Reverse swing
Pioneers and notable practitioners of reverse swing have mostly been Pakistani fast bowlers. In the early days of reverse swing, Pakistani bowlers were suspected of ball tampering to achieve the conditions of the ball that allow reverse swing, but today they are considered simply to have been ahead of their time. Former Pakistan international Sarfraz Nawaz and Sikander Bakht were the founders of reverse swing during the late 1970s, and they passed the knowledge on to former team-mate Imran Khan,[1] who in turn taught the duo of Wasim Akram and Waqar Younis. The English pair of Andrew Flintoff and Simon Jones are also well known for the ability to reverse swing the ball having been taught by Troy Cooley.[2]. More recently, a destructive display of swing bowling was demonstrated by Dale Steyn during the test match between India and South Africa at Nagpur. Normal swing occurs mostly when the ball is fairly new. As it wears more, the aerodynamics of the asymmetry change and it is more difficult to extract a large amount of swing. When the ball becomes very old — around 40 or more overs old — it begins to swing towards the shine. This is known as reverse swing- which means a natural outswinger will become an inswinger and conversely, an inswinger into an outswinger.[3] In essence, both sides have turbulent flow, but here the seam causes the airflow to separate[clarification needed] earlier on one side. The result is always a swing to the side with the later separation, so the swing is away from the seam.
Reverse swing tends to be stronger than normal swing, and to occur late in the ball’s trajectory. This gives it a very different character from normal swing, and because batsmen experience it less often, they generally find it much more difficult to defend against. It is also possible for a ball to swing normally in its early flight, and then to reverse as it approaches the batsman. This can be done in two ways[citation needed]: one for the ball to reverse in the opposite direction to the original swing, giving it an “S” trajectory; and the other for it to reverse in the same direction making the swing even more pronounced. Either way it can be devastating for the batsman: in the first instance, he is already committed to playing one way, which is often the wrong way to play swing in the opposite direction; and in the second instance, his stance will have conformed to dealing with the degree of expected swing and could leave him vulnerable to being caught behind, LBW or bowled. Two back to back deliveries from Wasim Akram, one of each type, were considered to be the turning point of the 1992 World Cup Final.
