South Africa carry a 2-1 series lead and the number one ranking into the fourth and final Rugby's Greatest Rivalry Test against New Zealand at the M&T Bank Stadium in Baltimore on Saturday.
The Springboks currently hold a 2.43-rating-point advantage over the All Blacks — 94.33 to 91.90 — but that cushion could swing dramatically depending on the result. A South African win by more than 15 points would extend the gap to 4.70 points, their largest buffer over New Zealand during the series; a win by 15 or fewer would leave them 3.94 points clear. A draw keeps South Africa on top but costs them 0.24 rating points. Either way, the Springboks cannot finish the series lower than second.
New Zealand need a win to reclaim top spot, which they held briefly after the opening Test victory at Ellis Park before dropping back to second following their defeat in Cape Town. An All Blacks win of any margin returns them to number one, while a victory by more than 15 points would give them a 1.30-point cushion. With the Rivalry Trophy split between the two sides, a New Zealand win also means each nation retains one half of the magnetised two-part trophy.
Baltimore hosts its first Test match since the USA defeated Canada 12-7 there in 1978. The Springboks have played three previous Tests on US soil — wins over the USA in 1981 and 2001, and a 22-20 loss to Wales in Washington DC in 2018.