Cricket ball
A
cricket ball is a hard, solid
ball used to play
cricket.
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 all limited overs cricket where coloured
clothing is worn.
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
[54560]. 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.
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.
Condition of a cricket ball
A new, highly polished ball is used at the start of each
innings in a match.A cricket ball may not be
replaced except under specific conditions described in the
Laws of Cricket:
- If the ball becomes damaged or lost.
- If the condition of the ball is illegally modified by a
player.
- In Test cricket, after 80 overs,
the captain of the bowling side has the option to take a new
ball.
- In One Day Internationals, there is a mandatory change of the
ball at the start of the 35th over of each innings. The replacement
will be a clean used ball, not a new ball. This rule was introduced
in June 2007[54561]
The ball is not replaced if it is hit into the crowd - the crowd
must return it. If the ball is damaged, lost, or illegally
modified, it will be replaced by a
used ball in similar
condition to the replaced ball. A
new ball can only be
used after the specified minimum number of overs have been bowled
with the old one.
Because a single ball is used for an extended period of play, its
surface wears down and becomes rough. The
bowlers will polish it whenever they can -
usually by rubbing it on their trousers, producing the
characteristic red stain that can often be seen there. However,
they will usually only polish one side of the ball, in order to
create 'swing' as it travels through the air. They may apply
natural substances (i.e. saliva or sweat) to the ball as they
polish it.
The seam of a cricket ball can also be used to produce different
trajectories through the air, with the technique known as
swing bowling, or to produce sideways movement
as it bounces off the
pitch, with the
technique known as
seam bowling.
Since the condition of the cricket ball is crucial to the amount of
movement through the air a bowler can produce, the laws governing
what players may and may not do to the ball are specific and
rigorously enforced. The
umpires
will inspect the ball frequently during a match. It is illegal for
a player to:
- rub any substance apart from saliva or sweat onto the ball
- rub the ball on the ground
- scuff the ball with any rough object, including the
fingernails
- pick at or lift the seam of the ball.
Despite these rules, it can be tempting for players to gain an
advantage by breaking them. There have been a handful of incidents
of so-called
ball tampering at the
highest levels of cricket, involving players such as Pakistani fast
bowler
Waqar Younis and former England
captain
Mike Atherton.
A new cricket ball is harder than a worn one, and is preferred by
fast bowlers because of the speed and
bounce of the ball as it bounces off the pitch. Older balls tend to
spin more as the roughness grips the pitch more when the ball
bounces, so
spin bowlers prefer to use
a worn ball. Uneven wear on older balls may also make
reverse swing possible. A
captain may delay the request for a new ball if he prefers to have
his spin bowlers operating, but usually asks for the new ball soon
after it becomes available.
Dangers of cricket balls
Cricket balls are notoriously hard and potentially lethal, hence
today's batsmen and close fielders often wear protective headgear.
Raman Lamba was killed 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.
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), digital (fingers
and toes) and testicular.
Cricket ball swing
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.
Alternatives to cricket balls
Sometimes alternatives to a real cricket ball may be preferred for
reasons of safety, practice, availability and cost. Examples
include a
tennis ball (most favoured) or
a plastic version of the cricket ball, known as an
Incrediball.
Many casual players use a tennis ball wrapped in layers of some
type of
adhesive tape (often
electrical tape), which makes the relatively
soft tennis ball harder and smoother. This is commonly referred to
as a
tape ball. A common variant is to
tape only half the tennis ball, to provide two different sides and
make it easy to bowl with prodigious amounts of
swing.
See also
References
- Gollapudi, Nagraj. 'It's illegal, isn't it?' .
25 August 2008.
http://content-rsa.cricinfo.com/england/content/story/366225.html?CMP=NLC-DLY
(accessed August 26, 2008).
Notes
- [1]
- [2]
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