Cricket Ball:



A cricket ball is a hard, solid ball used to play cricket. Constructed of cork and leather, a cricket ball is heavily regulated by cricket law at first class level. The manipulation of a cricket ball, through employment of its various physical properties, is the staple component of bowling and dismissing batsmen – movement in the air, and off the ground, is influenced by the condition of the ball and the efforts of the bowler, while working on the cricket ball to obtain an optimum condition is a key role of the fielding side. The cricket ball is the principal manner through which the batsman scores runs, by manipulating the ball into a position where it would be safe to take a run, or by directing the ball through the boundary.
In Test cricket and most domestic games that spread over a multitude of days, the cricket ball is traditionally coloured red. In many one day cricket matches, the ball is coloured white. Training balls of white, red and pink are also common, and wind balls and tennis balls in a cricket motif can be used for training or unofficial cricket matches. During cricket matches, the quality of the ball changes to a point where it is no longer usable, and during this decline its properties alter and thus influence the match. Altering the state of the cricket ball outside the permitted manners designated in the rules of cricket is prohibited during a match, and 'ball tampering' has resulted in numerous controversies.
Cricket balls, weigh between 155.9 and 163.0 grams, are known for their hardness and for the risk of injury involved when using them. The danger of cricket balls was a key motivator for the introduction of protective equipment. Injuries are often recorded in cricket matches due to the ball, and a small number of fatalities have been recorded or attributed to cricket balls.




Manufacture


Cricket balls are made from a core of cork, which is layered with tightly wound string, and covered by a leather case with a slightly raised sewn seam. In a top-quality ball suitable for the highest levels of competition, the covering is constructed of four pieces of leather shaped similar to the peel of a quartered orange, but one hemisphere is rotated by 90 degrees with respect to the other. The "equator" of the ball is stitched with string to form the ball's prominent seam, with a total of six rows of stitches. The remaining two joins between the leather pieces are stitched internally. Lower-quality balls with a 2-piece covering are also popular for practice and lower-level competition due to their lower purchase cost.
For men's cricket, the ball must weigh between 5.5 and 5.75 ounces (155.9 and 163.0 g) and measure between 8 13/16 and 9 in (224 and 229 mm) in circumference. Balls used in women's and youth matches are slightly smaller.




White balls are used in many limited overs cricket matches, especially those involving floodlights (day/night games). This is because a red ball under yellow floodlights takes on a brownish color which is very similar to the color of the pitch.
Cricket balls are traditionally dyed red, and red balls are used in Test cricket and First-class cricket. White balls were introduced when one-day matches began being played at night under floodlights, as they are more visible at night. Professional one-day matches are now played with white balls, even when they are not played at night. Other colours have occasionally been experimented with, such as yellow and orange for improved night visibility, but the colouring process has so far rendered such balls unsuitable for professional play because they wear differently to standard balls. A pink ball was used for the first time in an international match in July 2009 when the England Women's team defeated Australia at Wormsley [2]. The white ball has been found to swing a lot more during the first half of the innings than the red ball and also deteriorates more quickly, although manufacturers claim that white and red balls are manufactured using the same methods and materials.[1]


Since the invention of 20-20 a lighter,softer white ball has been used. It has been designed to fit the faster format of the game and all white balls are said to be able to be hit a maximum of 29.5 metres further than the standard test ball. It travels at a greater speed through the air, and is therefore tailored to the needs of ODI and 20-20. It increased strike rate and the amount of sixes in the game.
Cricket balls are expensive. As of 2007, the ball used in first class cricket in England has a recommended retail price of 70 pounds sterling. In test match cricket this ball is used for a minimum of 80 overs (theoretically five hours and twenty minutes of play). In professional one day cricket, at least two new balls are used for each match. Amateur cricketers often have to use old balls, or cheap substitutes, in which case the changes in the condition of the ball may not be experienced in the same manner as that which occurs during an innings of professional cricket.
All ODI matches are played with Kookaburra balls but Test Matches in India are played with SG cricket balls. And when England hosts a International test match, they use “Duke cricket balls” whereas in all other Test Matches, Kookaburra balls comes in. [2]
During 1996 World Cup both umpire had a ball of their each when an one day International was played. Umpires switch between main umpire to leg umpire after every over and they used to give their ball to the fielding team, just to bowl six legal balls and used to take it back when the over finished. Same did the other umpire… & that is how ODI cricket was played at that time, purely because white balls gets dirty fairly quickly.[3] hi


Dangers of cricket balls






A used cricket ball
Cricket balls are notoriously hard and potentially lethal, hence today's batsmen and close fielders often wear protective headgear. Raman Lamba died when hit on the head while fielding at forward short leg in a club match in Bangladesh. Only two other cricketers are known to have died as a result of on-field injuries in a first-class fixture. Both were hit while batting: George Summers of Nottinghamshire on the head at Lord's in 1870; and Abdul Aziz, the Karachi wicket-keeper, over the heart in the 1958-59 Quaid-e-Azam final. Ian Folley of Lancashire, playing for Whitehaven in 1993, died after being hit.
Frederick, Prince of Wales is often said to have died of complications after being hit by a cricket ball, although in reality this is not true — although he was hit in the head by one, the real cause of his death was a burst abscess in a lung. Glamorgan player Roger Davis was almost killed by a ball in 1971 when he was hit on the head while fielding. The Indian batsman Nariman Contractor had to retire from the game after being hit by a ball on the head in the West Indies.
Indian Cricketer, Raman Lamba died of a cricket ball hit on his head in a club match in Dhaka. Lamba was fielding at short-leg without wearing a helmet, and the ball struck by batsman Mehrab Hossain hit him hard on his head and rebounded to wicket-keeper Khaled Mashud.
A cricket umpire died in 2009 in South Wales after being hit on the head by a ball thrown by a fielder.[4]
Numerous injuries are reported to health institutions, worldwide, in relation to cricket ball injuries including: occular (with some players having even lost eyes), cranial (head), dental (teeth), digital (fingers and toes) and testicular.


Cricket ball swing


See also: Swing bowling
The key to making a cricket ball swing is to cause a pressure difference between the two sides of the ball. The air pressure depends on the flow of air over each side of the ball. Swing is generated when bowlers, by accident or design, disrupt the flow of air over one side of the ball. Normal swing is achieved by keeping one side of the ball polished smooth and shiny, and delivering the ball with the polished side forward, and the seam angled in the direction of desired swing. The outswinging delivery moves away from the right-handed batsman, while the inswinger moves in towards him. Normal swing is achieved by maintaining laminar boundary layer air-flow on the shiny side whilst creating turbulent flow on the seam side. These deliveries, particularly the outswinger, are the bread and butter of opening bowlers who get to use the ball while it is still new. Reverse swing is very different from conventional swing. Although the seam is oriented in the same way as for an outswinger and the action is the same, the rough side of the ball is to the fore, and the ball moves in to the batsman like an inswinger. Reverse swing is achieved when the ball is bowled very fast. In this case the air flow will become turbulent on both sides before it reaches the seam.


                                            By: AMEYA DEVDATTA SANGEP