A wood (also called a driver) is a type of club used in the sport of golf. Woods are used to hit the ball farther (greater distances) than any other type of golf club.

Woods are so called because, traditionally, they had a club head that was made from hardwood, generally persimmon^[1] but modern clubs have heads made from metal, for example titanium, or composite materials, such as carbon fiber. Some golf enthusiasts refer to these as "metals" or "metal woods" but this change in terminology is not strictly necessary, because while the material has changed, the style and intended use has not. The change to stronger materials has allowed the design of the modern woods to incorporate significantly larger heads than in the past. Because of the increase in club head size, in 2004 the USGA created a new stipulation for the size of the club head. The legal maximum (by the rules of golf) of a wood is 460 cc (28.1 cu in)^[2].

Woods are numbered in ascending order with the driver, or 1-wood, which is designed to hit the ball the greatest distance, having the longest length and lowest loft, typically between 7 and 13 degrees. However there is no industry standard and some overlap occurs. With the typical loft of a 2-wood being 12-13° a 1-wood and 2-wood could have the same loft. Other differences in club design, such as head size, face roll, weight distribution, lie angle, or club length, could also differentiate a 12° 1-wood intended for tee shots and a 12° 2-wood intended for fairway shots. Most club manufacturers’ matched sets include 1-3-5 numbered woods. Even numbers are less common with modern clubs. The number of the club is mainly a reference for the player to easily identify the clubs. Other identifiers have been utilized such as strong and plus to differentiate various lofts within a line of clubs.

Woods generally fall into two classes, drivers and fairway woods, with a traditional set of 14 clubs comprising a driver, two fairway woods (3 and 5), ten irons and a putter^[2]. Many modern sets tend to include hybrid clubs, which combine some of the characteristics of a wood and an iron, to replace the 5 wood and longer (3 and 4) irons.

Drivers[link]

The longest and lowest-lofted wood is the driver, or 1 wood, and has the longest range of any club in a golfer's bag. It is designed to be hit off the tee for the first shot of long-yardage holes. The driver can also be hit from the turf, although modern deep-faced drivers require a high level of skill and a certain amount of luck regarding the "lie" of the ball to execute such a shot correctly. Some 2-woods also have a similar deep-face oversized design, used for tee shots requiring less distance than the player's average drive or for players with slower swing speeds to achieve the optimum distance using their slower swing tempo. The driver is generally the largest, longest, and often the lightest of the golf clubs in the player's bag. With the increased design technology in modern clubs, the cost of drivers has dramatically increased. While "entry-level" drivers are available as cheaply as $20, these are usually marketed for junior players; clubs marketed to amateur adult players by major brands such as TaylorMade, Callaway and Golfsmith now cost between $125-$450 at retail, and a custom-fit club built on a "boutique" clubhead may cost up to $2200.

Fairway woods[link]

Higher-number woods are generally known as fairway woods and, as their name suggests, are designed for shots from off the turf of the fairway that still require long distance, such as the second shot of a par-5 or a long par-4 hole. They have two important features: a higher loft to lift the ball out of the turf and over low obstacles like hills, and a shallower face height which allows a player to hit a ball from the ground using the exact center of the club, providing greater distance for such shots. These two design features enable players to hit fairway woods off the ground with ease. Fairway woods are also useful off the tee depending on the hole; players may for instance wish to play their tee shot short (known as "laying up") due to a dogleg or a hazard in range of their driver, and will opt instead for their 3-wood. This club is made with a slightly shorter and stiffer shaft and more loft than a driver or 2-wood, and is used through the green for long high shots.

Usage[link]

The most common set of clubs has three woods: 1-, 3- and 5- woods. However, there are many variations depending on the player and the course, and fairway woods of any number from 2 to 15 are produced and preferred by various players. The 7- and 9-wood are common among ladies, male seniors and children.

Design[link]

The head of a wood is roughly spherical in shape with a slightly bulging clubface and a generally flattened sole that slides over the ground without digging in during the swing. Traditional "wood" clubheads were made of wood, hence the name; beech wood or ash were common prior to the twentieth century, and later persimmon or maple became preferable. Modern club heads are usually hollow steel, titanium or composite materials, and are sometimes called "metalwoods" or more recently "fairway metals". Pinseeker Golf Corp. innovated the first stainless steel metalwood called the Bombshell in 1976. The design was somewhat untraditional and did not have the promotional success needed for profitable long term marketing - it was discontinued 3 years later. In 1979 Taylor Made produced a traditionally shaped stainless steel wood head called "Pittsburgh Persimmon" which achieved market acceptance by the mid-1980s. Oversized heads made from aluminum appeared in the mid 1980's but were slow to catch on since their introduction was via independent component manufacturers and not the larger endorsement based club manufacturers. Very large size drivers (300-500cc) arrived with titanium metallurgy which meant reasonable 'headweights' could be achieved with very large thin shelled but strong structures. By the mid 2000's, titanium heads could be made to 1000 cc (Golfsmith Inc made 1,000 cc (61.0 cu in) in the mid 2000's). Around this time the USGA decided to limit the size of driver heads to 460 cc (28.1 cu in) since the rule requiring heads to be of a traditional shape was being unduly stretched. However, during this period the club-making business needed some financial help, so the USGA relaxed the "traditional shape" rule while enforcing the new 460cc limit, and new head shapes appeared, such as "torpedo" and square/rectangular shapes, to attract the buying public to potentially game improving designs particularly regarding better mishit outcomes.

The typical loft for woods ranges from 7.5 to 31 degrees. Driver lofts generally centre around 10.5 degrees but the desired loft is very dependent upon the player's swingspeed (low swing speeds need higher lofts); men's lofts vary between 9 and 11 degrees while women's drivers are between 10 and 13 degrees, and seniors' lofts trend toward the upper range by gender. The average 3-wood has a 13-16 degree loft and the average 5-wood has an 18-19 degree loft. Higher lofts than that overlap with irons in distance, but many players prefer high-number woods to low-number irons wherever they can be used as the wood is easier to hit than a "long iron". The loft of any given club number varies between manufacturers, model lines, and the target player.

The shaft length in woods varies from about 40–48 inches (101.6–121.9 cm), with the current standard length for the driver being 45 in (114.3 cm), formerly 43.5 in (110.5 cm). Graphite shafts are usually preferred for woods due to their light weight, which enables users to generate higher clubhead speeds and thus greater distance. The maximum legal length of a shaft by USGA and R&A rules is 48 in (121.9 cm)^[2], though some woods used in long drive contests have been made with shaft lengths up to 50 in (127.0 cm) long.

Construction[link]

Shaft[link]

The shaft is the true engine of the wood. Widely overlooked, the proper shaft increases distance and accuracy, while a poor shaft can lead to inconsistent shots, slices, and reduced distance.

The oldest shafts for all golf clubs were made of Hickory wood. The shaft was whippy and light, but inconsistent in flex from club to club and quite fragile. Beginning in the 1920s, steel shafts started making an appearance, though the USGA and R&A did not allow their use in sanctioned tournaments until 1929^[1]. These shafts traded the lightness and flex of the wood shaft for vastly increased durability and consistency, and were the only type of shaft in general use on any club until the early 1990s. The modern "graphite" shaft (technically a carbon-fiber composite material) currently in use today combines advantages of the two older types of shafts; it is lighter and more flexible than either steel or Hickory, while having similar durability as steel, at the cost of slightly reduced shot consistency due to increased torque (though this has vastly improved on recent generations of shafts). Graphite shafts gained widespread popularity in the mid-1990s; although the carbon-fiber composite technology had been available since the early 1970s, it was very expensive to produce and nearly impossible to mass-market^[1]. Advances in producing, forming and curing composite materials have made carbon fiber much cheaper, and now virtually all new woods, regardless of price, have graphite shafts.

Shaft flex has a very pronounced effect on the power and accuracy of a wood. Every wood is somewhere in between the two extremes of flex, from the extra whippy, to the extra stiff. Whippy shafts are used by those who have low swing speeds and stiff by those who have faster swing speeds. The flex of a shaft allows it to store energy from a player's downswing, and release it as the head makes contact for increased club speed at impact. A shaft that is too stiff cannot be flexed by the golfer during their downswing, which reduces club speed at impact. A shaft that is too whippy will retain some of its stored flex at contact, wasting energy.

Shaft torque is also a concern. Flex and torque are generally related; the more a club can flex, the more it can also twist around its axis (though this is not always the case). A shaft that can torque easily is less forgiving of off-center shots as it will allow the head to twist, causing pulls and pushes. Low-torque shafts resist twisting for more forgiving behavior, but tend to be stiffer and require more power for proper distance. The latest generation of driver shafts combine a flexible shaft with a stiff tip, giving the golfer the required flex to "whip" into the ball while reducing clubhead twisting.

Head[link]

Wooden heads predominated until the late 1980s. They had evolved to include a metal sole and a metal or plastic faceplate. These wooden headed clubs were dense and heavy, and were generally much smaller than today's clubheads. Their smaller surface area also made consistent contact more difficult, as the sweet spot of these clubs was considerably smaller than today's models.

Gary Adams, founder of TaylorMade Golf, is considered the father of the modern metal wood. Adams began to market his club in the late 1970s, but it was nearly a decade until metal woods became more popular with most golfers. Callaway Golf is also largely responsible for the current design of metal woods; the original Big Bertha driver introduced players to the "oversize" driver with a larger and deeper clubhead (at the time it was 190cc in volume), giving maximum club face and a deeper center of gravity. Callaway Golf continued to expand the size of the clubhead to increase these effects, resulting in the Bigger Bertha, the Great Big Bertha, and others in the line. The current incarnation of the Big Bertha driver is 460cc, which is the maximum allowable clubhead volume according to USGA rules^[2], though larger clubheads exist for long-drive contests and informal games.

Today, many metal wood clubfaces (and most driver clubfaces) are constructed out of titanium. Titanium has a higher strength to weight ratio than steel and has better corrosion resistance, so it is an ideal metal for golf club construction. Manufacturers can also make clubheads with greater volume, which increases the hitting area, and thinner faces, which reduces the weight.

Hosel[link]

Traditional woods had a very thick hosel, often wrapped with thin cord, which provided a very secure joint between shaft and head at the cost of a higher center of gravity. Modern metalwoods have largely done away with the hosel altogether, instead anchoring the shaft within the clubhead. This allows as much mass as possible to be contained in the clubhead, lowering the center of gravity.

References[link]

Wood surface, showing several features

Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers (which are strong in tension) embedded in a matrix of lignin which resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees,^[1] or it is defined more broadly to include the same type of tissue elsewhere such as in tree roots or in other plants such as shrubs.^{[citation needed]} In a living tree it performs a support function, enabling woody plants to grow large or to stand up for themselves. It also mediates the transfer of water and nutrients to the leaves and other growing tissues. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, or wood chips or fiber.

The earth contains about one trillion tonnes of wood, which grows at a rate of 10 billion tonnes per year. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy. In 1991, approximately 3.5 billion cubic meters of wood were harvested. Dominant uses were for furniture and building construction.^[2]

History[link]

A 2011 discovery in the Canadian province of New Brunswick uncovered the earliest known plants to have grown wood, approximately 395 to 400 million years ago.^[3]

People have used wood for millennia for many purposes, primarily as a fuel or as a construction material for making houses, tools, weapons, furniture, packaging, artworks, and paper.

Wood can be dated by carbon dating and in some species by dendrochronology to make inferences about when a wooden object was created.

The year-to-year variation in tree-ring widths and isotopic abundances gives clues to the prevailing climate at that time.^[4]

Physical properties[link]

Growth rings[link]

Wood, in the strict sense, is yielded by trees, which increase in diameter by the formation, between the existing wood and the inner bark, of new woody layers which envelop the entire stem, living branches, and roots. This process is known as secondary growth; it is the result of cell division in the vascular cambium, a lateral meristem, and subsequent expansion of the new cells. Where there are clear seasons, growth can occur in a discrete annual or seasonal pattern, leading to growth rings; these can usually be most clearly seen on the end of a log, but are also visible on the other surfaces. If these seasons are annual these growth rings are referred to as annual rings. Where there is no seasonal difference growth rings are likely to be indistinct or absent.

If there are differences within a growth ring, then the part of a growth ring nearest the center of the tree, and formed early in the growing season when growth is rapid, is usually composed of wider elements. It is usually lighter in color than that near the outer portion of the ring, and is known as earlywood or springwood. The outer portion formed later in the season is then known as the latewood or summerwood.^[5] However, there are major differences, depending on the kind of wood (see below).

Knots[link]

A knot on a tree at the Garden of the Gods public park in Colorado Springs, Colorado (October 2006)

A knot is a particular type of imperfection in a piece of wood; it will affect the technical properties of the wood, usually for the worse, but may be exploited for visual effect. In a longitudinally sawn plank, a knot will appear as a roughly circular "solid" (usually darker) piece of wood around which the grain of the rest of the wood "flows" (parts and rejoins). Within a knot, the direction of the wood (grain direction) is up to 90 degrees different from the grain direction of the regular wood.

In the tree a knot is either the base of a side branch or a dormant bud. A knot (when the base of a side branch) is conical in shape (hence the roughly circular cross-section) with the inner tip at the point in stem diameter at which the plant's vascular cambium was located when the branch formed as a bud.

During the development of a tree, the lower limbs often die, but may remain attached for a time, sometimes years. Subsequent layers of growth of the attaching stem are no longer intimately joined with the dead limb, but are grown around it. Hence, dead branches produce knots which are not attached, and likely to drop out after the tree has been sawn into boards.

In grading lumber and structural timber, knots are classified according to their form, size, soundness, and the firmness with which they are held in place. This firmness is affected by, among other factors, the length of time for which the branch was dead while the attaching stem continued to grow.

Wood Knot

Knots materially affect cracking and warping, ease in working, and cleavability of timber. They are defects which weaken timber and lower its value for structural purposes where strength is an important consideration. The weakening effect is much more serious when timber is subjected to forces perpendicular to the grain and/or tension than where under load along the grain and/or compression. The extent to which knots affect the strength of a beam depends upon their position, size, number, and condition. A knot on the upper side is compressed, while one on the lower side is subjected to tension. If there is a season check in the knot, as is often the case, it will offer little resistance to this tensile stress. Small knots, however, may be located along the neutral plane of a beam and increase the strength by preventing longitudinal shearing. Knots in a board or plank are least injurious when they extend through it at right angles to its broadest surface. Knots which occur near the ends of a beam do not weaken it. Sound knots which occur in the central portion one-fourth the height of the beam from either edge are not serious defects.^[6]

Knots do not necessarily influence the stiffness of structural timber, this will depend on the size and location. Stiffness and elastic strength are more dependent upon the sound wood than upon localized defects. The breaking strength is very susceptible to defects. Sound knots do not weaken wood when subject to compression parallel to the grain.

In some decorative applications, wood with knots may be desirable to add visual interest. In applications where wood is painted, such as skirting boards, fascia boards, door frames and furniture, resins present in the timber may continue to 'bleed' through to the surface of a knot for months or even years after manufacture and show as a yellow or brownish stain. A knot primer paint or solution, correctly applied during preparation, may do much to reduce this problem but it is difficult to control completely, especially when using mass-produced kiln-dried timber stocks.

Heartwood and sapwood[link]

A section of a Yew branch showing 27 annual growth rings, pale sapwood and dark heartwood, and pith (centre dark spot). The dark radial lines are small knots.

Heartwood (or duramen^[7]) is wood that as a result of a naturally occurring chemical transformation has become more resistant to decay. Heartwood formation occurs spontaneously (it is a genetically programmed process). Once heartwood formation is complete, the heartwood is dead.^[8] Some uncertainty still exists as to whether heartwood is truly dead, as it can still chemically react to decay organisms, but only once.^[9]

Usually heartwood looks different; in that case it can be seen on a cross-section, usually following the growth rings in shape. Heartwood may (or may not) be much darker than living wood. It may (or may not) be sharply distinct from the sapwood. However, other processes, such as decay, can discolor wood, even in woody plants that do not form heartwood, with a similar color difference, which may lead to confusion.

Sapwood (or alburnum^[7]) is the younger, outermost wood; in the growing tree it is living wood,^[8] and its principal functions are to conduct water from the roots to the leaves and to store up and give back according to the season the reserves prepared in the leaves. However, by the time they become competent to conduct water, all xylem tracheids and vessels have lost their cytoplasm and the cells are therefore functionally dead. All wood in a tree is first formed as sapwood. The more leaves a tree bears and the more vigorous its growth, the larger the volume of sapwood required. Hence trees making rapid growth in the open have thicker sapwood for their size than trees of the same species growing in dense forests. Sometimes trees (of species that do form heartwood) grown in the open may become of considerable size, 30 cm or more in diameter, before any heartwood begins to form, for example, in second-growth hickory, or open-grown pines.

The term heartwood derives solely from its position and not from any vital importance to the tree. This is evidenced by the fact that a tree can thrive with its heart completely decayed. Some species begin to form heartwood very early in life, so having only a thin layer of live sapwood, while in others the change comes slowly. Thin sapwood is characteristic of such species as chestnut, black locust, mulberry, osage-orange, and sassafras, while in maple, ash, hickory, hackberry, beech, and pine, thick sapwood is the rule. Others never form heartwood.

No definite relation exists between the annual rings of growth and the amount of sapwood. Within the same species the cross-sectional area of the sapwood is very roughly proportional to the size of the crown of the tree. If the rings are narrow, more of them are required than where they are wide. As the tree gets larger, the sapwood must necessarily become thinner or increase materially in volume. Sapwood is thicker in the upper portion of the trunk of a tree than near the base, because the age and the diameter of the upper sections are less.

When a tree is very young it is covered with limbs almost, if not entirely, to the ground, but as it grows older some or all of them will eventually die and are either broken off or fall off. Subsequent growth of wood may completely conceal the stubs which will however remain as knots. No matter how smooth and clear a log is on the outside, it is more or less knotty near the middle. Consequently the sapwood of an old tree, and particularly of a forest-grown tree, will be freer from knots than the inner heartwood. Since in most uses of wood, knots are defects that weaken the timber and interfere with its ease of working and other properties, it follows that a given piece of sapwood, because of its position in the tree, may well be stronger than a piece of heartwood from the same tree.

It is remarkable that the inner heartwood of old trees remains as sound as it usually does, since in many cases it is hundreds, and in a few instances thousands, of years old. Every broken limb or root, or deep wound from fire, insects, or falling timber, may afford an entrance for decay, which, once started, may penetrate to all parts of the trunk. The larvae of many insects bore into the trees and their tunnels remain indefinitely as sources of weakness. Whatever advantages, however, that sapwood may have in this connection are due solely to its relative age and position.

If a tree grows all its life in the open and the conditions of soil and site remain unchanged, it will make its most rapid growth in youth, and gradually decline. The annual rings of growth are for many years quite wide, but later they become narrower and narrower. Since each succeeding ring is laid down on the outside of the wood previously formed, it follows that unless a tree materially increases its production of wood from year to year, the rings must necessarily become thinner as the trunk gets wider. As a tree reaches maturity its crown becomes more open and the annual wood production is lessened, thereby reducing still more the width of the growth rings. In the case of forest-grown trees so much depends upon the competition of the trees in their struggle for light and nourishment that periods of rapid and slow growth may alternate. Some trees, such as southern oaks, maintain the same width of ring for hundreds of years. Upon the whole, however, as a tree gets larger in diameter the width of the growth rings decreases.

Different pieces of wood cut from a large tree may differ decidedly, particularly if the tree is big and mature. In some trees, the wood laid on late in the life of a tree is softer, lighter, weaker, and more even-textured than that produced earlier, but in other trees, the reverse applies. This may or may not correspond to heartwood and sapwood. In a large log the sapwood, because of the time in the life of the tree when it was grown, may be inferior in hardness, strength, and toughness to equally sound heartwood from the same log. In a smaller tree, the reverse may be true.

Color[link]

In species which show a distinct difference between heartwood and sapwood the natural color of heartwood is usually darker than that of the sapwood, and very frequently the contrast is conspicuous (see section of yew log above). This is produced by deposits in the heartwood of chemical substances, so that a dramatic color difference does not mean a dramatic difference in the mechanical properties of heartwood and sapwood, although there may be a dramatic chemical difference.

Some experiments on very resinous Longleaf Pine specimens indicate an increase in strength, due to the resin which increases the strength when dry. Such resin-saturated heartwood is called "fat lighter". Structures built of fat lighter are almost impervious to rot and termites; however they are very flammable. Stumps of old longleaf pines are often dug, split into small pieces and sold as kindling for fires. Stumps thus dug may actually remain a century or more since being cut. Spruce impregnated with crude resin and dried is also greatly increased in strength thereby.

The wood of Coast Redwood is distinctively red in color

Since the latewood of a growth ring is usually darker in color than the earlywood, this fact may be used in judging the density, and therefore the hardness and strength of the material. This is particularly the case with coniferous woods. In ring-porous woods the vessels of the early wood not infrequently appear on a finished surface as darker than the denser latewood, though on cross sections of heartwood the reverse is commonly true. Except in the manner just stated the color of wood is no indication of strength.

Abnormal discoloration of wood often denotes a diseased condition, indicating unsoundness. The black check in western hemlock is the result of insect attacks. The reddish-brown streaks so common in hickory and certain other woods are mostly the result of injury by birds. The discoloration is merely an indication of an injury, and in all probability does not of itself affect the properties of the wood. Certain rot-producing fungi impart to wood characteristic colors which thus become symptomatic of weakness; however an attractive effect known as spalting produced by this process is often considered a desirable characteristic. Ordinary sap-staining is due to fungal growth, but does not necessarily produce a weakening effect.

Water content[link]

Water occurs in living wood in three conditions, namely: (1) in the cell walls, (2) in the protoplasmic contents of the cells, and (3) as free water in the cell cavities and spaces. In heartwood it occurs only in the first and last forms. Wood that is thoroughly air-dried retains 8–16% of the water in the cell walls, and none, or practically none, in the other forms. Even oven-dried wood retains a small percentage of moisture, but for all except chemical purposes, may be considered absolutely dry.

The general effect of the water content upon the wood substance is to render it softer and more pliable. A similar effect of common observation is in the softening action of water on paper or cloth. Within certain limits, the greater the water content, the greater its softening effect.

Drying produces a decided increase in the strength of wood, particularly in small specimens. An extreme example is the case of a completely dry spruce block 5 cm in section, which will sustain a permanent load four times as great as a green (undried) block of the same size will.^{[citation needed]}

The greatest strength increase due to drying is in the ultimate crushing strength, and strength at elastic limit in endwise compression; these are followed by the modulus of rupture, and stress at elastic limit in cross-bending, while the modulus of elasticity is least affected.

Structure[link]

Wood is a heterogeneous, hygroscopic, cellular and anisotropic material. It is composed of cells, and the cell walls are composed of micro-fibrils of cellulose (40% – 50%) and hemicellulose (15% – 25%) impregnated with lignin (15% – 30%).^[10]

Sections of tree trunk

A tree trunk as found at the Veluwe, Netherlands

In coniferous or softwood species the wood cells are mostly of one kind, tracheids, and as a result the material is much more uniform in structure than that of most hardwoods. There are no vessels ("pores") in coniferous wood such as one sees so prominently in oak and ash, for example.

The structure of hardwoods is more complex.^[11] The water conducting capability is mostly taken care of by vessels: in some cases (oak, chestnut, ash) these are quite large and distinct, in others (buckeye, poplar, willow) too small to be seen without a hand lens. In discussing such woods it is customary to divide them into two large classes, ring-porous and diffuse-porous. In ring-porous species, such as ash, black locust, catalpa, chestnut, elm, hickory, mulberry, and oak, the larger vessels or pores (as cross sections of vessels are called) are localised in the part of the growth ring formed in spring, thus forming a region of more or less open and porous tissue. The rest of the ring, produced in summer, is made up of smaller vessels and a much greater proportion of wood fibers. These fiber are the elements which give strength and toughness to wood, while the vessels are a source of weakness.

Magnified cross-section of Black Walnut, showing the vessels, rays (white lines) and annual rings: this is intermediate between diffuse-porous and ring-porous, with vessel size declining gradually

In diffuse-porous woods the pores are evenly sized so that the water conducting capability is scattered throughout the growth ring instead of being collected in a band or row. Examples of this kind of wood are basswood, birch, buckeye, maple, poplar, and willow. Some species, such as walnut and cherry, are on the border between the two classes, forming an intermediate group.

Earlywood and latewood in softwood[link]

earlywood and latewood in a softwood; radial view, growth rings closely spaced in a Pseudotsuga taxifolia

In temperate softwoods there often is a marked difference between latewood and earlywood. The latewood will be denser than that formed early in the season. When examined under a microscope the cells of dense latewood are seen to be very thick-walled and with very small cell cavities, while those formed first in the season have thin walls and large cell cavities. The strength is in the walls, not the cavities. Hence the greater the proportion of latewood the greater the density and strength. In choosing a piece of pine where strength or stiffness is the important consideration, the principal thing to observe is the comparative amounts of earlywood and latewood. The width of ring is not nearly so important as the proportion and nature of the latewood in the ring.

If a heavy piece of pine is compared with a lightweight piece it will be seen at once that the heavier one contains a larger proportion of latewood than the other, and is therefore showing more clearly demarcated growth rings. In white pines there is not much contrast between the different parts of the ring, and as a result the wood is very uniform in texture and is easy to work. In hard pines, on the other hand, the latewood is very dense and is deep-colored, presenting a very decided contrast to the soft, straw-colored earlywood.

It is not only the proportion of latewood, but also its quality, that counts. In specimens that show a very large proportion of latewood it may be noticeably more porous and weigh considerably less than the latewood in pieces that contain but little. One can judge comparative density, and therefore to some extent strength, by visual inspection.

No satisfactory explanation can as yet be given for the exact mechanisms determining the formation of earlywood and latewood. Several factors may be involved. In conifers, at least, rate of growth alone does not determine the proportion of the two portions of the ring, for in some cases the wood of slow growth is very hard and heavy, while in others the opposite is true. The quality of the site where the tree grows undoubtedly affects the character of the wood formed, though it is not possible to formulate a rule governing it. In general, however, it may be said that where strength or ease of working is essential, woods of moderate to slow growth should be chosen.

Earlywood and latewood in ring-porous woods[link]

Earlywood and latewood in a ring-porous wood (ash) in a Fraxinus excelsior ; tangential view, wide growth rings

In ring-porous woods each season's growth is always well defined, because the large pores formed early in the season abut on the denser tissue of the year before.

In the case of the ring-porous hardwoods there seems to exist a pretty definite relation between the rate of growth of timber and its properties. This may be briefly summed up in the general statement that the more rapid the growth or the wider the rings of growth, the heavier, harder, stronger, and stiffer the wood. This, it must be remembered, applies only to ring-porous woods such as oak, ash, hickory, and others of the same group, and is, of course, subject to some exceptions and limitations.

In ring-porous woods of good growth it is usually the latewood in which the thick-walled, strength-giving fibers are most abundant. As the breadth of ring diminishes, this latewood is reduced so that very slow growth produces comparatively light, porous wood composed of thin-walled vessels and wood parenchyma. In good oak these large vessels of the earlywood occupy from 6 to 10 percent of the volume of the log, while in inferior material they may make up 25% or more. The latewood of good oak is dark colored and firm, and consists mostly of thick-walled fibers which form one-half or more of the wood. In inferior oak, this latewood is much reduced both in quantity and quality. Such variation is very largely the result of rate of growth.

Wide-ringed wood is often called "second-growth", because the growth of the young timber in open stands after the old trees have been removed is more rapid than in trees in a closed forest, and in the manufacture of articles where strength is an important consideration such "second-growth" hardwood material is preferred. This is particularly the case in the choice of hickory for handles and spokes. Here not only strength, but toughness and resilience are important. The results of a series of tests on hickory by the U.S. Forest Service show that:

"The work or shock-resisting ability is greatest in wide-ringed wood that has from 5 to 14 rings per inch (rings 1.8-5 mm thick), is fairly constant from 14 to 38 rings per inch (rings 0.7–1.8 mm thick), and decreases rapidly from 38 to 47 rings per inch (rings 0.5–0.7 mm thick). The strength at maximum load is not so great with the most rapid-growing wood; it is maximum with from 14 to 20 rings per inch (rings 1.3–1.8 mm thick), and again becomes less as the wood becomes more closely ringed. The natural deduction is that wood of first-class mechanical value shows from 5 to 20 rings per inch (rings 1.3–5 mm thick) and that slower growth yields poorer stock. Thus the inspector or buyer of hickory should discriminate against timber that has more than 20 rings per inch (rings less than 1.3 mm thick). Exceptions exist, however, in the case of normal growth upon dry situations, in which the slow-growing material may be strong and tough."^[12]

The effect of rate of growth on the qualities of chestnut wood is summarised by the same authority as follows:

"When the rings are wide, the transition from spring wood to summer wood is gradual, while in the narrow rings the spring wood passes into summer wood abruptly. The width of the spring wood changes but little with the width of the annual ring, so that the narrowing or broadening of the annual ring is always at the expense of the summer wood. The narrow vessels of the summer wood make it richer in wood substance than the spring wood composed of wide vessels. Therefore, rapid-growing specimens with wide rings have more wood substance than slow-growing trees with narrow rings. Since the more the wood substance the greater the weight, and the greater the weight the stronger the wood, chestnuts with wide rings must have stronger wood than chestnuts with narrow rings. This agrees with the accepted view that sprouts (which always have wide rings) yield better and stronger wood than seedling chestnuts, which grow more slowly in diameter."^[12]

Earlywood and latewood in diffuse-porous woods[link]

In the diffuse-porous woods, the demarcation between rings is not always so clear and in some cases is almost (if not entirely) invisible to the unaided eye. Conversely, when there is a clear demarcation there may not be a noticeable difference in structure within the growth ring.

In diffuse-porous woods, as has been stated, the vessels or pores are even-sized, so that the water conducting capability is scattered throughout the ring instead of collected in the earlywood. The effect of rate of growth is, therefore, not the same as in the ring-porous woods, approaching more nearly the conditions in the conifers. In general it may be stated that such woods of medium growth afford stronger material than when very rapidly or very slowly grown. In many uses of wood, total strength is not the main consideration. If ease of working is prized, wood should be chosen with regard to its uniformity of texture and straightness of grain, which will in most cases occur when there is little contrast between the latewood of one season's growth and the earlywood of the next.

Monocot wood[link]

Trunks of the Coconut palm, a monocot, in Java. From this perspective these look not much different from trunks of a dicot or conifer

Structural material that roughly (in its gross handling characteristics) resembles ordinary, "dicot" or conifer wood is produced by a number of monocot plants, and these also are colloquially called wood. Of these, bamboo, botanically a member of the grass family, has considerable economic importance, larger culms being widely used as a building and construction material in their own right and, these days, in the manufacture of engineered flooring, panels and veneer. Another major plant group that produce material that often is called wood are the palms. Of much less importance are plants such as Pandanus, Dracaena and Cordyline. With all this material, the structure and composition of the structural material is quite different from ordinary wood.

Hard and soft woods[link]

There is a strong relationship between the properties of wood and the properties of the particular tree that yielded it. The density of wood varies with species. The density of a wood correlates with its strength (mechanical properties). For example, mahogany is a medium-dense hardwood that is excellent for fine furniture crafting, whereas balsa is light, making it useful for model building. One of the densest woods is black ironwood.

It is common to classify wood as either softwood or hardwood. The wood from conifers (e.g. pine) is called softwood, and the wood from dicotyledons (usually broad-leaved trees, e.g. oak) is called hardwood. These names are a bit misleading, as hardwoods are not necessarily hard, and softwoods are not necessarily soft. The well-known balsa (a hardwood) is actually softer than any commercial softwood. Conversely, some softwoods (e.g. yew) are harder than many hardwoods.

Chemistry of wood[link]

Aside from water, wood has three main components. Cellulose, a crystalline polymer derived from glucose, constitutes about 41–43%. Next in abundance is hemicellulose, which is around 20% in deciduous trees but near 30% in conifers. It is mainly five-carbon sugars that are linked in an irregular manner, in contrast to the cellulose. Lignin is the third component at around 27% in coniferous wood vs 23% in deciduous trees. Lignin confers the hydrophobic properties reflecting the fact that it is based on aromatic rings. These three components are interwoven, and direct covalent linkages exist between the lignin and the hemicellulose. A major focus of the paper industry is the separation of the lignin from the cellulose, from which paper is made.

Chemical structure of lignin, which comprises approximately 30% of wood and is responsible for many of its properties.

In chemical terms, the difference between hardwood and softwood is reflected in the composition of the constituent lignin. Hardwood lignin is primarily derived from sinapyl alcohol and coniferyl alcohol. Softwood lignin is mainly derived from coniferyl alcohol.^[13]

Extractives[link]

Aside from the lignocellulose, wood consists of a variety of low molecular weight organic compounds, called extractives. The wood extractives are fatty acids, resin acids, waxes and terpenes.^[14] For example, rosin is exuded by conifers as protection from insects. The extraction of these organic materials from wood provides tall oil, terpentine, and rosin.^[15]

Uses[link]

Fuel[link]

Wood has a long history of being used as fuel, which continues to this day, mostly in rural areas of the world. Hardwood is preferred over softwood because it creates less smoke and burns longer. Adding a woodstove or fireplace to a home is often felt to add ambiance and warmth.^[16]

The churches of Kizhi, Russia are among a handful of World Heritage Sites built entirely of wood, without metal joints. See Kizhi Pogost for more details.

The complex carpentry of the Centre Pompidou-Metz museum, Metz.

Construction[link]

Wood has been an important construction material since humans began building shelters, houses and boats. Nearly all boats were made out of wood until the late 19th century, and wood remains in common use today in boat construction.

Wood to be used for construction work is commonly known as lumber in North America. Elsewhere, lumber usually refers to felled trees, and the word for sawn planks ready for use is timber.

New domestic housing in many parts of the world today is commonly made from timber-framed construction. Engineered wood products are becoming a bigger part of the construction industry. They may be used in both residential and commercial buildings as structural and aesthetic materials.

In buildings made of other materials, wood will still be found as a supporting material, especially in roof construction, in interior doors and their frames, and as exterior cladding.

Wood is also commonly used as shuttering material to form the mould into which concrete is poured during reinforced concrete construction.

Furniture and utensils[link]

Wood has always been used extensively for furniture, such as chairs and beds. Also for tool handles and cutlery, such as chopsticks, toothpicks, and other utensils, like the wooden spoon.

Engineered wood[link]

Wood can be cut into straight planks and made into a wood flooring.

Engineered wood products, glued building products "engineered" for application-specific performance requirements, are often used in construction and industrial applications. Glued engineered wood products are manufactured by bonding together wood strands, veneers, lumber or other forms of wood fiber with glue to form a larger, more efficient composite structural unit.^[18] These products include glued laminated timber (glulam), wood structural panels (including plywood, oriented strand board and composite panels), laminated veneer lumber (LVL) and other structural composite lumber (SCL) products, parallel strand lumber, and I-joists.^[18] Approximately 100 million cubic meters of wood was consumed for this purpose in 1991.^[2] The trends suggest that particle board and fiber board will overtake plywood.

Engineered wood products display highly predictable and reliable performance characteristics and provide enhanced design flexibility: on one hand, these products allow the use of smaller pieces, and on the other hand, they allow for bigger spans. They may also be selected for specific projects such as public swimming pools or ice rinks where the wood will not deteriorate in the presence of certain chemicals, and are less susceptible to the humidity changes commonly found in these environments.

Engineered wood products prove to be more environmentally friendly and, if used appropriately, are often less expensive than building materials such as steel or concrete. These products are extremely resource-efficient because they use more of the available resource with minimal waste. In most cases, engineered wood products are produced using faster growing and often underutilized wood species from managed forests and tree farms.^[19]

Wood unsuitable for construction in its native form may be broken down mechanically (into fibers or chips) or chemically (into cellulose) and used as a raw material for other building materials, such as engineered wood, as well as chipboard, hardboard, and medium-density fiberboard (MDF). Such wood derivatives are widely used: wood fibers are an important component of most paper, and cellulose is used as a component of some synthetic materials. Wood derivatives can also be used for kinds of flooring, for example laminate flooring.

Next generation wood products[link]

Further developments include new lignin glue applications, recyclable food packaging, rubber tire replacement applications, anti-bacterial medical agents, and high strength fabrics or composites.^[20] As scientists and engineers further learn and develop new techniques to extract various components from wood, or alternatively to modify wood, for example by adding components to wood, new more advanced products will appear on the marketplace.

In the arts[link]

Artists can use wood to create delicate sculptures.

Stringed instrument bows are often made from pernambuco or brazilwood.

Wood has long been used as an artistic medium. It has been used to make sculptures and carvings for millennia. Examples include the totem poles carved by North American indigenous people from conifer trunks, often Western Red Cedar (Thuja plicata), and the Millennium clock tower,^[21] now housed in the National Museum of Scotland^[22] in Edinburgh.

It is also used in woodcut printmaking, and for engraving.

Certain types of musical instruments, such as those of the violin family, the guitar, the clarinet and recorder, the xylophone, and the marimba, are made mostly or entirely of wood. The choice of wood may make a significant difference to the tone and resonant qualities of the instrument, and tonewoods have widely differing properties, ranging from the hard and dense african blackwood (used for the bodies of clarinets) to the light but resonant European spruce (Picea abies) (traditionally used for the soundboards of violins). The most valuable tonewoods, such as the ripple sycamore (Acer pseudoplatanus), used for the backs of violins, combine acoustic properties with decorative color and grain which enhance the appearance of the finished instrument.

Despite their collective name, not all woodwind instruments are made entirely of wood. The reeds used to play them, however, are usually made from Arundo donax, a type of monocot cane plant.

Sports and recreational equipment[link]

Many types of sports equipment are made of wood, or were constructed of wood in the past. For example, cricket bats are typically made of white willow. The baseball bats which are legal for use in Major League Baseball are frequently made of ash wood or hickory, and in recent years have been constructed from maple even though that wood is somewhat more fragile. In softball, however, bats are more commonly made of aluminium (this is especially true for fastpitch softball).

Many other types of sports and recreation equipment, such as skis, ice hockey sticks, lacrosse sticks and archery bows, were commonly made of wood in the past, but have since been replaced with more modern materials such as aluminium, fiberglass, carbon fiber, titanium, and composite materials. One noteworthy example of this trend is the golf club commonly known as the wood, the head of which was traditionally made of persimmon wood in the early days of the game of golf, but is now generally made of synthetic materials.

Medicine[link]

In January 2010 Italian scientists announced that wood could be harnessed to become a bone substitute. It is likely to take at least five years until this technique will be applied for humans.^[23]

See also[link]

Notes[link]

References[link]

Trees portal

Wikimedia Commons has media related to: Wood

Look up wood in Wiktionary, the free dictionary.

v t e Botany Subdisciplines of botany Ethnobotany Paleobotany Plant anatomy Plant ecology Plant evo-devo Plant morphology Plant physiology Plants Evolutionary history of plants Algae Bryophyte Pteridophyte Gymnosperm Angiosperm Plant parts Flower Fruit Leaf Meristem Root Stem Stoma Vascular tissue Wood Plant cells Cell wall Chlorophyll Chloroplast Photosynthesis Plant hormone Plastid Transpiration Plant reproduction Alternation of generations Gametophyte Plant sexuality Pollen Pollination Seed Spore Sporophyte Plant taxonomy Botanical name Botanical nomenclature Herbarium IAPT ICN Species Plantarum Glossaries Glossary of botanical terms Glossary of plant morphology terms Category Portal

Golf

A golfer in the finishing position after taking a "tee shot"
Highest governing body	R&A USGA
First played	15th century, Scotland
Characteristics
Contact	No
Categorization	Outdoor
Equipment	Golf clubs, golf ball
Olympic	1900, 1904, 2016,[1] 2020[2]

Golf is a precision club and ball sport, in which competing players (or golfers) use many types of clubs to hit balls into a series of holes on a golf course using the fewest number of strokes.

It is one of the few ball games that does not require a standardized playing area. Instead, the game is played on golf "courses", each of which features a unique design, although courses typically consist of either nine or 18 holes. Golf is defined, in the rules of golf, as "playing a ball with a club from the teeing ground into the hole by a stroke or successive strokes in accordance with the Rules."

Golf competition is generally played for the lowest number of strokes by an individual, known simply as stroke play, or the lowest score on the most individual holes during a complete round by an individual or team, known as match play.

Origin[link]

While the modern game of golf originated in 15th century Scotland, the game's ancient origins are unclear and much debated. Some historians^[3] trace the sport back to the Roman game of paganica, in which participants used a bent stick to hit a stuffed leather ball. One theory asserts that paganica spread throughout Europe as the Romans conquered most of the continent, during the first century BC, and eventually evolved into the modern game.^[4] Others cite chuiwan ("chui" means striking and "wan" means small ball) as the progenitor, a Chinese game played between the eighth and 14th centuries.^[5] A Ming Dynasty scroll dating back to 1368 entitled "The Autumn Banquet" shows a member of the Chinese Imperial court swinging what appears to be a golf club at a small ball with the aim of sinking it into a hole. The game is thought to have been introduced into Europe during the Middle Ages. Another early game that resembled modern golf was known as cambuca in England and chambot in France.^[6] This game was, in turn, exported to the Low Countries, Germany, and England (where it was called pall-mall, pronounced “pell mell”).^{[citation needed]} Some observers,^[who?] however, believe that golf descended from the Persian game, chaugán. In addition, kolven (a game involving a ball and curved bats) was played annually in Loenen, Netherlands, beginning in 1297, to commemorate the capture of the assassin of Floris V, a year earlier.

The modern game originated in Scotland, where the first written record of golf is James II's banning of the game in 1457, as an unwelcome distraction to learning archery.^[7] To many golfers, the Old Course at St Andrews, a links course dating to before 1574, is considered to be a site of pilgrimage.^[8] Golf is documented as being played on Musselburgh Links, East Lothian, Scotland as early as 2 March 1672, which is certified as the oldest golf course in the world by Guinness World Records.^[9][10] The oldest surviving rules of golf were compiled in March 1744 for the Company of Gentlemen Golfers, later renamed The Honourable Company of Edinburgh Golfers, which was played at Leith, Scotland.^[11] The world's oldest golf tournament in existence, and golf's first major, is The Open Championship, which was first played on 17 October 1860 at Prestwick Golf Club, in Ayrshire, Scotland.^[12]

Golf course[link]

A golf course consists of a series of holes, each with a teeing ground that is set off by two markers showing the bounds of the legal tee area, fairway, rough and other hazards, and the putting green surrounded by the fringe with the pin (normally a flagstick) and cup.

The levels of grass are varied to increase difficulty, or to allow for putting in the case of the green. While many holes are designed with a direct line-of-sight from the teeing area to the green, some holes may bend either to the left or to the right. This is commonly called a "dogleg", in reference to a dog's knee. The hole is called a "dogleg left" if the hole angles leftwards and "dogleg right" if it bends right. Sometimes, a hole's direction may bend twice; this is called a "double dogleg".

A typical golf course consists of 18 holes, but nine-hole courses are common and can be played twice through for a full round of 18 holes.^[13][14]

Early Scottish golf courses were primarily laid out on links land, soil-covered sand dunes directly inland from beaches.^[15] This gave rise to the term "golf links", particularly applied to seaside courses and those built on naturally sandy soil inland.

The first 18-hole golf course in the United States was located on a sheep farm in Downers Grove, Illinois, in 1892. The course is still situated there today.^[16]

Play of the game[link]

1=teeing ground, 2=water hazard, 3=rough, 4=out of bounds, 5=sand bunker, 6=water hazard, 7=fairway, 8=putting green, 9=flagstick, 10=hole

Every round of golf is based on playing a number of holes in a given order. A 'round' typically consists of 18 holes that are played in the order determined by the course layout. On a nine-hole course, a standard round consists of two consecutive nine-hole rounds.

Playing a hole on a golf course is initiated by putting a ball into play by striking it with a club on the teeing ground (also called the tee box, or simply the tee). When this initial stroke (or 'shot') is required to be long due to the length of the hole, it is usual (but not required) for a golfer to suspend (or 'tee-up') the ball on a tee prior to striking it. A tee in this last sense is a small peg which can be used to elevate the ball slightly above the ground up to a few centimetres high. This elevation is at the discretion of the golfer. Tees are commonly made of wood but may be constructed of any material; the ball may even be teed on a mound of grass or dirt (at one time a small pile of sand placed by the golfer was routinely used and sand was provided at teeing grounds for golfers' use).

When the initial shot on a hole is a long-distance shot intended to move the ball a great distance down the fairway, this shot is commonly called a 'drive'. Shorter holes generally are initiated with shorter clubs called irons. Once the ball comes to rest, the golfer strikes it again as many times as necessary using shots that are variously known as a 'lay-up', an 'approach', a 'pitch', or a 'chip', until the ball reaches the green, where he or she then 'putts' the ball into the hole (commonly called "sinking the putt"). The goal of getting the ball into the hole ("holing" the ball) in as few strokes as possible may be impeded by obstacles such as areas of long grass called 'rough' (usually found alongside fairways) which both slows any ball that contacts it and makes it harder to advance a ball that has stopped on it, bunkers (or sand traps), and water hazards.^[13] In most forms of gameplay, each player plays his or her ball until it is holed.

Players can walk to their next shot or drive in golf carts over the course. The game can be played either individually or in groups and sometimes accompanied by caddies, who carry and manage the players' equipment and who are allowed by the rules to give advice on the play of the course.^[17] A caddy's advice can only be given to the player or players for whom the caddy is working, and not to competing players.

Rules and regulations[link]

The rules of golf are internationally standardised and are jointly governed by The R&A, spun off in 2004 from The Royal and Ancient Golf Club of St Andrews (founded 1754), and the United States Golf Association (USGA).^[18][19]

The underlying principle of the rules is fairness. As stated on the back cover of the official rule book:

Play the ball as it lies, play the course as you find it, and if you cannot do either, do what is fair.

There are strict regulations regarding the amateur status of golfers.^[20] Essentially, anybody who has ever received payment or compensation for giving instruction, or played golf for money, is not considered an amateur and may not participate in competitions limited solely to amateurs. However, amateur golfers may receive expenses which comply with strict guidelines and they may accept non-cash prizes within the limits established by the Rules of Amateur Status.

In addition to the officially printed rules, golfers also abide by a set of guidelines called golf etiquette. Etiquette guidelines cover matters such as safety, fairness, pace of play, and a player's obligation to contribute to the care of the course. Though there are no penalties for breach of etiquette rules, players generally follow the rules of golf etiquette in an effort to improve everyone's playing experience.

Penalties[link]

Penalties are incurred in certain situations. They are counted towards a player's score as if there were extra swing(s) at the ball. Strokes are added for rule infractions or for hitting one's ball into an unplayable situation.

A lost ball or a ball hit out of bounds result in a penalty of one stroke and distance (Rule 27–1). A one-stroke penalty is assessed if a player's equipment causes the ball to move or the removal of a loose impediment causes the ball to move (Rule 18–2). If a golfer makes a stroke at the wrong ball (Rule 19–2) or hits a fellow golfer's ball with a putt (Rule 19–5), the player incurs a two-stroke penalty. Most rule infractions lead to stroke penalties but also can lead to disqualification. Disqualification could be from cheating, signing for a lower score, or from rule infractions that lead to improper play.^[21]

Equipment[link]

A wood positioned ready to be swung and to strike a golf ball

Golf clubs are used to hit the golf ball. Each club is composed of a shaft with a lance (or 'grip') on the top end and a club head on the bottom. Long clubs, which have a lower amount of degreed loft, are those meant to propel the ball a comparatively longer distance, and short clubs a higher degree of loft and a comparatively shorter distance. Typically, the actual physical length of each club is longer or shorter, depending on the distance the club is intended to propel the ball.

The 'driver' is the largest-headed and longest club. Woods are slightly shorter but still comparatively large-headed clubs, used for long-distance fairway shots. Woods are now typically made of metal; the traditional name remains in general use but is gradually being replaced by the term "fairway metal".^{[citation needed]} Next shorter in length are the irons, the most numerous and versatile class used for a wide variety of shots. Hybrids embody the characteristics of both woods and irons in varying degrees and are increasingly being used in preference to long irons in many places because they are easier for the average golfer to use. Finally, the putter is used to roll the ball across the green into the cup.

A maximum of 14 clubs is allowed in a player's bag at one time during a stipulated round. The choice of clubs is at the golfer's discretion, although every club must be constructed in accordance with parameters outlined in the rules. (Clubs which meet these parameters are usually called 'conforming'.) Violation of these rules can result in disqualification.

The exact shot hit at any given time on a golf course, and which club is used to accomplish the shot, are always completely at the discretion of the golfer; in other words, there is no restriction whatsoever on which club a golfer may or may not use at any time for any shot.

Golf balls are spherical, usually white (although other colors are allowed), and minutely pock-marked by dimples that decrease aerodynamic drag by increasing air turbulence around the ball in motion, preventing "boundary layer" separation, thereby allowing the ball to fly farther.^[22]

A tee is allowed only for the first stroke on each hole, unless the player must hit a provisional tee shot or replay his or her first shot from the tee.

Many golfers wear golf shoes with metal or plastic spikes designed to increase traction, thus allowing for longer and more accurate shots. A golf bag is used to transport golf clubs and the player's other or personal equipment. Golf bags have several pockets designed for carrying equipment and supplies such as tees, balls, and gloves. Golf bags can be carried, pulled on a trolley or harnessed to a motorized golf cart during play. Golf bags have both a hand strap and shoulder strap for carrying, and sometimes have retractable legs that allow the bag to stand upright when at rest.

Stroke mechanics[link]

A golfer takes an approach shot on the fairway.

Golfers start with the non-dominant side of the body facing the target. At address the body and club are positioned parallel to the target line. The feet are commonly shoulder-width apart for middle irons and putters, narrower for short irons and wider for long irons and woods. The ball is positioned in the centre of the player's stance for short irons and putters, more to the front for middle irons and even more for long irons and woods. The golfer chooses a golf club, grip, and stroke appropriate to the distance:

• The drive is used on the teeing ground to tee-off long distances;
• The approach is used in long- to mid-distance shots;
• The chip is used for relatively short-distance shots around the green. The goal of the chip is to land the ball safely on the green allowing it to roll out towards the hole.
• The putt is used in short-distance shots on or near the green. The goal of the putt is to get the ball in the hole.

Scoring and handicapping[link]

Par[link]

A par-3 hole in Phoenician Golf Club, Scottsdale, Arizona

A hole is classified by its par, meaning the number of strokes a skilled golfer should require to complete play of the hole.^[13] Par always includes a stroke for the tee shot and two putts, so the minimum par of any hole is 3. For example, a skilled golfer expects to reach the green on a par-4 hole in two strokes: one from the tee (the 'drive') and another, second, stroke to the green (the 'approach'); and then roll the ball into the hole in two putts for par. This would be termed a 'green in regulation' (GIR). A hole is either a par-3, −4 or −5. Par-6 holes are extremely rare.^[23]

The key factor for classifying the par of a hole is the distance from the tee to the green. A typical par-3 hole is less than 250 yards (225 m) in length, with a par-4 hole ranging between 251 and 475 yards (225–434 m), and a par-5 hole being longer than 475 yards (435 m). The rare par-6s can stretch well over 650 yards (595 m).

The gradient of the hole can also affect its par. If the tee-to-green distance on a hole is predominantly downhill, it will play shorter than its physical length and may be given a lower par; the opposite is true for uphill holes. Par ratings are also affected by factors such as the placement of hazards or the shape of the green, which can affect the play of a hole by requiring an extra stroke to avoid playing into hazards.^[24]

Eighteen-hole courses typically total to an overall par score of 72 for a complete round; this would be four par-3, ten par-4, and four par-5 holes, though other combinations exist and are not less worthy than courses of par-72. Many major championships are contested on courses playing to a par of 70, 71, or 72. Additionally, in some countries, courses are classified according to their play difficulty, which may be used to calculate a golfer's playing handicap for a given course.^[25]

Scoring[link]

In every form of play, the goal is to play as few strokes per round as possible. A hole in one (or an 'ace') occurs when a golfer sinks his ball into the cup with his first stroke from the tee. Common scores for a hole also have specific terms.^[13]

Basic forms of golf[link]

Match play[link]

In match play, two players (or two teams) play each hole as a separate contest against each other. The party with the lower score wins that hole, or if the scores of both players or teams are equal the hole is 'halved' (or tied). The game is won by the party that wins more holes than the other. In the case that one team or player has taken a lead that cannot be overcome in the number of holes remaining to be played, the match is deemed to be won by the party in the lead, and the remainder of the holes are not played. For example, if one party already has a lead of six holes, and only five holes remain to be played on the course, the match is over and the winning party is deemed to have won "6 & 5". At any given point, if the lead is equal to the number of holes remaining, the party leading the match is said to be 'dormie', and the match is continued until the party increases the lead by one hole or ties any of the remaining holes, thereby winning the match, or until the match ends in a tie with the lead player's opponent winning all remaining holes. When the game is tied after the predetermined number of holes have been played, it may be continued until one side takes a one-hole lead.^[13]

Stroke play[link]

In stroke play, the score achieved for each and every hole of the round or tournament is added to produce the total score, and the player with the lowest score wins. Stroke play is the game most commonly played by professional golfers. If there is a tie after the regulation number of holes in a professional tournament, a playoff takes place between all tied players. Playoffs are either sudden death or employ a pre-determined number of holes, anywhere from three to a full 18. In sudden death, a player who scores lower on a hole than all of his opponents wins the match. If at least two players remain tied after such a playoff using a pre-determined number of holes, then play continues in sudden death format, where the first player to win a hole wins the tournament.

Other forms of play[link]

Skins[link]

In a skins game, golfers compete on each hole, as a separate contest. Played for prize money on the professional level or as a means of a wager for amateurs, a 'skin', or the prize money assigned to each hole, carries over to subsequent holes if the hole is tied (or halved). If players come to the end of the round and there are still skins left to decide, play continues with playoff holes (typically repeating the 18th hole) until the final skin has been decided.

9-Points[link]

This unreferenced section requires citations to ensure verifiability.

In a 9-Point game three players compete for points on each hole. The player with the most points at the end of the round wins the game. Each hole is worth a total of 9 points. The player with the best score (lowest) on the hole wins 5 points, the player with the second best score earns 3 points and the player with the worst gets 1 point. In the event of a tie for the best score on a hole the two best players will each get 4 and the worst player gets 1 point. If everyone ties then each player gets 3 points on that hole. If there is a tie for the second best score on a hole then the player with the best score gets 5 points and the other two each get 2 points. If a player gets a birdie they will receive an additional 2 points on that hole. If a player gets an eagle, they will receive an additional 3 points on that hole.

Stableford[link]

Under the Stableford system the player gains points for the score achieved on each hole of the round or tournament (1 point for a bogey, 2 points for a par, 3 points for a birdie, 4 points for an eagle, and so on). The points achieved for each hole of the round or tournament are added together to produce the total points score. The player with the highest score wins.^[13]

Team play[link]

Junín Golf Club, in Junín, Argentina.

• Foursome: defined in Rule 29, this is played between two teams of two players each, in which each team has only one ball and players alternate playing it. For example, if players 'A' and 'B' form a team, 'A' tees off on the first hole, 'B' will play the second shot, 'A' the third, and so on until the hole is finished. On the second hole, 'B' will tee off (regardless who played the last putt on the first hole), then 'A' plays the second shot, and so on. Foursomes can be played as match play or stroke play.^[26]
• Fourball: defined in Rules 30 and 31, this is also played between two teams of two players each, but every player plays their own ball and for each team, the lower score on each hole is counted. Fourballs can be played as match play or stroke play.^[27]

Unofficial team variations[link]

• Scramble: also known as ambrose or best-shot; each player in a team tees off on each hole, and the players decide which shot was best. Every player then plays their second shot from within a clublength of where the best shot has come to rest, and the procedure is repeated until the hole is finished. In a champagne scramble, each player in a team tees off on each hole. The best drive is used and all players play their own ball from this spot.^[28]
• Better ball or best-ball: like fourball, each player plays the hole as normal, but the lowest score of all the players on the team counts as the team's score. ^[29]
• Greensome: also called modified alternate shot; both players tee off, and then pick the best shot as in a scramble. The player who did not shoot the best first shot plays the second shot. The play then alternates as in a foursome.^[30] A variant of greensome is sometimes played where the opposing team chooses which of their opponent's tee shots the opponents should use. The player who did not shoot the chosen first shot plays the second shot. Play then continues as a greensome.
• Shotgun start: mainly used for tournament play, this consists of groups starting on different holes, allowing for all players to start and end their round at the same time. All 18 holes are still played, but a player or foursome may, for instance, start on hole 5, play through to the 18th hole, then continue with hole 1 and end on hole 4.

Handicap systems[link]

A handicap is a numerical measure of an amateur golfer's ability to play golf over the course of 18 holes. Handicaps can be applied either for stroke play or match play competition. In either competition, a handicap generally represents the number of strokes above par that a player will achieve on an above-average day (i.e., when playing well).

In stroke play competition, the competitor's handicap is subtracted from their total gross score at the end of the round, to calculate a net score against which standings are calculated. In match play competition, handicap strokes are assigned on a hole-by-hole basis, according to the handicap rating of each hole (which is provided by the course). The hardest holes on the course receive the most handicap strokes, with the easiest holes receiving the least handicap strokes.

Calculating a handicap is often complicated, but essentially it is representative of the average over par of a number of a player's previous above-average rounds, adjusted for course difficulty. Legislation regarding the calculation of handicaps differs among countries. For example, handicap rules may include the difficulty of the course the golfer is playing on by taking into consideration factors such as the number of bunkers, the length of the course, the difficulty and slopes of the greens, the width of the fairways, and so on.

Handicap systems are not used in professional golf. Professional golfers often score several strokes below par for a round and thus have a calculated handicap of 0 or less, meaning that their handicap results in the addition of strokes to their round score. Someone with a handicap of 0 or less is often called a 'scratch golfer'.

Popularity[link]

Part of a golf course in western India.

In 2005, Golf Digest calculated that the countries with most golf courses per capita, starting with the best endowed were: Scotland, New Zealand, Australia, Republic of Ireland, Northern Ireland, Canada, Wales, United States, Sweden, and England (countries with fewer than 500,000 people were excluded). Apart from Sweden, all of these countries have English as the majority language, but the number of courses in new territories is increasing rapidly.

The most notable example of this phenomenon is the expansion of golf in China. The first golf course in China opened in 1984, but by the end of 2009 there were roughly 600 in the country. For the last several years, development of new golf courses in China has been officially banned (with the exception of the island province of Hainan), but the number of courses has nonetheless tripled since 2004; the "ban" has been easily evaded with the government's tacit approval simply by not mentioning golf in any development plans.^[31]

In the United States, the number of people who play golf twenty-five times or more per year decreased from 6.9 million in 2000 to 4.6 million in 2005,^[32] according to the National Golf Foundation. The NGF reported that the number who played golf at all decreased from 30 to 26 million over the same period.^[32]

Golf courses worldwide[link]

Number of golf course by country in 2008^[33]

Professional golf[link]

The majority of professional golfers work as club or teaching professionals ('pros'), and only compete in local competitions. A small elite of professional golfers are 'tournament pros' who compete full-time on international 'tours'. Many club and teaching professionals working in the golf industry start as caddies or with a general interest in the game, finding employment at golf courses and eventually moving on to certifications in their chosen profession. These programs include independent institutions and universities, and those that eventually lead to a Class A golf professional certification.

Instruction[link]

Indoor putting green for practice and instruction

Golf instruction involves the teaching and learning of the game of golf. Proficiency in teaching golf instruction requires not only technical and physical ability, but also knowledge of the rules and etiquette of the game. In some countries, golf instruction is best performed by teachers certified by the Professional Golfers Association. Some top instructors who work with professional golfers have become quite well known in their own right. Instructors use a combination of physical conditioning, mental visualization, classroom sessions, club fitting, driving range instruction, on-course play under real conditions, and review of videotaped swings in slow motion to teach golf.

Golf tours[link]

There are at least twenty professional golf tours, each run by a PGA or an independent tour organization, which is responsible for arranging events, finding sponsors, and regulating the tour. Typically a tour has "members" who are entitled to compete in most of its events, and also invites non-members to compete in some of them. Gaining membership of an elite tour is highly competitive, and most professional golfers never achieve it.

Perhaps the most widely known tour is the PGA Tour, which tends to attract the strongest fields, outside the four Majors and the four World Golf Championships events. This is due mostly to the fact that most PGA Tour events have a first prize of at least US$800,000. The European Tour, which attracts a substantial number of top golfers from outside North America, ranks second to the PGA Tour in worldwide prestige. Some top professionals from outside North America play enough tournaments to maintain membership on both the PGA Tour and European Tour.

The other leading men's tours include the Japan Golf Tour, the Asian Tour (Asia outside Japan), the PGA Tour of Australasia, and the Sunshine Tour (for southern Africa, primarily South Africa). The Japan, Australasian, Sunshine, PGA, and European Tours are the charter members of the trade body of the world's main tours, the International Federation of PGA Tours, founded in 1996. The Asian Tour became a full member in 1999. The Canadian Tour became an associate member of the Federation in 2000, and the Tour de las Américas (Latin America) became an associate member of the Federation in 2007. The Federation underwent a major expansion in 2009 which saw eleven new tours become full members – the Canadian Tour, Tour de las Américas, China Golf Association, the Korea Professional Golfers' Association, Professional Golf Tour of India, and the operators of all six major women's tours worldwide. The OneAsia Tour, founded in 2009, is not a member of the Federation, but was founded as a joint venture of the Australasia, China, Japan, and Korean tours. All of the men's tours that are Federation members, except the China and India tours, offer points in the Official World Golf Ranking (OWGR) to players who place sufficiently high in their events. The OneAsia Tour also offers ranking points.

Golf is unique in having lucrative competition for older players. There are several senior tours for men aged fifty and over, arguably the best known of which is the U.S.-based Champions Tour.

There are six principal tours for women, each based in a different country or continent. The most prestigious of these is the United States based LPGA Tour. All of the principal tours offer points in the Women's World Golf Rankings for high finishers in their events.

All of the leading professional tours for under-50 players have an official developmental tour, in which the leading players at the end of the season will earn a tour card on the main tour for the following season. Examples include the Nationwide Tour, which feeds to the PGA Tour, and the Challenge Tour, which is the developmental tour of the European Tour. The Nationwide and Challenge Tours also offer OWGR points.

Men's major championships[link]

Lee Westwood pictured making a bunker shot at the 2008 Open

The major championships are the four most prestigious men's tournaments of the year. In chronological order they are: The Masters, the U.S. Open, The Open Championship (referred to in North America as the British Open) and the PGA Championship.^[34]

The fields for these events include the top several dozen golfers from all over the world. The Masters has been played at Augusta National Golf Club in Augusta, Georgia, since its inception in 1934. It is the only major championship that is played at the same course each year.^[35] The U.S. Open and PGA Championship are played at courses around the United States, while the Open Championship is played at courses around the United Kingdom.^[36][37][38]

Prior to the advent of the PGA Championship and The Masters, the four Majors were the U.S. Open, the U.S. Amateur, the Open Championship, and the British Amateur.

Women's major championships[link]

Lorena Ochoa; the recently retired number one female golfer, pictured here in 2007.

Women's golf does not have a globally agreed set of majors. The list of majors recognised by the dominant women's tour, the LPGA Tour in the U.S., has changed several times over the years, with the last change in 2001. Like the PGA Tour, the (U.S.) LPGA^[39] has four majors: the Kraft Nabisco Championship, the LPGA Championship, the U.S. Women's Open and the Women's British Open. Only the last of these is also recognised by the Ladies European Tour. The other event that it recognises as a major is the Evian Masters, which is currently sanctioned by the LPGA only as a regular tour event but will become a major on that tour in 2013. However, the significance of this is limited, as the LPGA is far more dominant in women's golf than the PGA Tour is in mainstream men's golf. For example, the BBC has been known to use the U.S. definition of "women's majors" without qualifying it. Also, the Ladies' Golf Union, the governing body for women's golf in the UK and Republic of Ireland, has stated on its official website that the Women's British Open is "the only Women's Major to be played outside the U.S."^[40] For many years, the Ladies European Tour tacitly acknowledged the dominance of the LPGA Tour by not scheduling any of its own events to conflict with the three LPGA majors played in the U.S., but that changed beginning in 2008, when the LET scheduled an event opposite the LPGA Championship. The second-richest women's tour, the LPGA of Japan Tour, does not recognise any of the U.S. LPGA or European majors as it has its own set of majors (historically three, since 2008 four). However, these events attract little notice outside Japan.

Senior major championships[link]

Senior (aged fifty and over) men's golf does not have a globally agreed set of majors. The list of senior majors on the U.S.-based Champions Tour has changed over the years, but always by expansion. The Champions Tour now recognises five majors: the Senior PGA Championship, the United States Senior Open, the Senior British Open Championship, The Tradition and the Senior Players Championship.

Of the five events, the Senior PGA is by far the oldest, having been founded in 1937. The other events all date from the 1980s, when senior golf became a commercial success as the first golf stars of the television era, such as Arnold Palmer and Gary Player, reached the relevant age. The Senior British Open was not recognised as a major by the Champions Tour until 2003. The European Seniors Tour recognises only the Senior PGA and the two Senior Opens as majors. However, the Champions Tour is arguably more dominant in global senior golf than the U.S. LPGA is in global women's golf.

Other events[link]

• Golf at the Asian Games
• Golf at the Summer Olympics

See also[link]

Golf portal

References[link]