Badminton hui xian(16)

Badminton is a racquet sport played by either two opposing players (singles) or two opposing pairs (doubles), who take positions on opposite halves of a rectangular court that is divided by a net. Players score points by striking a shuttlecock with their racquet so that it passes over the net and lands in their opponents' half of the court. A rally ends once the shuttlecock has struck the ground, and each side may only strike the shuttlecock once before it passes over the net.

Racquets
Badminton racquets are light, with top quality racquets weighing between 75 and 95 grams including the strings.[8][9] They are composed of many different materials ranging from carbon fibre composite (graphite reinforced plastic) to solid steel, which may be augmented by a variety of materials. Carbon fibre has an excellent strength to weight ratio, is stiff, and gives excellent kinetic energy transfer. Before the adoption of carbon fibre composite, racquets were made of light metals such as aluminum. Earlier still, racquets were made of wood. Cheap racquets are still often made of metals such as steel, but wooden racquets are no longer manufactured for the ordinary market, because of their excessive mass and cost. Nowadays, nanomaterials such as fullerene and carbon nanotubes are added to rackets giving them greater durability.

There is a wide variety of racquet designs, although the Laws limit the racquet size and shape. Different racquets have playing characteristics that appeal to different players. The traditional oval head shape is still available, but an isometric head shape is increasingly common in new racquets.

Strings
Badminton strings are thin, high performing strings in the range of about 0.62 to 0.73 mm thickness. Thicker strings are more durable, but many players prefer the feel of thinner strings. String tension is normally in the range of 80 to 160 N (18 to 36 lbf). Recreational players generally string at lower tensions than professionals, typically between 18 and 25 lbf (110 N). Professionals string between about 25 and 36 lbf (160 N).

It is often argued that high string tensions improve control, whereas low string tensions increase power.[10] The arguments for this generally rely on crude mechanical reasoning, such as claiming that a lower tension string bed is more bouncy and therefore provides more power. This is in fact incorrect, for a higher string tension can cause the shuttle to slide off the racquet and hence make it harder to hit a shot accurately. An alternative view suggests that the optimum tension for power depends on the player:[8] the faster and more accurately a player can swing their racquet, the higher the tension for maximum power. Neither view has been subjected to a rigorous mechanical analysis, nor is there clear evidence in favour of one or the other. The most effective way for a player to find a good string tension is to experiment.

Grip
The choice of grip allows a player to increase the thickness of his racquet handle and choose a comfortable surface to hold. A player may build up the handle with one or several grips before applying the final layer.

Players may choose between a variety of grip materials. The most common choices are PU synthetic grips or towelling grips. Grip choice is a matter of personal preference. Players often find that sweat becomes a problem; in this case, a drying agent may be applied to the grip or hands, sweatbands may be used, the player may choose another grip material or change his grip more frequently.

There are two main types of grip: replacement grips and overgrips. Replacement grips are thicker, and are often used to increase the size of the handle. Overgrips are thinner (less than 1 mm), and are often used as the final layer. Many players, however, prefer to use replacement grips as the final layer. Towelling grips are always replacement grips. Replacement grips have an adhesive backing, whereas overgrips have only a small patch of adhesive at the start of the tape and must be applied under tension; overgrips are more convenient for players who change grips frequently, because they may be removed more rapidly without damaging the underlying material.

Playing court dimensions

Badminton court, isometric viewThe court is rectangular and divided into halves by a net. Courts are usually marked for both singles and doubles play, although the laws permit a court to be marked for singles only. The doubles court is wider than the singles court, but both are the same length. The exception, which often causes confusion to newer players, is that the doubles court has a shorter serve-length dimension.


The full width of the court is 6.1 metres (20 ft), and in singles this width is reduced to 5.18 metres (17 ft). The full length of the court is 13.4 metres (44 ft). The service courts are marked by a centre line dividing the width of the court, by a short service line at a distance of 1.98 metres (6 ft 6 inch) from the net, and by the outer side and back boundaries. In doubles, the service court is also marked by a long service line, which is 0.76 metres (2 ft 6 inch) from the back boundary.

The net is 1.55 metres (5 ft 1 inch) high at the edges and 1.524 metres (5 ft) high in the centre. The net posts are placed over the doubles sidelines, even when singles is played.

There is no mention in the Laws of Badminton of a minimum height for the ceiling above the court. Nonetheless, a badminton court will not be suitable if the ceiling is likely to be hit on a high serve