Although England's more positive and aggressive approach with the bat has been crucial to their success under Ben Stokes and Brendon McCullum, former captain Sir Alastair Cook believes their ability to take 20 wickets, particularly away from home, is the "real big change".
Since Stokes and McCullum took charge last summer, England have bowled out their opponents in all 21 innings, with South Africa not needing to bat a second time in England's sole defeat by an innings and 12 runs at Lord's last August.
And Cook has been hugely impressed by the way England have bowled and the fact that, after securing a 276 run win over New Zealand in Mount Maunganui, they have now taken 20 wickets in four consecutive Tests away from home.
