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Swing bowling is a technique used for bowling in the sport of cricket. Practitioners are known as swing bowlers. Swing bowling is generally classed as a subtype of fast bowling.
The aim of swing bowling is to cause the ball to move in the air (or 'swing') whilst delivering mainly fast-paced balls to the batsman, in the hope that the change in the ball's flight path will deceive the batsman and cause them to play the ball incorrectly. Swing bowling is not to be confused with spin bowling, which involves bowling slow-pace balls which change direction primarily after making contact with the ground.
Swing bowling involves the use of a newer ball which is only slightly worn. The bowling side will continually polish one side of the ball by applying saliva and sweat to it as well as rubbing it against their clothing to shine it, whilst leaving the opposite side unshined. The speed of airflow over the rough and smooth sides of the ball will cause the ball to move in flight towards the rough side and away from the shiny side. Swing bowlers will often use a subtly altered grip on the ball to accentuate this effect.
The two main forms of swing are inswing, where the ball begins wider of the batsman and travels into the batsman's body, angling towards the stumps, and outswing, where the ball begins in line with the stumps but moves so that it is slightly wider of the stumps by the time it reaches the batsman. As the shiny side will also become worn over the course of play, swing bowling is usually effective when the ball is newer, with the older ball being more useful for spin bowling or other forms of fast bowling. However, there are other types of swing, such as reverse swing, which involve using a much more worn ball.
As swing bowling is heavily dependent on the condition of the ball, many ball tampering controversies have been related to it, where teams have tried to illegally alter the wear of the ball using materials such as sandpaper to produce additional swing.
The essence of swing bowling is to get the cricket ball to deviate sideways as it moves through the air towards or away from the batsman. To do this, the bowler makes use of six factors:
The asymmetry of the ball is encouraged by the constant polishing of one side of the ball by members of the fielding team, while allowing the opposite side to deteriorate through wear and tear. With time, this produces a marked difference in the aerodynamic properties of the two sides, causing the ball to move towards the rough side and away from the shiny side.
Both turbulent and laminar airflow contribute to swing. Air in laminar flow separates from the surface of the ball earlier than air in turbulent flow, so that the separation point moves toward the front of the ball on the laminar side. On the turbulent flow side it remains towards the back, inducing a greater lift force on the turbulent airflow side of the ball. The calculated net lift force is not enough to account for the amount of swing observed. Additional force is provided by the pressure-gradient force.
To induce the pressure-gradient force the bowler must create regions of high and low static pressure on opposing sides of the ball. The ball is then "sucked" from the region of high static pressure towards the region of low static pressure. The Magnus effect uses the same force but by manipulating spin across the direction of motion. A layer of fluid, in this case air, will have a greater velocity when moving over another layer of fluid than it would have had if it had been moving over a solid, in this case the surface of the ball. The greater the velocity of the fluid, the lower its static pressure.
When the ball is new the seam is used to create a layer of turbulent air on one side of the ball, by angling it to one side and spinning the ball along the seam. This changes the separation points of the air with the ball; this turbulent air creates a greater coverage of air, providing lift. The next layer of air will have a greater velocity over the side with the turbulent air due to the greater air coverage and as there is a difference in air velocity, the static pressure of both sides of the ball are different and the ball is both 'lifted' and 'sucked' towards the turbulent airflow side of the ball.
When the ball is older and there is an asymmetry in roughness the seam no longer causes the pressure difference, and can actually reduce the swing of the ball. Air turbulence is no longer used to create separation point differences and therefore the lift and pressure differences. On the rough side of the ball there are scratches and pits in the ball's surface. These irregularities act in the same manner as the dimples of a golf ball: they trap the air, creating a layer of trapped air next to the rough side of the ball, which moves with the surface of the ball. The smooth side does not trap a layer of air. The next layer of air outward from the ball will have a greater velocity over the rough side, due to its contact with a layer of trapped air, rather than solid ball. This lowers the static pressure relative to the shiny side, which swings the ball. If the scratches and tears completely cover the rough side of the ball, the separation point on the rough side will move to the back of the ball, further than that of the turbulent air, thereby creating more lift and faster air flow. This is why a new ball will swing more than an old ball. If the seam is used to create the turbulent air on the rough side, the tears will not fill as quickly as they would with laminar flow, dampening the lift and pressure differences.
Reverse swing occurs in exactly the same manner as conventional swing, despite popular misconception. Over time the rough side becomes too rough and the tears become too deep – this is why golf ball dimples are never below a certain depth, and so "conventional" swing weakens over time; the separation point moves toward the front of the ball on the rough side. When polishing the shiny side of the ball, numerous liquids are used, such as sweat, saliva, sunscreen, hair gel (which bowlers may apply to their hair before a game) and other illegal substances like Vaseline (applied to the clothing where the ball is polished). These liquids penetrate the porous surface of the leather ball. Over time the liquid expands and stretches the surface of the ball (which increases the surface area meaning more lift) and creates raised bumps on the polished side, due to the non-uniform nature of the expansion. The valleys between the bumps hold the air in the same manner as the tears on the rough side. This creates a layer of air over the shiny side, moving the separation point towards the back of the ball on the shiny side. The greater air coverage is now on the shiny side, giving rise to more lift and faster secondary airflow on that side. There is therefore lower static pressure on the shiny side, causing the ball to swing towards it, not away from it as in conventional swing.
The rough side tears hold the air more easily than the shiny side valleys, so to maintain the air within the valleys the initial air layer must have a very high velocity, which is why reverse swing is primarily, but not necessarily, achieved by fast bowlers. Due to the less static nature of the initial air layer it takes longer for the swing to occur, which is why it occurs later in the delivery. This is why conventional and reverse swing can occur in the same delivery.
Cold and humid weather are said to enhance swing. Colder air is denser and so may affect the differential forces the ball experiences in flight. When looking at humidity, changes between 0% and 40% humidity appear to have little to no effect on the ball's swing; yet, when approaching 100% humidity "condensation shock" has been observed enhancing the swing of the ball.
Typically, a swing bowler aligns the seam and the sides of the ball to reinforce the swing effect. This can be done in two ways:
The curvature of swing deliveries can make them difficult for a batsman to hit with his bat. Typically, bowlers more commonly bowl outswingers, as they tend to move away from the batsman, meaning he has to "chase" the ball to hit it. Hitting away from the batsman's body is dangerous, as it leaves a gap between the bat and body through which the ball may travel to hit the wicket. Also, if the batsman misjudges the amount of swing, he can hit the ball with an edge of the bat. An inside edge can ricochet on to the wicket, resulting in him being out bowled, while an outside edge can fly to the wicket-keeper or slip fielders for a catch.
An inswinger presents relatively fewer dangers to the batsman, but on some particular days can be devastating due to risk of being bowled or leg before wicket. Shane Bond was considered a great exponent of inswing bowling.
An inswinger combined with a yorker can be especially difficult for the batsman to defend against, especially if used as a surprise delivery after a sequence of outswingers.
There has been a distinct lack of left-arm swing bowlers in the game.Some of the most famous left-arm bowlers were Pakistan's Wasim Akram, India's Zaheer Khan, Australia's Alan Davidson and Sri Lanka's Chaminda Vaas.
Normal swing occurs mostly when the ball is fairly new. As it wears more, the aerodynamics of the asymmetry changes and it is more difficult to extract a large amount of swing. When the ball becomes very old – around 50 or more overs old – it begins to swing towards the shine. It is mainly helpful for bowlers in Test matches. This is known as reverse swing, meaning that a natural outswinger will become an inswinger and vice versa. However, the new ball may reverse its trajectory if the speed is high (more than 90 mph). This is also called as contrast swing or reverse swing.In essence, both sides of a cricket ball have turbulent flow, but in reverse swing, the seam causes the airflow to separate earlier on one side. The side of the ball that has been shined experiences quicker airflow, while on the other side, the rougher surface disrupts the airflow, slowing that side of the ball down. This causes the ball to swing either outwards or inwards, depending on how it has been released from the hand when bowled, with the ball moving towards the side on which the ball is shined.
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 alter its swing as it approaches the batsman. This can be done in two waysone for the ball to reverse its direction of swing, giving it an 'S' trajectory: the other is for it to adopt a more pronounced swing in the same direction in which the swing is already curving; either alteration can be devastating for the batsman. In the first instance, he is already committed to playing the swing one way, which will be the wrong way to address swing which is suddenly coming from the opposite direction: in the second instance, his stance will be one which is appropriate for the degree, or extent, of the expected swing, and which could suddenly leave him vulnerable to LBW, being caught behind, or bowled. Two consecutive deliveries from Wasim Akram, one of each type, were considered to be the turning point of the 1992 World Cup Final.
Pioneers and notable practitioners of reverse swing have mostly been Pakistani fast bowlers. In the early days of reverse swing, Pakistani bowlers were accused of ball tampering to achieve the conditions of the ball that allow reverse swing. According to Shaharyar Khan, reverse swing was invented by Salim Mir, who played for the Punjab Cricket Club in Lahore and taught it to his team-mate Sarfraz Nawaz.Sarfraz Nawaz introduced reverse swing into international cricket during the late 1970s, and passed their knowledge on to their team-mate Imran Khan, who in turn taught the duo of Wasim Akram and Waqar Younis. The English pair of Andrew Flintoff and Simon Jones, having been taught by Troy Cooley and the Indian bowlers like Zaheer Khan and Ajit Agarkar, were also well known for the ability to reverse swing, among many others. Bowlers tend to disguise the direction of reverse swing by running up starting with the opposite hand before switching hands and covering the ball for as long as possible before release. Neil Wagner utilizes this to show the ball is reversing, but disguises the direction of swing.
Playing swing bowling is considered to be a hallmark of a batsman's skill.
Firstly, a batsman needs good eye reflexes which are considered to be a key skill when facing swing bowling. Secondly, a batsman often needs to anticipate beforehand what the ball will do and adjust accordingly to play swing bowling. This can be done by observing the bowler's grip and action (which may have a marked difference depending on which type of swinger is to be delivered), by observing the field set, which may depend on the types of deliveries expected (as a rule outswingers will have more slips assigned) or by means of prior knowledge of the bowler; many can bowl or are proficient in only one type of swing. Traditional methods include the batsmen playing the ball as late as possible, and not playing away from the body. Other effective measures for combating swing bowling include standing well outside the crease, thus giving the ball less time to swing; and guessing the direction of swing based on the seam position observed in the ball's flight.
Controversy regarding reverse swing has never left modern cricket, as the Pakistani team was accused of ball tampering by the Australian umpire Darrell Hair during the fourth test against England in 2006 when the ball began to reverse swing after the 50th over.His co-umpire Billy Doctrove supported him. A hearing subsequently found that there was insufficient evidence to convict anyone of ball tampering.
Leg spin is a type of spin bowling in cricket. A leg spinner bowls right-arm with a wrist spin action. The leg spinner's normal delivery causes the ball to spin from right to left in the cricket pitch when the ball bounces. For a right-handed batsman, that is away from the leg side, and this is where it gets the name leg break, meaning it breaks away from the leg. The turn is mostly when the ball pitches.
In the game of cricket, a googly refers to a type of delivery bowled by a right-arm leg spin bowler. The googly is a variation of the typical leg spin type of delivery, in that the cricket ball is presented from the bowler's hand in such a way that once the ball pitches, it deviates in the opposite direction of a leg spinning type of delivery. It has also been colloquially and affectionately referred to as the wrong'un, Bosie or Bosey, with those latter two eponyms referring to Bernard Bosanquet, the bowler who initially discovered and began using the googly.
Bowling, in cricket, is the action of propelling the ball toward the wicket defended by a batter. A player skilled at bowling is called a bowler; a bowler who is also a competent batter is known as an all-rounder. Bowling the ball is distinguished from throwing the ball by a strictly specified biomechanical definition, which restricts the angle of extension of the elbow. A single act of bowling the ball towards the batsman is called a ball or a delivery. Bowlers bowl deliveries in sets of six, called an over. Once a bowler has bowled an over, a teammate will bowl an over from the other end of the pitch. The Laws of Cricket govern how a ball must be bowled. If a ball is bowled illegally, an umpire will rule it a no-ball. If a ball is bowled too wide of the striker for the batsman to be able to play at it with a proper cricket shot, the bowler's end umpire will rule it a wide.
Fielding in the sport of cricket is the action of fielders in collecting the ball after it is struck by the batsman, to limit the number of runs that the batsman scores and/or to get the batsman out by catching the ball in flight or by running the batsman out. There are a number of recognised fielding positions, and they can be categorised into the offside and leg side of the field. Fielding generally involves preventing the ball from going to or over the edge of the field, and getting the ball to either wicket as quickly as possible.
This is a general glossary of the terminology used in the sport of cricket. Where words in a sentence are also defined elsewhere in this article, they appear in italics. Certain aspects of cricket terminology are explained in more detail in cricket statistics and the naming of fielding positions is explained at fielding (cricket).
A cricket ball is a hard, solid ball used to play cricket. A cricket ball consists of a cork core wound with string then a leather cover stitched on, and manufacture is regulated by cricket law at first-class level. The trajectory of a cricket ball when bowled, through movement in the air, and off the ground, is influenced by the action of the bowler and the condition of the ball and the pitch, while working on the cricket ball to obtain optimal condition is a key role of the fielding side. The principal method through which the batsman scores runs is by hitting the ball, with the bat, into a position where it would be safe to take a run, or by directing the ball through or over the boundary. Cricket balls are harder and heavier than baseballs.
Pace bowling is one of two main approaches to bowling in the sport of cricket, the other being spin bowling. Practitioners of pace bowling are usually known as fast bowlers, quicks, or pacemen. They can also be referred to as a seam bowler, a swing bowler or a fast bowler who can swing it to reflect the predominant characteristic of their deliveries. Strictly speaking, a pure swing bowler does not need to have a high degree of pace, though dedicated medium-pace swing bowlers are rarely seen at Test level these days.
Seam bowling is a bowling technique in cricket whereby the ball is deliberately bowled on to its seam, to cause a random deviation when the ball bounces. Practitioners are known as seam bowlers or seamers.
An arm ball is a type of delivery in cricket. It is a variation delivery bowled by an off spin bowler or slow left-arm orthodox bowler. It is the finger spin equivalent of a wrist spinner's slider or zooter.
An outswinger is a type of delivery in the sport of cricket. It is bowled by swing bowlers.
An inswinger is a type of delivery in the sport of cricket. It is bowled by swing bowlers.
An off cutter is a type of delivery in the game of cricket. It is bowled by fast bowlers.
In the sport of cricket there are two broad categories of bowlers: pace and spin. Pace bowlers rely mostly on the speed of the ball to dismiss batsmen, whereas spin bowlers rely on the rotation of the ball.
In the sport of cricket, a slower ball is a slower-than-usual delivery from a fast bowler. The bowler's intention is to deceive the batsman into playing too early so that he either misses the ball completely or hits it high up in the air to offer an easy catch. It is analogous to a changeup in baseball.
Law 41 of the Laws of Cricket covers unfair play. This law has developed and expanded over time as various incidents of real life unfair play have been legislated against.
A delivery or ball in cricket is a single action of bowling a cricket ball toward the batsman. These terms can also refer to the events that occur after the ball is bowled while the ball is not dead.
Wrist spin is a type of bowling in the sport of cricket. It refers to the cricket technique and specific hand movements associated with imparting a particular direction of spin to the cricket ball. The other spinning technique, usually used to spin the ball in the opposite direction, is finger spin. Wrist spin is bowled by releasing the ball from the back of the hand, so that it passes over the little finger. Done by a right-handed bowler, this imparts an anticlockwise rotation to the ball, as seen from the bowler's perspective; a left-handed wrist spinner rotates the ball clockwise.
Finger spin is a type of bowling in the sport of cricket. It refers to the cricket technique and specific hand movements associated with imparting a particular direction of spin to the cricket ball. The other spinning technique, generally used to spin the ball in the opposite direction, is wrist spin. Although there are exceptions, finger spinners generally turn the ball less than wrist spinners. However, because the technique is simpler and easier to master, finger spinners tend to be more accurate.
In cricket a bowling machine is a device which enables a batsman to practice and to hone specific skills through repetition of the ball being bowled at a certain length, line and speed. It can also be used when there is no-one available to bowl, or no one of the desired style or standard.
In ball sports, topspin is a property of a ball that rotates forwards as it is moving. Topspin on a ball propelled through the air imparts a downward force that causes the ball to drop, due to its interaction with the air. Topspin is the opposite of backspin.