England v South Africa, 2nd Investec Test, Trent Bridge, 1st day July 14, 2017

De Kock keeps it simple after answering du Plessis' call

South Africa needed some no-nonsense impetus to their batting and that is exactly what they got from promoting Quinton de Kock to No. 4 in the order

A batting position is a batting position, a pitch is a pitch and scoring runs is, well, scoring runs - at least if you're Quinton de Kock. Some call it simplicity, others have less complimentary ways of explaining how de Kock does or doesn't think about the game but no one can deny that his approach works.

Not even South Africa. Having stubbornly kept de Kock at No. 7, even with most of the top five struggling, they chose Trent Bridge to try something different. It was a brave choice, all things considered, but it was a choice returning captain Faf du Plessis had to make given the events leading up to it.

After dropping JP Duminy, du Plessis chose to bat under cloudy skies, at a venue where England have won six of their last seven matches - including a drubbing of Australia in 2015 - with a batsman short and a line-up that had been bundled out for 119 five days ago. The captain asked a lot of his men and two of the top three answered as carefully as they could (Dean Elgar, unusually, the exception) but du Plessis needed more reassurance than that. So he sent in the person whose answers don't involve too many words but plenty of action.

"I was asked," he said afterwards. "I've always like to bat higher but the team make-up has never really allowed me to. A couple of selection things came up. I just put my hand up.

"It didn't change much in my game plan, obviously knowing that I might need to be a bit tighter coming up against a newer ball. Mentally going into it I was the same. I just kept it simple."

De Kock is a doer, not a planner or an analyser. It would not have bothered him that Heino Kuhn and Hashim Amla were scoring at a little over two-and-a-half runs to the over, that the ball was swinging, that James Anderson had taken his 300th wicket at home and that Stuart Broad was the person chiefly responsible for Australia's collapse two years ago on a similar surface, in similar conditions. The only thing on his mind would have been to get on with it, so that's what he did.

Most importantly, de Kock looked like a man who was confident about what he was doing, the exact opposite of Duminy a week ago

He left just two of the first nine balls he faced and defended one. Three others he tried to flick through the leg side, he got forward to two and hooked one. He was not just looking to score from the beginning of his innings but looking to score quickly.

The 14th ball de faced scooted past backward point off an outside edge, a drive gone wrong, and the substitute fielder had a fairly long chase on a sluggish outfield. Amla was comfortable with two but de Kock pushed him for a third. The next over, de Kock did that again. Amla looked a little exasperated both times but also a little excited.

That de Kock brings out a more youthful side of Amla is evident in shorter formats, where Amla plays with so much freedom that he has recently been criticised for recklessness. But here, with de Kock at the other end, Amla was pleasantly more urgent. The over after de Kock struck back-to-back boundaries on either side of the field, Amla came down the track to launch Liam Dawson down the ground for six, and bring up fifty. It had taken Amla 93 balls to get to the milestone but only 33 after de Kock's arrival at the crease and, in that time, Amla scored 24 runs.

At times in the Amla-de Kock partnership the scoring rate was over five and there was a real sense South Africa were seizing some control. They took on Dawson and Ben Stokes, who was loose in his first two spells, they ran well between the wickets and they rode their luck. Amla was dropped on 56, de Kock inside-edged on 50. On another day, South Africa would have lost them both but this time they survived.

By tea, the de Kock experiment could be declared a success. He had overtaken Amla in run terms and looked at home in the middle, he had made du Plessis' decision look a decent once, with runs coming fairly easy and damage limited. More importantly, de Kock looked like a man who was confident about what he was doing, the exact opposite of how Duminy had looked a week ago.

Too confident, perhaps. When de Kock nicked the first ball after the break, one he could have left, he again added himself to list of South Africa batsmen who have got starts but not converted them. That could well be the difference between the two sides at the end of the series and it is an issue South Africa need to address but they don't need to labour the point with de Kock just yet.

Quinton de Kock strolled to a 59-ball fifty as he and Hashim Amla pushed England back © Getty Images

With the line-up South Africa have now, they need someone who is not as shackled by expectation or form as the rest to just bat. That someone is de Kock. In his own words a few weeks ago, his is mostly just a "see ball, hit ball" way of doing things. Though that may mean squandering a few opportunities to get really substantial scores, it will give South Africa someone who change the pace of the game in a short period of time.

The question will soon become whether de Kock can do that from the No. 4 position in the long term and this Test will be a good case study. He still has to keep wicket and then bat again. Although he is young and fit, a workload that high over a period of time may not be sustainable. South Africa could consider asking Kuhn, a first-class gloveman for a decade, to share some of the burden in this series or they may decide to be flexible about de Kock, especially because he has also been valuable at No. 7.

From a seemingly difficult position to score big runs low down in the order, de Kock has accumulated 825 in 18 innings there, averaging 58.92 and scoring all three of his hundreds. And South Africa have the lower-order to support him. For the second time on the tour, Vernon Philander contributed crucial runs and Chris Morris is no mug either. Ask the two of them about their approach to batting and they will give you much more strategic answers than de Kock, particularly Philander, who is hopeful a maiden Test hundred is not far away.

Philander accompanied de Kock to the Gunn and Moore factory earlier in the week and had two new bats made, specific to his requirements. De Kock had a look around and concluded, "A bat's a bat; wood's wood." And for him, it does the job.

Firdose Moonda is ESPNcricinfo's South Africa correspondent