De Kock the puzzle in South Africa's jigsaw

Down-time for Quinton de Kock Getty Images

With a 2-0 series lead and an eye on closing the gap between themselves and India to a fraction of a point at the top of the Test rankings, it would seem South Africa don't have any serious concerns ahead of the finale but there is one. After three scores under 20 in his four innings in the series, and a long-format lean patch stretching back several months, the form of Quinton de Kock has become a worry especially if the team strategy of six specialist batsmen is going to hold in the long term.

De Kock's last Test score of significance was his 68 in the first innings against England in Nottingham in July. He was batting at No.4 in that match, after JP Duminy was dropped and de Kock, one of the few in-form batsmen at the time, was given the freedom to choose his position. But he only batted in that position for two matches before Temba Bavuma took over and now the job has gone back to AB de Villiers.

The promotion up and demotion back down seems to have destabilised de Kock. In his last 12 innings, de Kock has not gone past 50, only once for lack of opportunity, when he scored an unbeaten 28 against Bangladesh in October when South Africa declared at 573 for 4. Since then, de Kock has scored 24, 43, 8, 0 and 12 and while the rest of us are looking at the numbers and the history, Faf du Plessis wants de Kock to do the opposite.

"The key for someone like him is not to overanalyse or overcomplicate things. It happens when a guy goes one or two or five Tests without scoring runs, you tend to want to overanalyse but with Quinny that's the last thing you want to do," du Plessis said. "His biggest asset is that he is a free player and when he is on, he completely takes the pressure back onto the opposition. I know he would like to score runs. From the team perspective, the language we speak to him is to just keep having the positive intent and when he gets the opportunity to score runs, that he cashes in. He will be very hungry to put in a play in this last Test."

De Kock's natural aggression and instinctive style of play have bought him the licence to be considered a wild child, who will perform in sporadic bursts if left to his own devices. That may work in a side with the luxury of a seventh batsman and it has worked well for de Kock. He has made more than half his 1641 Test runs at No. 7, including all three of his Test hundreds, and averages 55.53 at that position. In contrast, de Kock has scored only 349 runs in 14 innings at No. 6 at an average of 26.84 with two fifties, both made back in 2014, and needs to start taking greater responsibility, which du Plessis has stressed in a series where batting conditions are tough. "If you get in, with your partner, try to string together a nice partnership," he said.

Du Plessis only expects it to get tougher at the Wanderers, especially for a player like de Kock, who prefers flamboyance over fastidiousness. "This is the ground where it swings a little bit more than anything else. Your disciplines as a batsman become important," du Plessis said. "When you do get through the tough times, that's when you get value for your shots. The outfield is very quick and the wicket can get good to bat on but there are challenging times for a batter and you need to get through them."

Happily, de Kock knows the Wanderers better than most. It was the ground where he played his franchise cricket at the start of his career and he understands its nuances. Perhaps even more happily, de Kock's long-time mentor, former national batting coach Neil McKenzie, was invited to attend South Africa's pre-Test training session, though not specifically to address the de Kock issue.

"He was just assisting. He was part of the Proteas set up for a while and his role going forward will be to look at the next tier of batsmen coming through. So it's just to see how we are working," du Plessis said. "I do know Neil has quite a good relationship with Quinny but he was going to come to Jo'burg anyway, before Quinny didn't get runs the previous game."

McKenzie played an important part in fine-tuning de Kock's game, as much as it could be fine-tuned, when de Kock was dropped early in his career after a tour to Sri Lanka in mid-2013. At the time, McKenzie was still playing franchise cricket and took de Kock under his wing, though he joked that as much as he talked, he wasn't always sure de Kock was listening. When de Kock was recalled to the side in late 2013, he scored his maiden ODI hundred against Pakistan, reeled off three against India, and made his Test debut the same season.

A (re)start so convincing may have to stall at some point but South Africa will want to get de Kock going again soon, especially since the slump has been long. De Kock had a poor domestic T20 campaign in November-December, when he played eight matches and scored 118 runs at 14.75, with a top-score of 39. With limited-overs matches looming, South Africa will want him to find the touch that took him to a sensational 168* against Bangladesh in the first ODI in October last year.

After that innings, de Kock credited the work he had been doing with McKenzie and South Africa will only hope the same can happen now, so they can fit the last piece of their Test puzzle into place before the Australia series in march.