The Fascinating Art of Reverse Swing

Imagine that you are driving a car on a narrow road that is wide enough only for two vehicles. You see a speeding car, hurtling in from the opposite direction. It comes straight enough initially, respecting all traffic rules. However, at the last possible minute, it swerves towards you and you need either considerable skills or plain dumb luck to prevent a disaster. This scenario, in my opinion, is perfectly analogous to an encounter between a batsman and a wicked reverse-swinging yorker.

To appreciate the nuances of reverse swing, it is necessary to understand how conventional swing really works. Fast bowlers choose a side of the ball that is to be kept shiny at all times. This is accomplished through the application of liberal doses of sweat and saliva and constant rubbing on the pants of the bowler and fielders. The other side is left to its fate and becomes naturally rough (though it can be roughened unscrupulously, something that will be explained later in the article). After that, the laws of physics take over and run the show.

Air offers considerable resistance to the rough side and little to the shiny one. As a result, the trajectory of the ball does not remain straight and the ball deviates in the direction that the rough side faces. Hence, the bowler can trigger outswing and inswing by aligning the direction of the seam in the corresponding direction. Conventional swing is something that technically superior batsmen can predict and negotiate it by observing the seam position. What if the ball were to move in a direction radically opposite to the one it was supposed to and that too very late? This is the phenomenon which goes by the name of reverse swing and is something that most batsmen would rather not face.

The art of reverse swing is a relatively modern invention compared to the other guiles employed by fast bowlers. It is believed to have originated in Pakistan; a country that produces prodigious fast bowlers seemingly on demand. Sarfaraz Nawaz is credited as the first ever exponent of reverse swing. At Melbourne in 1979, Nawaz used it to devastating effect and bowled a freakish spell, taking 7 wickets for one run. Imran Khan carried the baton of reverse swing and passed it on to two bowlers who revolutionized the science of fast bowling: Wasim Akram and Waqar Younis

The England-Pakistan series of 1992 was a landmark one for it was the first time that reverse swing decided the fate of a Test series. Wasim and Waqar decimated the strong English batting line-up and shared 43 wickets between them. Voices started getting raised against this unorthodox art. The English media accused the two W’s of ball tampering and thus, of cheating. Javed Miandad, in his autobiography titled Cutting Edge says: “The England manager Mickey Stewart made a statement saying that he knew very well what the Pakistani bowlers were up to but he wasn’t going to say what it was. It was the classical English ploy when you say something without really saying it.” Even Wisden Cricketer’s Almanack, the Bible of cricket, published an article titled: “Pakistani bowling – fair or foul?”

With habituation, came acceptance and this strange but lethal form of bowling ceased to be considered as witchcraft. The English bowlers began studying and implementing it home conditions. Darren Gough was particularly effective with reverse swing and became the mainstay of the English attack through the 90’s. Reverse swing was one of the major reasons why the Ashes series of 2005 has come to be remembered by many as the greatest Test series of the modern era. Skilled and intelligent bowlers like Zaheer Khan, Lasith Malinga and Umar Gul use the reversing old ball to great effect in today’s batsman dominated game.

Does this unconventional movement of the cricket ball mean that the laws of physics are defied through sheer talent? The answer is a resounding no. In a nerd’s language, reverse swing is direct application of Bernoulli’s principle and the Magnus effect. A number of conditions need to be fulfilled to make a ball dart in late like a missile. First of all, for a ball to reverse, it has to be old. The number of overs needed before a ball starts reversing varies from place to place. In Pakistan, bowlers have been known to extract reverse swing as early as the tenth over; while in English conditions, as many as 40 overs may be required. Also, the fuller and faster a delivery is bowled, the better. Waqar Younis and Shoaib Akhtar in their pomp could bowl extremely quick and unplayable toe-crushing yorkers.

The explanation for the cause of reverse swing is not that mysterious. Clive During, in an article for the South African Cricket Action magazine, provides a very logical explanation. He states that when an old ball approaches 90 mph, the boundary layers become turbulent of their own accord: in other words, no seam is required to cause the turbulence. The seam in fact, plays the role of ‘ramping’ the turbulent layer off the ball. The sideways pressure gets reversed; consequently the layer on one side precedes the layer on the other side and the ball swings the other way. Hence, the idea is to generate turbulence in the boundary layer ahead of the seam, and in order to do this the bowler has to deliver the ball at a speed of which not many are capable.

In the 2005 Ashes, tall and strong bowlers like Flintoff and Harmison banged the ball very hard on the pitch, which wore it down faster. It could also be observed that English fielders always passed the ball to each other on the bounce. This sneakily modified ball then performed various tricks that bamboozled the Aussies. Before television cameras could cover every inch of the field, players were even known to make use of tools like soda bottle caps to aid reverse swing. Cricket greats like Derek Pringle and Allan Donald have gone so far as to say that ball-tampering should be legalized.

In this age of T-20, batsmen are testosterone-driven bullies while bowlers are increasingly being relegated to become just a support act. This transformation is not heartening because true cricket lovers like to see an even contest between bat and ball. I feel that tools like the reverse swing in the hands of capable bowlers will significantly restore the skewed balance. It is definitely more enjoyable to see stumps flying around courtesy of reverse swinging yorkers rather than mindless six-hitting on flat and insipid pitches!

Here is a compilation video of Waqar Younis wreaking havoc with reverse swing: