No man has won both 200m and 400m gold at the same championships since the great one, Michael Johnson in 1995.
Can Wayde van Niekerk double up this time? He breezed into the 400m final by running 44.22 over the weekend and that remains his stronger event.
Mind you when you can run the 100m in under 10 seconds, the 200m in under 20 seconds and the 400m in under 44 seconds you don't really have a weak event...
Van Niekerk is in heat three.