With Root shelling AB and Anderson returning the favour with Amla, England missed a great chance to have SA 200-4 prior to the new ball. Game on.
Now 350 odd for 3 and the follow on if pretty much a formality. It's up to England tomorrow to get through SA and protect what lead they have left. The longer SA bat the more limited Englands chance of having a dash 3rd innings. If SA bat 2 sessions for another 150 then England will only have a 130 lead and 4 sessions to make something happen. At best they will have to bat 1.5 sessions even then to put up a decent total. SA get any closer or take any longer and the last day could be very dull.
We need the pitch to fall apart pretty quickly to make this test interesting. It's not showing any signs so far.