Well, not much really. South Africa is likely to make it through to the semifinals even if it loses today. England will have to beat the Proteas by 207 runs or more to eliminate the Temba Bavuma-led side and help Afghanistan qualify.
A win for South Africa will ensure it qualifies as the top team from Group B, ahead of Australia. But with India and New Zealand qualifying from Group A, it doesn’t really matter who you face in the last-four stage. Still, there is something like winning momentum and all that, which apparently plays a vital role in ‘big’ tournaments.