 78 balls - not many of which met the middle of his bat - for his 29 not out.

Ryan Rickelton would have been out lbw in the third over of South Africa's second innings had the toe of his bat not scraped Jasprit Bumrah's 141-kilometres-an-hour delivery, which pitched on a length, that had somehow not risen even 14.1 centimetres. Bumrah's next ball landed in about the same place - and steepled to hit Rickelton in the ribs and scurry away for four leg byes.

Aiden Markram was caught behind off an unplayable delivery from Bumrah on Friday. It reared like a rocket and had no business taking the shoulder of his bat, but it did. On Saturday Markram top-edged an ill-played sweep off Ravindra Jadeja and was caught at short leg. Markram sauntered off effing and blinding - a brute of a ball one day, a silly shot the next.

Unfairly, it fell to Simon Harmer to answer the question in paragraph one above. Harmer earned his press conference victimhood with a haul of 4/30 in 15.2 overs. He bowled with guile, turn and bounce. And with composure - a mad pitch is one thing, making use of it another.

His eighth delivery of the innings, a looping, turning effort, confounded Washington Sundar and had him caught at slip before lunch. Three balls later Harmer had an unusual hand in Shubman Gill's removal from the crease. India's captain slog swept him through backward square for four so violently that he injured his neck in the process and had to retire hurt.

After lunch Harmer stooped and clung to a low return catch offered by Dhruv Jurel. Then his scudding arm ball trapped Jadeja in front. Then he ended the innings - Gill did not return - by finding the bounce that made Axar Patel's cut fly into Marco Jansen's hands at backward point.

Thanks not a little to Harmer, and Marco Jansen, who took 3/35, South Africa - bowled out for a piddling 159 in their first innings - managed to limit India's lead to 30.

Nevermind all that. Simon Harmer, how the bloody hell do you bat on a pitch like this? "You've got to have very clear gameplans," Harmer said. "You've got to find ways to score. You need to try to get bowlers off their lengths, not just allow them to bowl.

"It's a difficult pitch to bat on, but if you put the ...it sounds so cliched and simple, but if you put the bad balls away when a bowler misses [their mark], it puts the pressure back onto them. It's about finding ways to do that because the ball is turning inconsistently.

"It's having that belief and positivity of trying to be positive on a pitch that probably doesn't allow you to."

Good thing Harmer has that worked out in his mind. He's due in when the first wicket falls on Sunday. Best he gets off the bus from the hotel already padded up.

As to how to bowl on this pitch ...

"You want to be testing batters on the front foot. If you allow them time to go back it allows them to adjust and play the turn off the pitch. Trying to test batters on the front foot, testing their front foot defence, allows the ball to spin past the bat and brings in both edges. And then you're trying to get one not to turn to try and bring in lbw. You need to be fuller rather than shorter on that pitch."

Now what?

"If we can get to [a lead of] 150, that would be incredible. But it's difficult to score and India have bowled well. So we've got our work cut out tomorrow. But Temba showed [us how] with his application. The tempo of his innings was very good. He's given us a blueprint for how we need to go about our business."

The South Africans weren't helped by Markram's stroke, a crazy cross-batted swipe by Kyle Verreynne to Patel that saw him bowled even as a close forced by bad light loomed, and more aggression than was needed by Jansen, and his consequent downfall.

But this wasn't the time nor the place - and especially the pitch - to complain about poor batting.

"It's very easy to pass judgement from the outside," Harmer said. "When you walk into that cauldron, the pressure, the ball turning, then not turning. The Indian boys know how to bowl in these conditions.

"They've done it for years and years.

"You've got to look to score. And sometimes the scoring option is a sweep and sometimes you get it wrong and you get out. It's the way the game goes. It's unfortunate that things didn't go more our way today."

The only other time Harmer played Tests in India was in November 2015. He was part of the 108-run defeat in the first match in Mohali and the 124-run whack the South Africans took in the next game, in Nagpur. Both pitches were substandard, with the latter rated poor by the ICC.

"The pitches in 2015 were probably worse," Harmer said. "In Mohali the pitch basically disintegrated on day one. Nagpur was the same. I can remember craters in the pitch."

Four days were washed out in Bangalore and, with the series safe, India won by 337 runs on a Delhi pitch that was starkly less treacherous than those in Mohali and Nagpur.

Harmer, who played his fourth and fifth Tests, took 11 wickets at 25.40. That seems a reasonable performance in a difficult series. But he was in the shadow of a giant.

"I was quite new to Test cricket, and Ravi Ashwin was bowling like a jet," Harmer said. "It was the expectation that I needed to do the same and dealing with that, and putting myself under even more pressure."

Ashwin took 31 wickets at 11.12 in the rubber. Harmer didn't play another Test until March 2022, against Bangladesh at Kingsmead. The Kolkata match is the eighth of his second spell. Where did he go for almost seven years?

"I wasn't good enough at the time. I didn't force the selectors to select me. And I signed a Kolpak deal [with Essex], which meant that I couldn't play for South Africa."

Dane Piedt cracked the nod ahead of Harmer initially, and the emergence of Keshav Maharaj at the head of a queue of spinners that includes Senuran Muthusamy and Prenelan Subrayen might have ended Harmer's hunger for Test cricket. It didn't.

"I've always had the desire to compete on the highest stage. And I've always wanted to come back to India after the experience of 2015. I'm my harshest critic. In 2015, when I got dropped from the national side, that was when I realised that I wasn't good enough.

"I came back to India in 2016 to work with Umesh Patwal [who runs an academy in Mumbai]. I discovered a lot about spin bowling that I didn't know. That was the point in my career that gave me the ammunition to get better and develop and become a decent spinner.

"I'm a lot more confident in my ability. I don't have as many doubts as I did [in 2015]. I was fighting for a place in the team then, whereas now I feel I have the skillset to compete. Whether or not it goes my way is sometimes the luck of the draw, but as long as I can look back and say that I put a good amount of balls in the right area, then I can be happy with that.

"And with having the subtle variations of balls that don't turn. Sometimes you get onto turning pitches and it's turning and you're just trying to turn it more and more and more, and sometimes the skill lies in bowling a ball that doesn't turn on a pitch that is turning."

The Eden Gardens surface has shaped the match more than any player so far. It would take some doing, but Simon Harmer may yet steal its spotlight.