Golf ball

From Wikipedia, the free encyclopedia

A golf ball is a ball designed to be used in the game of golf.

A golf ball beside a hole

Under the Rules of Golf, a golf ball weighs no more than
1.620 oz (45.93 grams), has a diameter not less than 1.680 in
 (42.67 mm), and performs within specified velocity, distance, and symmetry limits.
 Like golf clubs, golf balls are subject to testing and approval by the
 Royal and Ancient Golf Club of St Andrews and the United States Golf Association,
 and those that do not conform with regulations may not be used in competitions 

History

Wooden balls were the first used golf balls until the early 17th century, when the featherie ball added
a new and exciting feature to the game of golf. A featherie is a hand sewn leather pouch stuffed withchicken or
 goose feathers and coated with paint.
Enough feathers to fill a top hat were boiled and placed in the pouch.
 As the ball cooled, the feathers would expand and the hide would shrink,
 making a compact ball. If there were openings in the cowhide, stitchings were used to close them up.

Due to its superior flight characteristics,
the featherie remained the standard ball for more than two centuries.
 Despite this there were drawbacks.
 An experienced ball maker could only make a few balls in one day, so they were expensive.
 A single ball would cost between 2 shillings and sixpence and 5 shillings,
 which is the equivalent of 10 to 20 US dollars today.^[1] Also,
 it was hard to make a perfectly spherical ball, and because of this, the ball often flew irregularly.
When playing in wet weather,
the stitches in the ball would rot, and the ball could split open after hitting a hard surface.

In 1848, the Rev. Dr Robert Adams Paterson
(sometimes spelt Patterson) invented the gutta-percha ball (or guttie).^[2][3]
The gutta was created from dried sap of a Sapodilla Tree.
The sap had a rubber-like feel and could be made round by heating and shaping it while hot.
 Accidentally,
it was discovered that defects in the sphere from knicks and scrapes of normal use,
 could provide a ball with a truer flight than a pure sphere. Thus,
makers started creating intentional defects in the surface by
 hammering the ball to give it an evenly dimpled shape which
 would cause the ball to have a more consistent ball flight.
 Because gutties were cheaper to produce and could be
 manufactured with textured surfaces to improve their aerodynamic qualities,
they replaced feather balls completely within a few years.^[4]

In the 20th century,
multi-layer balls were developed, first as wound balls consisting of
a solid or liquid-filled core wound with a layer of rubber thread and a thin outer shell.
This idea was first discovered by Coburn Haskell of Cleveland, Ohio in 1898.
Haskell had driven to nearby Akron to keep a golf date with Bertram Work, then superintendent of B.F.
Goodrich.
 While he waited for Work at the plant, Haskell idly wound a long rubber thread into a ball.
When he bounced the ball, it flew almost to the ceiling.
 Work suggested Haskell put a cover on the creation, and that was the birth of the 20th century golf ball.
 The design allowed manufacturers to fine-tune the length, spin and "feel" characteristics of balls.
 Wound balls were especially valued for their soft feel, and continued to be popular until the early years
of the 21st century.^[5]

Modern balls usually consist of several layers of various synthetic materials like surlyn or urethane blends.
 They are usually classified as two-piece, three-piece,
 or four-piece ball according to the number of layers. They come in a great variety
of playing characteristics to suit the needs of golfers of different abilities.

Regulations

The current regulations mandated by the R&A and the USGA state that diameter of the
golf ball cannot be any smaller than 1.680 inches.
The maximum velocity of the ball may not exceed 250 feet per second (76 m/s)
under test conditions and the weight of the ball may not exceed 1.620 ounces.

Until 1990, it was permissible to use balls of no less than
 1.62 inches in diameter in tournaments under the jurisdiction of the R&A

Aerodynamics

When a golf ball is hit, the impact, which lasts less than a millisecond, determines the ball’s velocity, launch angle and spin rate, all of which influence its trajectory (and its behavior when it hits the ground).

A ball moving through air
experiences two major aerodynamic forces,
 lift and drag. Dimpled balls fly farther than non-dimpled balls due to the combination of two effects:

First, the dimples on the surface of a golf ball cause the boundary layer on the upstream
 side of the ball to transition from laminar to turbulent.
 The turbulent boundary layer is able to remain attached to the surface of
the ball much longer than a laminar boundary and so creates a narrower, low pressure,
 wake and hence less pressure drag. The reduction in pressure drag causes the ball to travel further.

Second, backspin generates lift by deforming the airflow around the ball,
in a similar manner to an airplane wing.
 This is called the Magnus effect.
Backspin is imparted in almost every shot due to the golf club's loft
(i.e., angle between the clubface and a vertical plane).
 A backspinning ball experiences an upward lift force
 which makes it fly higher and longer than a ball without spin.[1]
 Sidespin occurs when the clubface is not aligned perpendicularly to the direction of swing,
leading to a lift force that makes the ball curve to one side or the other.
Unfortunately the dimples magnify this effect as well as
 the more desirable upward lift derived from pure backspin.
 (Some dimple designs are claimed to reduce sidespin effects.)

To keep the aerodynamics optimal, the golf ball needs to be clean,
 in order to avoid any impediments to the aerodynamic effect of the ball.
Thus, it is advisable that golfers frequently wash balls. Golfers can wash balls manually,
but mechanical ball washers are also available.

Design

These two balls are disclosed in U.S. Patent 4,560,168. These two balls are easily made with a two-piece mould. Since there is no dimple located on any of the slash-dotted circles (one is marked red), the mould can be two hemispheres.

Dimples first became a feature of golf balls when English engineer and manufactuer
 William Taylor registered a patent for a dimple design in 1905.
 Other types of patterned covers were in use at about the same time,
including one called a "mesh" and another named the "bramble",
 but the dimple became the dominant design due to "the superiority of the dimpled cover in flight".^[7]

Most golf balls on sale today have about 250 – 450 dimples, though there have been balls with more than 500 dimples^{[citation needed]}. The record holder was a ball with
1,070 dimples — 414 larger ones (in four different sizes) and 656 pinhead-sized ones.
 All brands of balls, except one, have even-numbered dimples^{[citation needed]}. The only odd-numbered ball on the market is a ball with 333 dimples, called the Srixon AD333^{[citation needed]}.

Officially sanctioned balls are designed to be as symmetrical as possible.
 This symmetry is the result of a dispute that stemmed from the Polara,
a ball sold in the late 1970s that had six rows of normal dimples
on its equator but very shallow dimples elsewhere.
This asymmetrical design helped the ball self-adjust
 its spin-axis during the flight. The USGA refused to sanction it for tournament play and, in 1981,
 changed the rules to ban aerodynamic asymmetrical balls.
 Polara's producer sued the USGA and the association paid US$1.375 million in a 1985 out-of-court settlement.

The United States Patent and Trademark Office's patent database is a good source of past dimple designs.
 Most designs are based on Platonic solids such as icosahedron.

Golf balls are usually white, but are available in other high visibility colors,
 which helps with finding the ball when lost or when playing in low-light or frosty conditions.
As well as bearing the makers name or logo, balls are usually
printed with numbers or other symbols to help players identify their ball.

Selection

There are many types of golf balls on the market, and customers often face a difficult decision.
Golf balls are divided into two categories:
recreational and advanced balls. Recreational balls are oriented toward the ordinary golfer,
 who generally have low swing speeds (80 miles per hour or lower) and lose golf balls on the course easily.
These balls are made of two layers,
 with the cover firmer than the core.
Their low compression and side spin reduction characteristics
suit the lower swing speeds of average golfers quite well.
 Furthermore, they generally have lower prices than the advanced balls.

Advanced balls are made of multiple layers (three or more),
 with a soft cover and firm core.
They induce a greater amount of spin from lofted shots (wedges especially),
 as well as a sensation of softness in the hands in short-range shots. However,
 these balls require a much greater swing speed that only the physically strong players could
carry out to compress at impact.
If the compression of a golf ball does not match a golfer's swing speed,
either the lack of compression or over-compression will occur,
 resulting in loss of distance.
 There are also many brands and colors to choose from, with colored balls and better
brands generally being more expensive, making an individual's choice more difficult.

Marking and personalisation

A personalised golf ball

Golfers need to distinguish their ball from other players to ensure that they do not play
the wrong ball. This is often done by making a mark on the ball using a marker pen.
Special tools for marking balls with the players names or initials are also available. Alternatively,
balls can be printed with lettering, a pattern or a picture.
Companies and event organisers commonly have balls printed with their logo as a promotional tool.

Trick balls

A number of designs of novelty ball have been introduced over the years,
mainly as practical jokes for the amusement of fellow golfers, but also as "cheater"
balls that do not conform to the Rules of Golf. All of these are banned in sanctioned games,
but can be amusing in informal play:

• Breakaway balls are brittle and hollow, and shatter into many small pieces when hit.
• Exploding balls are similar, but employ a small explosive device that disintegrates the ball when hit.
•  Many courses have banned these as the charge can damage the turf, the player's club or 
• even cause injury, leading manufacturers to develop the breakaway.
• Stallers are far softer than a normal golf ball, allowing them 
• to be compressed far more easily and are given greater backspin when hit. 
• Both of these give the ball a huge amount of lift, producing shots that climb very high into 
• the air with very little distance traveled over the ground. In the right conditions,
•  such a ball may travel backwards along its flight path or even perform a loop-de-loop.
• Sponge balls are softer still; they are generally 
• used as indoor or backyard practice balls, 
• but some are deceptively similar in appearance to a normal ball. Such a ball will travel less than 
• a quarter of the distance of a normal golf ball.
• Wobblers have a center of mass that is not in the exact center of the ball 
• or is loose within the ball. When putted, the ball will move unpredictably off the intended line.
• Floaters are less dense than a regulation golf ball so when hit into a water hazard, they bob 
• on the surface when a normal ball would sink.
• Super-distance balls have deeper dimples and are heavier than allowed by regulation, 
• which allows them first to maintain momentum and second to maintain a thicker "envelope" 
• of still air around them which reduces turbulence and wind resistance. 
• Marketers of these balls generally advertise a 12-yard gain on most distance shots.
• Night golf balls Glow in the dark golf balls either luminous balls or inserted glow sticks.

Used and refurbished golf balls

golf , جولف , مدونة اخبار الفوركس , اختصار روابط , ترايدنت,

Used golf balls are golf balls that have been played,
most likely hit out of bounds or into a water hazard,
 then retrieved, cleaned up and resold. Used golf balls
come in different gradings, such as mint (AAAAA), near mint (AAAA)
 or practice (AA). They are sometimes referred to as "lakeballs".
Damaged golf balls with cuts or path marks are also known as
"hit-aways" and usually sold in bulk for practice play.

Cleaned recycled golf balls means "Cleaning only".
 The found golf ball goes through a wash process that allows the recovered golf balls
to soak in a cleaning solution.
The golf balls are then washed in a specially designed golf ball washer.
Some companies remove most or all the clear coat from the ball with a mechanical wet blasting process.
 This process allows them to get the golf ball as clean as possible before re-clear coating.
 The objective of the freshly applied clear coat is to provide a consistent and more durable recycled product.
Refinished golf balls are processed by stripping, painting and/or clear-coating.
The original paint and finish from the golf balls is removed using,
a mechanical wet blasting process,
the equipment utilized in this process is similar to equipment used in
the process of removing mould lines and prepping many new golf balls,
 before they are painted in the factory.
This leaves the original surface to be re-painted, printed and then re-clear coated.
 This process is utilized mostly for more expensive balls such as Pro V1, HX Tour, and Nike one etc.
 The same process is also used by some factories to correct misprints.
 Independent testing has shown that refinished
 golf balls have only minimal change in flight or roll characteristics,
 the average player would never feel the differences. Refinishing can not repair cuts,
 scrapes or path marks

Radio location

Golf balls with embedded radio transmitters to allow lost balls to be
 located were first introduced in 1973, only to be rapidly banned for use in competition.^[8][9]
 More recently RFID transponders have been used for this purpose.
This technology can be found in some computerized driving ranges.
 In this format, each ball used at the range has its own unique transponder code.
 When dispensed, the range registers each dispensed ball to the player,
 who then hits them towards targets in the range.
When the player hits a ball into a target, they receive distance and accuracy
 information calculated by the computer.

World records

Canadian long drive champion Jason Zuback broke the world ball speed record
on an episode of Sport Science with a golf ball speed of 328 km/h (204 mph).
 The previous record of 302 km/h (188 mph) was held by José Ramón Areitio, a Jai Alai player.

Golf club (equipment)

Golf club (equipment)

From Wikipedia, the free encyclopedia

Three golf clubs of different classes. From left to right are a driver, a putter, and an iron.

A golf club is used in the sport of golf to hit a golf ball. Each club is composed of 

a shaft with a lance (grip) and a clubhead. Woods are mainly used for long-distance fairway 

or tee shots; irons, the most versatile class, are used for a variety of shots; 

putters are used mainly on the green to roll the ball into the cup.

 A golf club is the tool used in the game of golf and from where the name came from, 

“kolbe” (German for club). Despite there being no definitive origin to the sport, 

Scotland is considered the “home of golf.” It has been played for over four centuries with Scotland having 

the official first club golf course, St.

 Andrews. In a standard set there are 14 golf clubs, consisting of irons, 

woods and a putter. Although there is no official limit to each club, golfers tend to have 3 to 4

 woods, 7 or 8 irons, a wedge and a putter.

An important variation in different clubs is loft, or the angle between the club's face and the vertical 

plane. It is loft that makes a golf ball leave the tee on an ascending trajectory, not the angle of swing;

 all swings contact the ball with a horizontal motion. The impact of the club compresses the ball,

 while grooves on the clubface give the ball backspin (which would appear as a clockwise spin

 on the ball when viewed from the standpoint of a right-swinging golfer, or as acounter-clockwise

 spin when viewed from the standpoint of a left-swinging golfer). Together,

 the compression and backspin create lift. The majority of woods and irons are labeled with 

a number; higher numbers indicate shorter shafts and higher lofts, which give the ball a higher and shorter trajectory.

History

A set used to play a round of golf, under the rules of golf, must have no more than 14 clubs. While the variation of clubs differs between golfers, a full set typically consists of a driver, two fairway woods (generally 3- and 5-woods), a set of irons from 3 to 9, a pitching wedge, a sand wedge, a putter, and one more club of the player's choice. Many players opt to avoid the long irons (that many find difficult to hit) and replace them with more forgiving clubs, like hybrids, although a small number of players choose to carry a 2-iron rather than a third wood. In 1744, the rules were officially documented and golf started to gain popularity. Many of the original golf clubs had wooden shafts and steel heads until this time period. Whether the game was being played in Scotland, Belgium, or any other country the golf clubs did not differ in the materials. However in the middle of the 18th century, it had switched to wood and only two golf clubs did not have wooden heads, the “niblick and the “cleek.” The golf club has changed so much through time, with the ability to be adequately fit to a player’s shape, size, age, or sex. In the beginning stages of golf, those who played would play with cut branches from trees and now have been revolutionized. There is no specific or set standardization as the club now can be varied in many ways. Before, the golfers only had wooden shafts, mostly wooden heads and/or heavy steel heads and thus led to ineffective playing. The golf balls were made of leather and feathers, known as featheries until the gutta-percha was introduced in 1848. The gutta-percha made the golf balls round and smooth making the accuracy difficult to control. Rubber was later included in the balls the players realized balls with dents or creases easily helped with the accuracy. The size and weight of the golf ball varied for a long time until it was decided on 1.62 inches and ounces. This was until 1932 when the USGA (United States Golf Association) in 1990 decided on 1.68 inches but left it at 1.62 ounces. These became the international rules as well and have not changed since.

Materials

The shafts of the Golf club woods were made of different types of wood before taken over by hickory. The varieties of woods include ash, greenheart, purpleheart, lancewood, lemonwood, orangewood, and blue-mahoo. In the middle of the 19th century the shafts were then being replaced by hickory wood. Despite this strong wood being the primary material, the long-nose club of the mid nineteenth century was still prone to breaking at the top of the backswing. The club heads were often made from thorn, apple, pear, dogwood, beech in the early times until persimmon became the main material. Golf clubs have been developed and the shafts are now made of steel, titanium, carbon fiber, or other types of metals. The shaft is a tapered steel tube or a series of stepped steel tubes in telescopic fashion. This has helped the accuracy of golfers. The grips of the clubs are made from leather or rubber.

Club Types

Woods

Main article: Wood (golf)

Woods are long-distance clubs, meant to drive the ball a great distance down the fairway towards the hole. They generally have a large head and a long shaft for maximum club speed. Historically woods were made from Persimmon wood although some manufacturers - notably Ping - developed laminated woods. In 1979, TaylorMade Golf introduced the first metal wood made of steel. Even more recently manufacturers have started using materials such as carbon fiber, titanium, or scandium. Even though most 'woods' are made from different metals, they are still called 'woods' to denote the general shape and their intended use on the golf course. Most woods made today have a graphite shaft and a titanium, composite, or steel head. Woods are the longest clubs and the most powerful of all the golf clubs. There are typically three to four woods in a set which are used off the tee box and, if on a long hole, possibly for the second or even third shot. The biggest wood, known as the driver, is often made of hollowed out titanium with feather light shafts. The length of the woods have been increasing in recent decades, and a typical driver with a graphite shaft is now 45.5 inches long. The woods may also have very large heads, up to 460cc in volume. It has a greater weight in the head and sole than in any other point in the club. This is also the same in irons. The shafts range from regular to extra-stiff depending upon each person’s preference.

Irons

Main article: Iron (golf)

Irons are golf clubs with a flat angled face and a shorter shaft than a wood, designed for shots approaching the green or from more difficult lies such as the rough, through or over trees, or the base of hills. Irons are used during the middle of each hole off the roughs, fairways or sand traps. There are long irons, medium irons, and short irons all with flat heads. They are called irons because they were made of metal. As with Woods, there are special types. Wedges, invented by Gene Sarazan are a special type of iron that took the place of the “niblick.” They are heavy and shorter than other irons, with a less flat face to loft the ball higher. with woods, "irons" get their name because they were originally made from forged iron. High-loft irons are called wedges. The higher the number gets on the scale, the lower amount of angle difference from 90 degrees. Irons are often hybrid, cavity-back or muscle-back. A hybrid is any iron that features a head very similar to a fairway wood; hollow steel or titanium with a shallow, slightly convex face. A hybrid head is usually marginally shallower and does not extend backwards from the face as far as a comparable fairway wood. A Cavity-back iron is any iron in which a small to large amount of the metal across the back of the head is removed, allowing that weight to be re-positioned on the perimeter of the head, farther away from the head's center of gravity. A muscle-back iron is any iron in which there is no cavity on the back of the head, i.e., the weight is more evenly distributed across the back of the clubhead.

Wedges are irons with a higher loft than a 9 iron, which is typically lofted at about 42 degrees. Wedges are used for a variety of short-distance, high-altitude, high-accuracy shots such as hitting the ball onto the green ("approach" shots), placing the ball accurately on the fairway for a better shot at the green ("lay-up" shots), or hitting the ball out of hazards or rough onto the green (chipping). There are usually six types of wedges with lofts ranging from 45° to 64°: pitching wedge (PW 48°), gap wedge (GW 52°), sand wedge (SW 56°), lob wedge (LW 60°), and ultra lob wedge (LW 64°).[1] The pitching wedge is sometimes called or labeled as a 10 iron, and the gap wedge is sometimes called an approach wedge or Utility Wedge and labeled with AW or UW respectively.

Hybrids

Main article: Hybrid (golf)

Hybrids are a cross between a wood and an iron, giving these clubs the wood's long distance with the iron's familiar swing. These clubs generally are used instead of high-numbered woods and/or low-numbered irons, though some manufacturers produce entire sets of hybrids or "iron replacements" that incorporate hybrid design to add distance and forgiveness to a player's entire set of irons from 1 to pitching wedge. Most hybrids take the place of an iron, but the hybrid is easier to hit than its respective iron. These clubs are often referred to as "Rescues" because the TaylorMade Rescue was one of the first clubs to utilize this design, as well as the use of the clubs to get one out of a tricky position (to be in fact rescued by the club).

Putters

Main article: Putter

Putters are a special class of clubs with a loft not exceeding ten degrees (except chippers), designed primarily to roll the ball along the grass, generally from a point on the putting green towards the cup. Contrary to popular belief, putters do have a loft (often 5 degrees from truly perpendicular at impact) that helps to lift the ball from any indentation it has made. Newer putters also include grooves on the face to promote roll rather than a skid off the impact. This increases rolling distance and reduces bouncing over the turf. Also present in some golfers' bags is the "chipper" which is designed for low-speed swings to lift the ball a short distance about 25 yards/23 meters, onto the green. The club can be used in place of the pitching wedge with an abbreviated swing to accomplish the same end. This club is used only on the greens and is the finishing club for each hole. These clubs were originally made of wood but have also been developed to metals as well. These are the shortest clubs of the set.

Chippers

Another variation of the putter, called the chipper, has a similar look, feel and general construction as a "normal" putter, but with a much higher loft, often 30-45 degrees. It is used to lift the ball over or out of the rough or fringe and onto the green with a motion similar to a putt. It can also be used for "lagging" (a putt made on the green from long distance for the sole purpose of setting up the ball for an easier second putt). A putter used for this purpose would require a harder stroke and the rough or fringe could affect accuracy. A high-angle wedge could have similar accuracy issues and could also damage the turf on such a shot if made carelessly. However, its use is generally limited; it is best-suited for short-distance play from close-cut grass on a terrain level similar to that of the green, and as such most skilled golfers choose to use a low-bounce, wide-soled wedge with a putting motion to accomplish a similar effect and save the space the club would take for a more versatile club.

Shaft

Main article: Shaft (golf)

Loft and lie of a golf club.

The shaft is a tapered tube made of metal (usually steel) or carbon fiber composite (referred to as graphite). The shaft is roughly 0.5 inches (13 mm) in diameter near the grip and from 34 to 48 inches (86 to 122 cm) in length. Shafts weigh from 45 to 150 grams (1.6 to 5.3 oz), depending on the material and length.[citation needed]

Shafts are quantified in a number of different ways. The most common is the shaft flex. Simply, the shaft flex is the amount that the shaft will bend when placed under a load. A stiffer shaft will not flex as much, which requires more power to flex and "whip" through the ball properly (which results in higher club speed at impact for more distance), while a more flexible shaft will whip with less power required for better distance on slower swings, but may torque and over-flex if swung with too much power causing the head not to be square at impact, resulting in lower accuracy. Most shaft makers offer a variety of flexes. The most common are: L (Lady), A (Soft Regular, Intermediate or Senior), R (Regular), S (Stiff), and X (Tour Stiff, Extra Stiff or Strong). A regular flex shaft is generally appropriate for those with an average head speed (80–94 mph (130–151 km/h)), while an A-Flex (or senior shaft) is for players with a slower swing speed (70–79 mph (110–127 km/h)), and the stiffer shafts, such as S-Flex and X-Flex (Stiff and Extra-Stiff shafts) are reserved only for those players with an above average swinging speed, usually above 100 mph (160 km/h). Some companies also offer a "stiff-regular" or "firm" flex for players whose club speed falls in the upper range of a Regular shaft (90–100 mph (140–160 km/h)), allowing golfers and clubmakers to fine-tune the flex for a stronger amateur-level player.[citation needed]

On off-center hits, the clubhead twists as a result of a torque, reducing accuracy as the face of the club is not square to the player's stance at impact. In recent years, many manufacturers have produced and marketed many low-torque shafts aimed at reducing the twisting of the clubhead at impact; however, these tend to be stiffer along their length as well. Most recently, many brands have introduced stiff-tip shafts. These shafts offer the same flex throughout most of the Shaft, in order to attain the "whip" required to propel the ball properly, but also include a stiffer tip, which cuts back drastically on the lateral torque acting on the head.[citation needed]

Widely overlooked as a part of the club, the shaft is considered by many to be the engine of the modern clubhead. Shafts range in price from a mere US$20 to over US$1200. Current graphite shafts weigh considerably less than their steel counterparts (sometimes weighing less than 50 grams (1.8 oz) for a driver shaft), allowing for lighter clubs that can be swung at greater speed. Within the last ten years[when?], performance shafts have been integrated into the clubmaking process. Performance shafts are designed to address specific criteria, such as to launch the ball higher or lower or to adjust for the timing of a player's swing to load and unload the shaft at the correct moments of the swing for maximum power. Whereas in the past each club could come with only one shaft, today's clubheads can be fitted with dozens of different shafts, creating the potential for a much better fit for the average golfer.[citation needed]

Grip

In modern times, the grip has undergone a number of iterations. The large variety of models makes it far easier than in the past for a discriminating golfer to find a comfortable model.

Grip rules

According to the rules of golf, all club grips, with the exception of the putter, must have a circular cross-section. The putter may have any cross section that is symmetrical along the length of the grip through at least one plane. Grips may taper from thick to thin along their length (and virtually all do), but they are not allowed to have any waisting (a thinner section of the grip surrounded by thicker sections above and below it) or bulges (thicker sections of the grip surrounded by thinner sections). Minor variations in surface texture (such as the natural variation of a "wrap"-style grip) are not counted unless significant.

Regripping

Advances in materials have resulted in more durable, longer-lasting soft grips, but nevertheless grips do eventually dry out, harden, or are otherwise damaged and must be replaced. Replacement grips sold as do-it-yourself kits are generally inexpensive and of high quality, although custom grips that are larger, softer, or textured differently from the everyday "wrap"-style grip are generally bought and installed by a clubsmith.[citation needed]

Regripping used to require toxic, flammable solvents to soften and activate the adhesive, and a vise to hold the club steady while the grip was forced on. The newest replacement kits, however, use double-sided tape with a water-activated adhesive that is slippery when first activated, allowing easier installation. Once the adhesive cures, it creates a very strong bond between grip and shaft and the grip is usually impossible to remove without cutting it off. Note that the grip is sometimes lubed for easier removal.

Hosel

The hosel is the portion of the clubhead to which the shaft attaches. Though largely ignored by players, hosel design is integral to the balance, feel and power of a club. Modern hosels are designed to place as little mass as possible over the top of the striking face of the club, which lowers the center of gravity of the club for better distance.

Clubhead

Each head has one face which contacts the ball during the stroke. Putters may have two striking faces, as long as they are identical and symmetrical. Some chippers have two faces, but are not legal. Page 135 of the 2009 USGA rules of golf states:[2]

"The clubhead must have only one striking face, except that a putter may have two such faces if their characteristics are the same, and they are opposite each other."[2]

Page 127 of the USGA rules of golf states:[3]

"A putter is a club with a loft not exceeding ten degrees designed primarily for use on the putting green."[3]

Therefore, any double sided club with a loft greater than 10 degrees is not legal.[2][3]

Ferrule

The decorative trim ring, usually black (It may have additional trim colors), that is found directly on top of the hosel on many woods and irons.

Regulations

The ruling authorities of golf, the Royal and Ancient Golf Club of St Andrews (R&A) and the United States Golf Association (USGA), reserve the right to define what shapes and physical characteristics of clubs are permissible in tournament play. Many recently developed woods have a marked "trampoline effect" (a large deformation of the face upon impact followed by a quick restoration to original dimensions, acting like a slingshot), resulting in very high ball speeds and great lengths of tee shots. As of 1 January 2008, the USGA and R&A have settled on a regulation that limits the acceptable "trampoline effect" to a coefficient of restitution (COR) – a measurement of the efficiency of the transfer of energy from the club head to the ball – of .830.[4]

Other large scale USGA rulings involve a 1990 lawsuit, and subsequent settlement, against Karsten Manufacturing, makers of the PING brand, for their use of square, or U-grooves in their immensely popular Ping Eye2 irons. The USGA argued that players who used the Eye2 had an unfair advantage in imparting spin on the ball, which helps to stop the ball on the putting greens. The USGA utilizedJohn L. Saksun, founder of Canadian golf company Accuform Golf, as a consultant to set up methods of measuring the unique grooves and determining PING's compliance with the rulings.[5] Saksun, by proposing a cost-effective solution to help PING change the design of subsequent Eye2s, saved PING hundreds of millions. PING subsequently withdrew their US$100 million lawsuit against the USGA. Ping’s older clubs were "grandfathered in" and allowed to remain in play as part of the settlement.[6] Today, square grooves are considered perfectly legal under the Rules of Golf. However, the USGA has determined that square grooves are illegal in elite-level competition.[7] According to the USGA, as January 1, 2010, professional golfers on one of the top tours, or those attempting to qualify for one of the three Open Championships, will need to be utilizing new conforming wedges (those without square grooves).[8][9] Moreover, those who plan to qualify for any other USGA championship will need new conforming wedges by 2014. In addition, this regulation might include amateur events as well. Casual golfers may use square groove wedges (and clubs) until at least 2024.

References

^ http://www.lindgolf.com/buying-guide/wedges

^ a b c USGA rules of golf, p 135.

^ a b c USGA rules of golf, p 127.

^ Stachura, Mike (2002-10). About-face: the USGA's final edict on COR should end the confusion over which drivers conform and which do not. Golf Digest, October 2002. Retrieved fromhttp://findarticles.com/p/articles/mi_m0HFI/is_10_53/ai_93487351.

^ Weeks, Bob (2007-02-16). Grooves: the new rules battleground. SCOREGolf: The Voice of Canadian Golf, 16 February 2007. Retrieved from http://scoregolf.com/blog/bob-weeks/2007/February/Grooves-the-new-rules-battleground.cfm.

^ Diaz, Jaime (January 29, 1990). "Accord Is Reached On U-Groove Irons". The New York Times. Retrieved 2009-11-22.

^ Potter, Jerry (March 12, 2007). "Club grooves limitation sought". USA Today. Retrieved 2009-11-22.

^ a b http://www.mygolfspy.com/usga-2010-groove-rule/

^ http://www.golf.com/golf/tours_news/article/0,28136,1596949,00.html

Bade, Edwin. The Mechanics of Sport. A.G. Elliot, New York, 1952. Gibson, Kevin H. The Encyclopedia of Golf. A.S. Barnes, New York, 1958. Bruce, Ben and Evelyn Davies. Beginning Golf. Wadsworth Publishing, California, 1962. Cheatum, Billy Ann. Golf. W.B. 

Saunders Company, Philadelphia, 1969. Cochran A.J. Science and Golf II: Procedures of World Scientific Congress of Golf. M.R. Farally, London, 1994. Cook, Kevin. Driven: Teen phenoms, Mad Parents, Swing Science and the Future of Golf. Gotham Books, New York, 2008. Concannon, Dale. The Original Rules of Golf. Bodleian Library, Oxford, 2009. Evans, Webster. Encyclopaedia of Golf. St. Martins Press, New York, 1971. Ford, Doug. Getting Started in Golf. Sterling Publishers, New York, 1964.

Golf course

A golf course consists of a series of holes, each consisting of a teeing ground, fairway, rough and other hazards, and a green with a flagstick (pin) and cup, all designed for the game of golf. A standard round of golf consists of playing 18 holes, thus most golf courses have this number of holes. Some, however, only have nine holes and the course is played twice per round, while others have 27 or 36 and choose two groups of nine holes at a time for novelty and maintenance reasons. Additionally, par-3 courses also exist, consisting of nine or 18 holes, all of which are a Par 3. Many older golf courses, often coastal, are golf links, of a different style to others. For non-municipal courses, there is usually a golf club based at each course, and may include a pro shop.

Teeing area

Tee for the first hole at The Links at Spanish Bay

The first section of every hole consists of what is known as the teeing ground, or tee-box. There is usually more than one available box for a player to place their ball, each one a different distance from the hole. They are generally as level as feasible, and most are slightly raised from the surrounding fairway. The most common tee areas, in increasing order of length from the hole, are the ladies' tee, the men's tee, and the championship tee. Other common tee-boxes include the junior tee, closer to the hole than the ladies' tee, and the senior tee, generally between the ladies' tee and the men's tee. In tournaments, golfers generally tee off from the box one level further from the "normal" box for their class (men use the championship tee, ladies use the senior or men's tee, and juniors use the ladies' tee).

Each tee box has two markers showing the bounds of the legal tee area. The teeing area spans the distance between the markers, and extends from two-club lengths behind the markers up to the markers themselves. A golfer may play the ball from outside the teeing area, but the ball itself must be shot from within the area.^[1] A golfer may place his ball directly on the teeing ground (called hitting it "off the deck"), a manufactured support known as a tee, or any natural substance such as sand placed on the teeing surface.

Fairway and rough

Typical doglegs. On the left side: "dogleg left", on the right side: "double dogleg"

After the first shot from the tee (teeing off), the player hits the ball from where it came to rest toward the green. The area between the tee box and the putting green where the grass is cut even and short is called the fairway and is generally the most advantageous area from which to hit. The area between the fairway and the out-of-bounds markers and also between the fairway and green is the rough, the grass of which is cut higher than that of the fairway and is generally a disadvantageous area from which to hit. On par three holes the player is expected to be able to drive the ball to the green on the first shot from the tee box. On holes longer than par threes players are expected to require at least one extra shot made from the fairway or rough.

While many holes are designed with a direct line-of-sight from the tee-off point to the green, some holes may bend either to the left or to the right. This is called a "dogleg", in reference to a dog's knee. The hole is called a "dogleg left" if the hole angles leftwards, and a "dogleg right" if the hole angles rightwards. Sometimes, a hole's direction can bend twice, and is called a "double dogleg".

Just as there are good quality grasses for putting greens, there are good quality grasses for the fairway and rough. The quality of grass influences the roll of the ball as well as the ability of the player to 'take a divot' (effectively, the ability to hit the ball into the turf and compress it). The fairways on prestigious tours, like the PGA Tour, are cut low, making it harder for players to compress the ball. Mow heights influence the play of the course; for example, the grass heights at U.S Open events are alternated in order to make the golf course difficult. One example of this is the infamous roughs at U.S Opens, which are often 3 to 5 inches tall depending on how close to the fairway or green the said height will be. This makes it harder for a player to recover after a bad shot.

Some variants of grass used for fairways and roughs are bent grass, Tifway 419 Bermuda grass,^[2] rye grass, Kentucky bluegrass, and Zoysiagrass. As in putting green grass types, not every grass type works for every climate type.

Hazards

Main article: Hazard (golf)

Water hazard, sand trap, and dense vegetation on the 13th hole at Ridgefield Golf Course, CT

Many holes include hazards, which may be of three types: (1) water hazards such as lakes and rivers; (2) man-made hazards such as bunkers; and (3) natural hazards such as dense vegetation. Special rules apply to playing balls that fall in a hazard. For example, a player may not touch the ground with his club before playing a ball, not even for a practice swing. A ball in any hazard may be played as it lies without penalty. If it cannot be played from the hazard, the ball may be hit from another location, generally with a penalty of one stroke. The Rules of Golf govern exactly from where the ball may be played outside a hazard. Bunkers (or sand traps) are shallow pits filled with sand and generally incorporating a raised lip or barrier, from which the ball is more difficult to play than from grass. As in any hazard, a ball in a sand trap must be played without previously touching the sand with the club.

Putting green

The 18th green at Pebble Beach Golf Links

To putt is to play a stroke on the defined putting surface. Usually, this stroke is played on the green with a putter where the ball does not leave the ground. Once on the green, the ball is putted (struck with the eponymous flat-faced club to roll it along the ground) toward the hole until the ball falls into the cup.

The grass of the putting green (more commonly just green) is cut very short so that a ball can roll long distances. The most common types of greens for cold winter, but warmer (not extremely warm i.e. Southern United States) are bent grass greens. These are considered the best greens because of their ability to be cut to extremely low heights, and their ability to be grown from seed. Bent grass does not have grain, which makes it superior as a putting surface; however, bent grass often gets infested with poa annua, which is a costly and time consuming weed. Augusta National is one of many golf courses to use these types of greens; the original design of Augusta National did not have bent grass greens, however, in the 1980s, the controversial decision was made that changed the greens to bent grass, from Bermuda.

This has affected the speed and playing of Augusta National. Another type of grass common for greens is TifDwarf Hybrid Bermuda (other variants exist, but TifDwarf is one of the most common, or simply Bermuda grass. This type of grass is more common in places that do not have cold winters, yet have very warm summers (such as the southern portion of the United States, and the southwestern states). A green is generally established from sod which has had the soil washed off of it as to avoid soil compatibility problems and then laid tightly over the green, rolled and topdressed with fine sand. Another common and more economical approach for establishing a putting green is hybrid Bermuda spriggs, which are the stolon of the grass which are raked out at the sod farm and laid out on the green to establish. The best greens are always established vegetatively and never from seed.

A downside to Bermuda greens is the cost of maintenance, and the existence of grain (The growth direction of the blades of grass affects the ball's roll and is called the grain of the green). The slope or break of the green also affects the roll of the ball. The cup is always found within the green and must have a diameter of 108 millimeters (4.25 in) and a depth of at least 10 centimeters (3.94 in). Its position on the green is not fixed and should be changed daily by a greenskeeper in order to prevent excessive wear and damage to the turf. The cup usually has a flag on a pole positioned in it so that it may be seen from a distance, but not necessarily from the tee; this flag-and-pole combination is called the pin or less commonly the flagstick.

Putting greens are not all of the same quality. Generally, the finest-quality greens are well kept so that a ball will smoothly roll over the closely-mowed grass. Excess water can be removed from a putting green using a machine called a water hog. Golfers describe a green as fast if a light stroke to the ball makes it roll a long distance; conversely, a slow green is one where a stronger stroke is required to roll the ball the required distance. The exact speed of a green can be found with a stimp meter. By collecting sample measurements, golf courses can be compared in terms of average green speed. It is, however, illegal by the Rules of Golf to test the speed of a green while playing by rolling a ball on it, feeling or rubbing the green.

Par

Mark Bostic Golf Course

Most courses have only par three, four, and five holes, though some courses include par six holes. Typical distances for the various holes from standard tees are as follows.

Men

• Par 3 – 250 yards (230 m) and below
• Par 4 – 251 to 450 yards (410 m)
• Par 5 – 451 to 690 yards (630 m)
• Par 6 – 691 yards (632 m) or more

Women

• Par 3 – 210 yards (190 m) and below
• Par 4 – 211 to 400 yards (370 m)
• Par 5 – 401 to 575 yards (526 m)
• Par 6 – 575 yards (526 m) or more

Harder or easier courses may have longer or shorter distances, respectively. Terrain can also be a factor, where a long downhill hole might be rated a par four, but a shorter uphill or treacherous hole might be rated a par five. Professional tournament players will often encounter longer Par 3 holes (up to 290 yards) and longer Par 4 holes (up to 520 yards).

Other areas

Some areas of the course are designated as ground under repair ("G.U.R."), where greenskeepers are making repairs or where the course is damaged. A ball coming to rest in this spot may be lifted, then played from outside the G.U.R. without penalty. Certain man-made objects on the course are defined as obstructions (i.e. distance posts, gardens, etc.), and specific rules determine how a golfer may proceed when their play is impeded by these.

Driving range

Main article: Driving range

Practice range with 43 tees (20 covered)

Often, there is a practice range or driving range, usually with practice greens, bunkers, and driving areas. Markers showing distances are usually included on a practice range to benefit the golfer. There may even be a practice course (often shorter and easier to play than full-scale golf courses), where golfers practice to measure how far they can hit with a specific club or to improve their swing technique.

Design

A specialty of landscape design or landscape architecture, golf course architecture is its own field of study. Some golf course architects become celebrities in their own right. The field is represented by the American Society of Golf Course Architects, the European Institute of Golf Course Architects and the Society of Australian Golf Course Architects.

Golf match at Columbia Country Club, Washington, D.C. area 1910-20.

While golf courses often follow the original landscape, some modification is unavoidable. This is increasingly the case as new courses are more likely to be sited on less optimal land. Bunkers and sand traps are almost always artificial, although other hazards may be natural.

The layout of fairways follows certain traditional principles, such as the number of holes (nine and 18 being most common), their par and number of chosen par types per course. It is also preferable to arrange greens to be close to the tee box of the next playable hole, to minimize travel distance while playing. Combined with the need to package all the fairways in a compact square or rectangular land plot, they tend to form an oppositional tiling pattern. In complex areas, sometimes two holes share a single tee box. It is also common for separate tee-off points to be positioned for men, women, and amateurs, each one respectively lying closer to the green.

A successful design is as visually pleasing as it is playable. With golf being an outdoor form of recreation, the strong designer is an adept student of natural landscaping, understanding the aesthetic cohesion of vegetation, water bodies, paths, grasses, stonework and woodwork, among other things.

A special design of golf course is the "executive" golf course (also known as a "par-3" course). This course differs from standard courses in that the majority of holes are Par 3 holes, with one or two Par 4 holes added and sometimes (though rare) a Par 5 hole. The executive course is designed for beginner or older golfers and those who lack the time to play a round on a standard course.

Environmental impact

Environmental concerns over the use of land for golf courses have grown over the past fifty years. Specific issues include the amount of water and chemical pesticides and fertilizers used for maintenance, as well as the destruction of wetlands and other environmentally important areas during construction. The UN estimates that golf courses use about 2.5 billion gallons/9.5 billion liters of water daily. Many golf courses in the world are irrigated with non-potable water and/or rainwater. In 1988, the US Environmental Protection Agency prohibited the use of Diazinon on golf courses and sod farms because of negative impact on bird species.

These, along with health and cost concerns, have led to research into more environmentally sound practices and turf grasses. The golf course superintendent is often trained in the uses of these practices and grasses. This has led to significant reduction in the amount of chemicals and water used on courses. The turf on golf courses is an excellent filter for water and has been used in communities to cleanse grey water, such as incorporation of bioswales.

Environmentalists and other activists continue to oppose golf courses for environmental reasons, as they occasionally impede corridors for migrating animals and sanctuaries for birds and other wildlife, though courses frequently become havens for native and non-native creatures.

A result of modern equipment is that today's players can hit the ball much farther than previously. As a result, out of a concern for safety, golf course architects have had to lengthen and widen golf courses. This has led to a ten percent increase in the acreage required to build them. At the same time, water restrictions placed by communities have forced courses to limit the amount of maintained turf grass. While most modern 18-hole golf courses occupy as much as 60 hectares (150 acres) of land, the average course has 30 Ha (75 acres) of maintained turf. (Sources include the National Golf Foundation and the Golf Course Superintendents Association of America GCSAA.)

Deer on a golf course.

Golf courses can be built on sandy areas along coasts, abandoned farms, strip mines and quarries, deserts and forests. Many Western countries have instituted environmental restrictions on where and how courses can be built.^[3][4]

In some parts of the world, attempts to build courses and resorts have led to protests, vandalism and violence. Golf is perceived by some as elitist, and thus golf courses become a target for popular opposition. Resisting golf tourism and golf's expansion has become an objective of some land-reform movements, especially in the Philippines and Indonesia.

In the Bahamas, opposition to golf developments has become a national issue. Residents of Great Guana Cay and Bimini, for example, are engaged in legal and political opposition to golf developments on their islands, for fear the golf courses will destroy the nutrient-poor balance on which their coral reef and mangrove systems depend.

In Saudi Arabia and elsewhere in arid regions, golf courses have been constructed on nothing more than oil-covered sand. Players may use a roller on the "greens" to smooth the intended path before putting. In Coober Pedy, Australia, there is a golf course that consists of nine holes dug into mounds of sand, diesel and oil, with no grass anywhere on the course. Players carry a small piece of astroturf from which they tee the ball. In New Zealand it is not uncommon for rural courses to have greens fenced off and sheep graze the fairways. At the 125-year-old Royal Colombo Golf Club in Sri Lanka steam trains, from the Kelani Valley railway, run through the course at the 6th hole.

Extreme golf is played on environmentally sustainable alternatives to traditional courses. A cross between hiking and golf, the course layout exposes players to a wide range of natural obstacles and challenging terrains.

Based on the growing popularity of the U.X. Open Alternative Golf Tournament the extreme golf course features un-mowed meadows and forest instead of fairways, with "goals" scored on temporary greens (a circle 6 metres (20 ft) in diameter).^[5]