Association football

Association football

Main article: Association football ball

Dimensions

Law 2 of the game specifies that the ball is an air-filled sphere with a circumference of 68–70 cm (27–28 in), a weight 410–450 g (14–16 oz), inflated to a pressure of 0.6 – 1.1 atmosphere (600 – 1,100 g/cm2) at sea level (8.5 lbs/sq in –15.6 lbs/sq in), and covered in leather or "other suitable material".^[1] The weight specified for a ball is the dry weight, as older balls often became significantly heavier in the course of a match played in wet weather. The standard ball is a Size 5, although smaller sizes exist: Size 3 is standard for team handball and Size 4 in futsal and other small-field variants. Other sizes are used in underage games or as novelty items.

[edit] Construction

A classic truncated icosahedron football

Glass football trophy

A truncated icosahedron (left) compared with an association football (soccer) ball

Most modern footballs are stitched from 32 panels of waterproofed leather or plastic: 12 regular pentagons and 20 regular hexagons. The 32-panel configuration is the spherical polyhedron corresponding to the truncated icosahedron; it is spherical because the faces bulge due to the pressure of the air inside. The first 32-panel ball was marketed by Select in the 1950s in Denmark. This configuration became common throughout Continental Europe in the 1960s, and was publicised worldwide by the Adidas Telstar, the official ball of the 1970 World Cup.
The familiar 32 panel soccer ball design is sometimes referenced to describe the truncated icosahedron archimedean solid, carbon buckyballs or the root structure of geodesic domes.

The official match ball of the 2006 FIFA World Cup

Older balls were usually stitched from 18 oblong non-waterproof leather panels, similar to the design of the modern volleyballs and Gaelic footballs, and laced to allow access to the internal air bladder. This configuration is still common.
The official FIFA World Cup football for Germany 2006 matches was the 14-panel Adidas +Teamgeist. It was made in Thailand by Adidas, who have provided the official match balls for the tournament since 1970, and is a "thermally bonded" machine-pressed ball, rather than a traditionally stitched one. Adidas will continue to supply the official football for the 2010 and 2014 World Cups.^[2]
Another ball with an innovative pattern is the 26-panel Mitre PRO 100T.
There are also indoor footballs, which are made of one or two pieces of plastic. Often these have designs printed on them to resemble a stitched leather ball.

[edit] Oldest

The oldest discovered football was discovered in the roof of Stirling Castle in 1981 ^[3] and is made of leather (possibly deer ^[4])and pig's bladder. It has a diameter of between 14-16cm, weighs 125 grams and is currently on display at the Smith Art Gallery and Museum ^[5] in Stirling, Scotland.

[edit] Child labour

About 80% of association footballs are made in Pakistan. 75% of these (60% of all world production)^[6] are made in the city of Sialkot. Child labour was commonly used in the production of the balls. In 1996, during the European championship, activists lobbied to end the use of child labour. This eventually led to the Atlanta Agreement, which seeks to reform the industry to eliminate the use of child labour in the production of balls.^[7] This also led to a centralisation of production, which on the one hand would make it easier for the Independent Monitoring Association for Child Labour (IMAC^[8]) - an organization created to watch over the Atlanta Agreement - to make sure no child labour occurred, on the other hand often forced workers to commute further to get to work. According to the Fédération Internationale de Football Association (FIFA), the problem of eliminating the use of child labour is extremely complex, and that FIFA itself has neither "the experience nor the means to eradicate this wide-reaching problem on its own.".^[9]

[edit] American and Canadian football

Early American footballs were essentially rugby balls, later redesigned to make them easier to throw. In this 1907 photo, Bradbury Robinson, who threw the first legal forward pass, demonstrates an "Overhand spiral—fingers on lacing"^[10]

In North America, the term football refers to a ball used to play American football or Canadian football (both of which developed from Rugby football). It is also referred to as a "pigskin", because of their early use of pig's bladder to cover the ball (see Medieval football).
Nearly a prolate spheroid, the ball is slightly pointed at the ends, unlike the more elliptical rugby ball. The purpose of this design is to make the ball the most efficient shape to facilitate the forward pass. The Canadian football is slightly less prolate than the American ball and has a closer resemblance to a rugby ball.
The ball is about 11 inches (28 cm) long and about 22 inches (56 cm) in circumference at the center. American and Canadian footballs have different size standards, but those standards do overlap, making it possible for one ball to be used in either sport. The exterior of the ball is made of leather, which is required in professional and collegiate football. Footballs used in recreation, and in organized youth football, may be made of rubber or plastic materials (the high school football rulebooks still allow the inexpensive all-rubber footballs, though they are less common than leather).
Leather panels are usually tanned to a natural brown color, which is usually required in professional leagues and collegiate play. At least one manufacturer uses leather that has been tanned to provide a "tacky" grip in dry or wet conditions. Historically, white footballs have been used in football games played at night so that the ball can be seen easier; however, this practice is no longer commonplace, as artificial lighting conditions have improved to the point where they are no longer necessary. At most levels of play (but not, notably, the NFL), white stripes are painted on each end of the ball, halfway around the circumference, to improve nighttime visibility. (The UFL uses a ball with lime-green stripes.) The XFL used a novel color pattern, a black ball with red curved lines in lieu of stripes, for its footballs; this design was redone in a brown color scheme for the Arena Football League in 2003.
The leather is usually stamped with a pebble-grain texture to help players grip the ball. Some or all of the panels may be stamped with the manufacturer's name, league or conference logos, signatures, and other markings.
Four panels or pieces of leather or plastic are required for each football. After a series of quality control inspections for weight and blemishes, workers begin the actual manufacturing process.

A modern American football

Two of the panels are perforated along adjoining edges, so that they can be laced together. One of these lacing panels receives an additional perforation and reinforcements in its center, to hold the inflation valve.
Each panel is attached to an interior lining. The four panels are then stitched together in an "inside-out" manner. The edges with the lacing holes, however, are not stitched together. The ball is then turned right side out by pushing the panels through the lacing hole.
A polyurethane or rubber lining called a bladder is then inserted through the lacing hole.
Polyvinyl chloride or leather laces are inserted through the perforations, to provide a grip for holding, hiking and passing the football.
Before play, the ball is inflated to an air pressure of 12.5–13.5 psi (86–93 kPa). The ball weighs 14–15 ounces (397–425 g).
According to NFL.com:^[11] The home club shall have 36 balls for outdoor games and 24 for indoor games available for testing with a pressure gauge by the referee two hours prior to the starting time of the game to meet with League requirements. Twelve (12) new footballs, sealed in a special box and shipped by the manufacturer, will be opened in the officials’ locker room two hours prior to the starting time of the game. These balls are to be specially marked with the letter "K" and used exclusively for the kicking game.

[edit] Rugby football

Richard Lindon and William Gilbert started making balls for Rugby school out of hand stitched, four-panel, leather casings and pigs’ bladders. The rugby ball's distinctive shape is supposedly due to the pig’s bladder though early balls were more plum shaped than oval. The balls varied in size in the beginning depending upon how large the pig’s bladder was.^[12]
Until 1870, rugby was played with a spherical ball with an inner-tube made of a pig's bladder. In 1870 Richard Lindon introduced rubber inner-tubes and because of the pliability of rubber the shape gradually changed from a sphere to an egg. In 1892 the RFU endorsed ovalness as the compulsory shape. The gradual flattening of the ball continued over the years.^[13]

A rugby league football, as used in the NRL.

A Gilbert rugby football as used in rugby union.

The introduction of synthetic footballs over the traditional leather balls, in both rugby codes, was originally governed by weather conditions. If the playing surface was heavy, the synthetic ball was used, as it didn't absorb water and become heavy. Eventually, the leather balls were phased out completely.

[edit] Rugby league

Rugby league is played with a prolate spheroid shaped football which is inflated with air.^[14] A referee will stop play immediately if the ball does not meet the requirements of size and shape.^[14] Traditionally made of brown leather, modern footballs are synthetic and manufactured in a variety of colours and patterns. Senior competitions should use light coloured balls to allow spectators to see the ball more easily.^[14] The football used in rugby league is known as "international size" or "size 5" and is approximately 27 cm long and 60 cm in circumference at its widest point. Smaller-sized balls are used for junior versions of the game, such as "Mini" and "Mod". A full size ball weighs between 383 and 440 grams. Rugby league footballs are slightly more pointed than rugby union footballs and larger than American footballs.
The Australasian National Rugby League and European Super League use balls made by Steeden. Steeden is also sometimes used as a noun to describe the ball itself.

[edit] Rugby union

The ball used in rugby union, usually referred to as a rugby ball, is a prolate spheroid essentially elliptical in profile. Traditionally made of brown leather, modern footballs are manufactured in a variety of colors and patterns. A regulation football is 28–30 cm (11–12 in) long and 58–62 cm (23–24 in) in circumference at its widest point. It weighs 410–460 grams (14.5–16.2 ounces) and is inflated to 65.71–68.75 kPa (or 9.5–10 psi).^[15]
In 1980, leather-encased balls, which were prone to water-logging, were replaced with balls encased in synthetic waterproof materials.^[13] The Gilbert Synergie was the match ball of the 2007 Rugby World Cup.