Ever wondered what it was like to face Mitchell Johnson?
Well, if you're feeling brave, you can step in and face him in the nets. If you're not, you can simply check out this video uploaded by the ICC, which shows the speed that he generates as he comes in to bowl.
Using an advanced simulator, batsmen can watch footage of Johnson (and other elite bowlers) running in to bowl, while a bowling machine fires the ball out at the point of release at the same speed as you could expect him to bowl.
In Johnson's case, that means at speeds in excess of 90 mph, which allows for just under half a second to react.
Given you need to make a judgement on line, length and move your feet and bat accordingly, you can see why batsmen from England and South Africa have struggled.