Faf du Plessis didn't know it then but as this decade was beginning, his cricketing future had been decided. He would be a captain.

Not just any captain, a long-serving franchise captain, a la Justin Ontong or Morne van Wyk. Except that du Plessis would be at Titans. Pierre Joubert was reaching his twilight years and du Plessis had been earmarked as his successor.

The idea seemed perfect. Du Plessis was a solid performer; not outstanding but consistent. In the 2007-08 season, he was the eighth highest run scorer in the first-class competition, averaging 39.33, and the following summer he was 15th, with 536 runs at 41.33. He was seen as more of a limited-overs player then, and he played a big role in Titans' victory in the List A competition in the 2008-09 season. He was also something of an allrounder: He bowled decent legspin and was outstanding in the field. He spent winters at Lancashire, rubbing shoulders with players of a similar ilk. He was so competitive that the team had to stop playing pre-match football for fear he would try to turn it into a premier league.

But the real reason Titans wanted du Plessis to take over from Joubert is one that no one is willing to be quoted on these days: they did not think du Plessis would become an international regular. They knew he had talent, but with the likes of Rilee Rossouw and Dean Elgar scoring more than 1000 runs apiece in first-class seasons, du Plessis was quite far down the queue.

Titans didn't know it then but du Plessis would leapfrog everyone, becoming not just a must-have in South Africa's international line-up but also the captain.

In April 2013, he was made South Africa's full-time T20 captain after having stood in for four matches (and also in two ODIs). In October 2016, three and a half years later, du Plessis has led South Africa to a historic 5-0 ODI whitewash over Australia, and will take them down under in an attempt to win a third successive Test series there. Whatever the outcome, the debate has already begun: should du Plessis lead South Africa in all formats, permanently?

There are no clear yes-and-no camps yet, perhaps because du Plessis is standing in for a close friend and a man widely considered the best batsman in the world, AB de Villiers. Suggesting de Villiers is not up to leadership is akin to saying Roger Federer may never win another Grand Slam. Even if people believe it, no one wants to be the first to say it. Instead, all there is to go on is evidence, so let's go back a bit.

In 2011, when Graeme Smith stood down as captain in limited-overs formats, South Africa were headed for a major overhaul. That winter they signed Gary Kirsten on as national coach, and appointed de Villiers as captain in the shorter formats, with Hashim Amla as his deputy. Du Plessis was still new in the set-up, having only debuted earlier that year.

When de Villiers was not available to captain his first series in charge, against Australia later that year, Amla had to step in. He also took a T20 squad to play in unofficial series in Zimbabwe in 2012, but in early 2013, when de Villiers was banned for a slow over rate - a problem that has plagued his captaincy - Amla asked to not be made to take over. Instead, du Plessis did the job, and in the aftermath Amla stepped down as vice-captain.

Three months later du Plessis was made permanent T20 captain. "AB has expressed that sometimes he feels that he is not sure about T20 cricket, so we have decided to give Faf the leadership," Kirsten said at the time.

De Villiers, who had never led at any level before being thrust into the job at the highest one, always looked a frantic captain. He made decisions by committee, which often included du Plessis, Amla and a clutch of bowlers. By de Villiers' own admission, captaincy was a role he needed to learn about. By contrast, it was something that had always come to du Plessis naturally.

"At school Faf was always the leader," Joubert said. "He took longer to develop from the superstar schoolkid, but as a captain he was a natural and people would follow him. He had a wonderful cricket brain."

All through that, Smith continued captaining, de Villiers had moved to permanent wicketkeeper, and du Plessis stepped up to bat at No. 3 because he wanted a more senior role. "He does not hide himself from responsibility. When Jacques Kallis retired, Faf said he wanted to bat No. 3," Joubert said.

Du Plessis' acceptance of duty was evident from debut, when he stonewalled and exhausted the Australian attack to force a draw in Adelaide. He did it again, in Johannesburg against India at the end of 2013. Both times de Villiers was by his side. As a pair, they were perfect to take South Africa forward, but they may not have expected how soon they would need to.

"Du Plessis also addressed transformation openly. De Villiers in contrast has often sent mixed messages. Even in his biography he did not come clean about what happened in the World Cup semi-final when Vernon Philander was included ahead of Kyle Abbott"

In March 2014, Smith announced what seemed a premature retirement. He gave South African three months to decide on a successor before they toured Sri Lanka in July that year. The obvious candidates were the leaders in the two other formats, de Villiers and du Plessis, but shortly before the announcement, Amla made himself available as well.

Amla said he felt ready to contribute, and with increased focus on transformation, and the glaring absence of a leader of colour, he was the perfect fit. De Villiers admitted being disappointed but promised to support Amla. Du Plessis was never asked how he felt.

In the beginning things went well. South Africa won in Sri Lanka, Zimbabwe, and against West Indies in Amla's first season in charge, and were rained out in Bangladesh at the start of his second.

With minimal long-form cricket behind them, they went to India to begin the toughest challenge of Amla's career. Du Plessis was the man to say they were expecting "the worst" on the eve of the first Test, and that is what they got. Pitches designed for India's spinners; serious injuries to their two opening bowlers, Dale Steyn and Vernon Philander; a washout in de Villiers' 100th Test, in Bangalore. Those and general all-round misery saw South Africa lose 3-0 and Amla become increasingly uncomfortable with his job. He kept it for the first match at home to England, which South Africa lost, and then decided he'd had enough. Not even a double-hundred at Newlands in a drawn game could make him change his mind. After the New Year's Test this year, Amla stood down.

His time in charge coincided with a period of great stress for South African cricket. Apart from the results and the injuries, there were also threats from de Villiers of premature retirement, the loss of form of du Plessis and JP Duminy, and increasing talk of strict implementation of transformation targets. Few would have wanted to take over then.

But de Villiers had long wanted to captain South Africa and accepted the job for the remaining two Tests against England, although he continued to discuss managing his workload through them. When South Africa lost that series, de Villiers was appointed permanent Test captain, but he inherited a South African side deep in depression.

They bombed out of the World T20, there was overall unhappiness and uncertainty over the coming targets - with white players considering their options overseas and black players writing a letter to CSA to complain about being used as tokens - and there was an axe hanging over the coach's head, which dropped ever lower on a winter tour to the Caribbean, where South Africa failed to get to the final of a triangular series. Luckily, before everything imploded, there was a break and there was the CPL.

All three of South Africa's leaders were there. Amla played for Trinbago Knight Riders, de Villiers for Barbados Tridents, and du Plessis captained St Kitts and Nevis Patriots. Amla finished as the fourth highest run scorer but as (bad) luck would have it, neither de Villiers nor du Plessis had any great success. Du Plessis copped it particularly badly.

His team finished bottom of the table, with just two wins from ten games, but as the tournament was coming to an end he had a chance to escape their gloom. On July 7, all of South Africa's nationally contracted players were summoned home for CSA's annual awards. By the time du Plessis was done in South Africa, Patriots had two games left to play and were out of contention for the playoffs. He could easily have stayed at home but he insisted on returning. "There was never even a hint of not finishing the job he started," Eric Simons, Patriots' coach said. "That more than anything defined his personality as the leader."

Simons remembers du Plessis taking the results in his stride, even when they continued to not go his way. "He remained calm, analytical and always tried to find solutions. Those are important characteristics of any leader.

"He always had good thinking in the field and sound reasoning for the decisions he made. He read the opposition well and made plans with this insight. He has very good awareness on the field."

In South African colours, du Plessis had only showcased those skills in small doses, until now. At the CPL, de Villiers aggravated an elbow injury sustained through overuse. When he got back home, it was decided to first treat it conservatively with rest and cortisone, sitting out the New Zealand Tests but aiming to be back for the home ODIs and away Tests against Australia. But the healing did not proceed as hoped and instead required surgery that will sideline him until December.

Over to du Plessis. He was brought back into the Test XI after being dropped for the final fixture against England in January, and brought back as captain. He scored a century in Centurion to help South Africa to a series win against New Zealand. He scored another hundred in the second ODI, in Johannesburg earlier this month, on South Africa's way to a 5-0 whitewash of the No. 1-ranked ODI team. What happens if du Plessis makes a series-winning contribution in the Tests? Where does that leave him and de Villiers?

Faf du Plessis, AB de Villiers and Hashim Amla with the Deloitte Outstanding Contribution to South African Sport Award during the Virgin Active Sport Industry Awards in Johannesburg Getty Images

To say they are rivals may be going too far, because they are close as friends and have shared too much on the cricket field to view each other that way. But Simons is of the opinion only one of them should lead, although having not worked with de Villiers he cannot say who that should be. "I do not believe that the system of multiple captains is the correct one. A team needs a leader, and subconsciously it is confusing when that person changes from one format to the other. I am sure all the candidates have good credentials, so I would encourage a decision to be made to appoint a single leader," he said.

If South Africa agree, they will need to consider what Simons believes is the most important quality for a leader. "A captain of an national cricket team has got to want to do the job and be prepared to make the tough calls," he said.

De Villiers had long said he wants the job, even when Amla was given it ahead of him. Du Plessis also enjoys captaincy and has said it spurs on his performances and other aspects of his personality. "Captaincy brings the best out of me. I feel that I can drive the team and that I need to live everything I say every day and be the best me every day - on the field or off the field. I am a guy that likes to lead from the front. Mentally it puts me in a good space," he said.

Perhaps the same cannot be said of de Villiers. Although his numbers swell when he is charge - an ODI average of 65.92 as captain compared to 53.63 when not - de Villiers has never looked 100% comfortable in the role.

He has been extreme in his assessments, famously claiming he believed he took the best team in the world to the 2015 World Cup, a team he said would win the tournament, and then blaming himself every time South Africa lost. De Villiers' idea of being a team man is noble. He gives everything and expects his men to give everything back. He does not leave wriggle room for errors, mishaps or just plain bad luck. He wants to win so badly that he cannot deal with defeat.

Du Plessis' approach is more nuanced. He has already said he accepts South Africa will not emerge victorious from every series. He wants to see overall growth and he does not expect himself to be the only player who does the growing.

"I sensed that Faf does not define himself as a person by the success and failure of the team," Simons said. "He takes the role very seriously but realises that a bad game or performance does not suddenly make you a bad cricketer. This is very important in the high-profile leadership role of a captain. It allows logical thinking not to be clouded by emotion."

Du Plessis' clarity has already put him a step above de Villiers. In his public engagements, he tells it like it is. When Amla was left out of the second ODI, though he was recovering from an illness that kept him out of the first, du Plessis said that it was not his decision but that of the selectors and that he himself had wanted Amla to play. Du Plessis also addressed transformation openly - helped by the fact that the policy is now known to all - and said that the team is happier now that CSA has stated what its targets are openly.

De Villiers in contrast has often sent mixed messages. His workload/retirement saga was one example. His changing position on whether he wants to keep wicket is another. Even in his biography he did not come clean about what happened in the World Cup semi-final when Vernon Philander was included ahead of Kyle Abbott. It was an open secret that the decision was based on a directive from CSA. None of these things make de Villiers any less of a brilliant cricketer than he is, but they may point to one thing he cannot do as well as someone else: captain. And if South Africa want their best leader for the job, they may have to look to du Plessis.