Based on branch nominations to date, businessperson Cyril Ramaphosa is the frontrunner for the key position. Whether he will accept the nomination is debatable.
Furthermore, Kgalema Motlanthe's inability to openly campaign for the ANC presidency may result in him being frozen out of the running altogether.
Ramaphosa has garnered nearly 2 000 nomination votes from provinces – with the vast majority coming from those keen on seeing Zuma return as ANC president for a second term.
"He remains an extremely popular person in the party but if he is getting the deputy's nod on his pedigree alone and not an attempt to rescue Zuma's image is the big talking point," says Ebrahim Fakir, political analyst at the Electoral Institute of Southern Africa.
But Ramaphosa isn't guaranteed a berth as deputy president of the ruling party based on his superior number of nominations.
There are myriad factors influencing the race for the deputy presidency.
The Congress of South African Trade Unions (Cosatu), for instance, have called for Motlanthe to be retained in Mangaung lest there be "long-term implications for unity" in the ANC. The federation has indicated he should be retained in the top six of the ANC to provide continuity.
Cosatu's secretary general Zwelinzima Vavi has openly criticised Zuma's leadership in the past and should Motlanthe decide not to run against Zuma for the top post, it is likely Vavi will lead a staunch campaign to see Motlanthe retained as number two.
So far Motlanthe has made it abundantly clear that he will not be a part of any backroom leadership deals.
His most common refrain during the lead up to this elective conference is that he will bow to the will of the ANC's branches, and if they decide he must stand for a particular position, he will do so.
"People are misunderstanding his campaign and what he's saying. He knows he will lose Mangaung, but he wants the ANC delegates to decide that and won't become part of any organised leadership. He's thus making a point on democratic processes and principles in the ANC," said Steven Friedman, director at the Centre for the Study of Democracy.
Motlanthe was nominated for deputy president by the Northern Cape. So technically Motlanthe would be staying true to his word if he were to throw his hat in the ring for second place.
Complicating matters further is Ramaphosa's unwillingness to stand against Motlanthe.
According to sources close to Ramaphosa, he said he will not stand for the deputy president position if it's against Motlanthe.
The businessperson's reluctance is said to be influenced by their close friendship and common history as former secretaries general of the National Union of Mineworkers (NUM).
Ramaphosa might feel obliged, like Motlanthe, to remain loyal to party processes.
It might prove difficult for the business mogul to resist the call by an overwhelming majority of ANC branches and could be swayed to stand – regardless of his challenger.
"It's simple. If it goes to a vote Ramaphosa will win hands down," says Friedman.
Fakir agrees: "There's an outside chance he could be returned as deputy, but it's looking unlikely. It's Cyril's to take if he wants it."
Besides the potential duel between Ramaphosa and Motlanthe, there is also the slim chance that other candidates for deputy presidency might find their way on to the ballot at Mangaung.
ANC treasurer general Matthews Phosa was nominated by the ANC Youth League and Limpopo province and mustered 385 provincial nominations altogether.
But Phosa would only ascend to the post in the unlikely event of Motlanthe toppling Zuma as party president.
He has been a vocal critic of the president's leadership style and further alienated himself from the pro-Zuma factions within the ANC as a supporter of ousted league president Julius Malema.
Another Zuma detractor up for the number two spot is Human Settlements Minister Tokyo Sexwale, who was chosen by several branches in Gauteng, Limpopo and the Eastern Cape, earning himself 419 nominations in total.
Among the candidates, Sexwale is the only one who has openly shown an interest in the deputy presidency and this may well count against him.
According to ANC tradition, it is considered vulgar to campaign openly for positions and Sexwale's naked ambition might backfire on him.
Like Phosa, Sexwale would only have a real chance at the deputy presidency should Motlanthe challenge Zuma in Mangaung.
"It is in nobody's interest at this stage – besides those wanting to change Zuma as president – to have either of them elected as [deputy president]. The only way either of them would be elcted is if both Motlanthe and Ramaphosa backed off and that's extremely unlikely at this stage," said Friedman.
Current ANC chairperson Baleka Mbete is also in the running after she was put forward as a deputy presidential candidate by the majority of ANC branches in the Free State.
But it would be extremely risky for Mbete to take up the nomination and challenge for the position. She was again nominated for ANC chairperson by the majority of branches in provinces that have also chosen Zuma, and she would need to keep the status quo to keep the position.
The most likely scenario for Sexwale, Phosa and Mbete would be their prospective votes falling to either Ramaphosa or Motlanthe, if the two square up Mangaung.
This would still translate into a landslide victory for Ramaphosa as branch nominations are directly translated into votes at Mangaung. Delegates who would have backed Mbete would most likely back Ramaphosa and those supporting Phosa and Sexwale are likely to throw their lot in with Motlanthe.