All Blacks in South Africa: Scott Robertson will need to be at sharpest to outwit Rassie Erasmus

Analysis - The All Blacks have touched down in South Africa for what coach Scott Robertson has described as the biggest challenge yet of his first season in charge. They face a rematch of last year's World Cup final, at the iconic venue of Ellis Park in Johannesburg before moving to their first ever test at Cape Town's DHL Stadium.

Here's the big talking points as rugby's greatest rivalry resumes this weekend:

Clash of the coaches

Robertson and Rassie Erasmus have shared history - they both played against each other as All Black and Springbok loose forwards, and now find themselves locking horns as coaches. They're both probably the most intriguing personalities involved in both teams and their wits are about to get put to the test, although since Erasmus has already won two World Cups, it's on Robertson to really deliver here.

Reshuffle

Leon MacDonald is gone as assistant, the details around which we're probably not going to know for sure for a while. What is for sure is that these tests may well show if it was a good move or not.

10-15 debates

Damian McKenzie turned on the juice in the All Blacks' last test, but the question mark over whether he can do it week in-week out is a pretty big one. He was able to unlock the Pumas' defence with ease at Eden Park, but it's going to be a lot tougher against a Bok defence that will be flying out of the line to pressure him into mistakes. So if that does happen, how quickly will Robertson turn to Beauden Barrett to fix that area?

The Springboks may well be better than they were last season

Due to them not being in Super Rugby anymore, there is a real air of mystery about the new names you see on the Bok team sheet. Sacha Feinberg-Mngomezulu is being touted as a generational first five, who is keeping out the likes of Handre Pollard and Manie Libbok. One of the main hallmarks of Erasmus's coaching style is constant innovation, taking the parts that worked in their tests with Ireland and the Wallabies, and sharpening them for this series.

Party at Tony Brown's

Erasmus isn't the only Springbok coach that Robertson used to play against. In fact, he played alongside Tony Brown as an All Black, but the former Otago man is now doing a very effective job as the Boks' attack coach. The most notable change Brown's made is getting the ball into the hands of Pieter-Steph du Toit and Siya Kolisi far more often and having the loose forwards running at mismatches out wide.

Home again in Cape Town

After the Ellis Park cauldron, the All Blacks will likely be happy to touch down in the Mother City, where the support for the team has always been very strong. So strong in fact, that's why SA Rugby has been rather reluctant to host the All Blacks there with their last visit being seven years ago.

Tight five shake ups

The All Blacks have lost Ethan de Groot for the two tests, however, Tamaiti Williams acquitted himself really well against the Pumas in a dominant All Black scrum. The rumour out of the Springbok camp is that Erasmus will name rookie loosehead Gerhard Steenekamp for the first test, as well as moving du Toit to lock to accommodate exciting number eight Ben-Jason Dixon. Meanwhile, Scott Barrett is set to return to the All Black second row after missing the Pumas' tests.

What happens if the All Blacks lose both?

Had it not been for the loss to the Pumas in Wellington, the pressure probably wouldn't be as high for this considering it's two tests against the world champions on their own patch. However, if the All Blacks don't kick on from their win at Eden Park, some serious questions should start being asked given just how hard it's going to get later on in the year with away tests in London, Dublin and Paris. The All Blacks aren't a development team, they should be playing fully formed rugby at all times.

Springboks v All Blacks

Kick-off: 3am Sunday 1 September (NZT)

Ellis Park, Johannesburg

Live blog coverage on RNZ Sport

Teams: TBC