Fast bowling

Fast bowling, sometimes known as pace bowling, is one of the two main approaches to bowling in the sport of cricket. The other is spin bowling. Practitioners are usually known as fast bowlers, fastmen, pace bowlers, or de, although sometimes the label used refers to the specific fast bowling technique the bowler prefers, such as swing bowler or seam bowler.

The main aim of fast bowling is to bowl the hard cricket ball at high speed and to induce it to bounce off the pitch in an erratic fashion or move sideways through the air, factors which make it difficult for the batsman to hit the ball cleanly. A typical fast delivery has a speed in the range of 136 to 150 km/h (85 to 95 mph). The fastest delivery officially recorded was clocked at 161.39 km/h (100.3 mph) and was bowled by Shoaib Akhtar of Pakistan during a match against England in the 2003 World Cup. The batsman facing the delivery was Nick Knight, who guided it into the leg side.

In most cricketing countries, fast bowlers are considered to be the mainstay of a team's bowling attack, with slower bowlers in support roles. In the subcontinent, especially Bangladesh and Sri Lanka and now increasingly Pakistan as well, the reverse is often true, with fast bowlers serving mainly to soften the ball up for the spinners. This is largely due to the condition of the pitches used in those countries which gives more help to spinners than to fast bowlers, but at international level it is also a reflection of the outstanding skills of their spinners compared to their pace bowlers.

Categorisation of fast bowling
It is possible for a bowler to concentrate solely on speed, especially when young, but as fast bowlers mature they pick up new skills and tend to rely more on swing bowling or seam bowling techniques. Most fast bowlers will specialise in one of these two areas and will sometimes be categorised as swing or seam bowler. However, this classification is not satisfactory because the categories are not mutually exclusive and a skilled bowler will usually bowl a mixture of fast, swinging, seaming and also cutting balls, even if he or she prefers one style to the others.

Instead, it is more common to subdivide fast bowlers according to the average speed of their deliveries, as follows.

There is a degree of subjectivity in the usage of these terms; for example, Cricinfo uses the terms "fast-medium" and "medium-fast" interchangeably. The fastest bowlers are said to bowl at express pace. For comparison, most spin bowlers in professional cricket bowl at average speeds of 45 to 55 mph (70 to 90 km/h). The ability of some bowlers to deliver a variation ball, faster or slower than their standard, can cause some confusion as they could appear to put them in different categories, for example, Brett Lee bowls his stock ball at around 145 km/h, making him a fast bowler, although he will occasionally bowl a slower ball at around 115 km/h. Conversely, Shahid Afridi, a spin-bowler, has a quicker ball which can reach 134 km/h. However these are rarely taken into account in determining what category a bowler fits in because these deliveries are variations, intended to surprise the batsman, not the standard pace of a bowler.

The slower the fast bowler, the more they have to rely on the variation techniques listed below to get wickets, though fast and to a lesser extent fast-medium bowlers can often get batsmen out through sheer speed and aggression. In practice, very few specialist bowlers fall into the medium-fast and medium categories - bowlers who bowl at this speed are mostly batsmen who can bowl a few overs on occasion. These bowlers are known as medium pacers. The medium-slow and slow-medium categories are mostly occupied by spin bowlers, since a delivery bowled at these speeds with a fast bowling technique, rather than spin, would simply be too easy to hit. Although spinners are sometimes colloquially referred to as "slow bowlers", very few players in professional cricket bowl in the actual "slow" category (below 40 mph).

Grip
The first thing a fast bowler needs to do is to grip the ball correctly. The basic fast bowling grip to achieve maximum speed is to hold the ball with the seam upright and to place the index and middle fingers close together at the top of the seam with the thumb gripping the ball at the bottom of the seam. The image to the right shows the correct grip. The first two fingers and the thumb should hold the ball forward of the rest of the hand, and the other two fingers should be tucked into the palm. The ball is held quite loosely so that it leaves the hand easily. Other grips are possible, and result in different balls - see swing and seam bowling below. The bowler usually holds their other hand over the hand gripping the ball until the latest possible moment so that the batsman cannot see what type of grip he or she is employing and prepare accordingly.

Run-up
A fast bowler needs to take a longer run-up toward the wicket than a spinner, due to the need to generate the momentum and rhythm required to bowl a fast delivery. Fast bowlers will measure their preferred run up in strides and mark the distance from the wicket. It is important for the bowler to know exactly how long his or her run-up is because it needs to terminate at the popping crease. If the bowler steps over this, he or she will have bowled a no ball.A no ball means the bowler will have to bowl again.

Action
At the end of the run-up the bowler will bring his or her lead foot down on the pitch with the knee as straight as possible. This aids in generating speed but can be dangerous due to the pressure placed on the joint by this action. Knee injuries are not uncommon amongst fast bowlers: for example the English pace bowler David Lawrence was sidelined for many months after splitting his kneecap in two. The pressure on the leading foot is such that some fast bowlers cut the front off their shoes to stop their toes from being injured as they are repeatedly pressed against the inside of the shoe. The bowler will then bring their bowling arm up over their head and release the ball at the height appropriate to where they want the ball to pitch. Again, the arm must be straight although this is a stipulation of the laws of cricket rather than an aid to speed. Bending the elbow and "chucking" the ball would make it too easy for the bowler to aim accurately at the batsman's wicket and get them out. Fast bowlers tend to have an action which leaves them either side-on or chest-on at the end of the run up. A chest on bowler has chest and hips aligned towards the batsman at the instant of back foot contact, while a side on bowler has chest and hips aligned at ninety degrees to the batsman at the instant of back foot contact. West Indian bowler Malcolm Marshall was a classic example of a chest on bowler, while Australian pace bowler Dennis Lillee used a side on technique to great effect.

While a bowler's action does not affect the speed at which they bowl, it can limit the style of balls that they can bowl. Although not hard and fast rules, side on bowlers generally bowl outswingers, and front on bowlers generally bowl inswingers.

A variant on the fast bowler's action is the sling (sometimes referred to as the slingshot or javelin), where the bowler begins his delivery with his or her arm fully extended behind their back. The slinging action generates extra speed, but sacrifices control. The most famous exponent of the slinging action is Jeff Thomson, who bowled at extraordinary pace off a short run up. Current internationals who employ a slinging action include Fidel Edwards, Shaun Tait, Lasith Malinga and Mitchell Johnson.

Follow through
After the ball has been released, the bowler "follows through" at the end of his or her action. This involves veering to the side so as not to tread on the pitch and taking a few more strides to slow down. Striding on to the pitch at the end of a delivery can damage the surface resulting in rough patches which spin bowlers can exploit to get extra turn on the ball; doing so is illegal according to the laws of the game. Bowlers who persistently run onto the pitch can be warned, with three warnings disqualifying a bowler from bowling again during the innings.

Line and length
An effective fast bowler needs to be able to hold a consistent line and length, or in common terms, to be accurate. In this context, line refers to the path of the ball towards the batsman, in the horizontal dimension running from the off to the leg side, while length describes the distance the ball travels toward the batsman before bouncing. Length is generally seen as the more important of the two for a fast bowler. The faster the bowler, the harder it is to achieve consistent line and length but sheer speed can make up for the shortfall. Fast bowlers who also manage to be accurate can be devastatingly effective, for example the likes of Australian pace bowler Glenn McGrath and South African pace bowler Shaun Pollock.

Line
In modern cricket, the line usually aimed for by fast bowlers is the so-called corridor of uncertainty, the area just outside the batsman's off stump. It is difficult for the batsman to tell whether or not such a ball is likely to strike their wicket, and thus to know whether to attack, defend or leave the ball. This technique was historically known as off theory (contrast leg theory), but it is now so routine that it is rarely given a name at all. Of course, variation in line is also important and deliveries aimed at the leg stump can also serve a purpose.

Precise mastery of the line of the ball is best utilised when a batsman is known to have a weakness hitting a particular shot, because a bowler with an effective line can place the ball in the weak spot time after time. Failing to overcome a persistent inability to hit balls on a certain line has been enough to end the careers of innumerable batsmen once they had been found out by skilled line bowlers.

Length
A good length ball is one that arrives at the batsman at around waist height. There is no fixed distance to a good length, or indeed any other length of ball in cricket since the distance required will vary with the speed of the ball, the state of the pitch and the height of the bowler and batsman. It should be noted that bowling a "good length" in this sense is not always appropriate - in some situations, on some pitches and against some batsmen other lengths will be more effective. The diagram to the right should help explain what the different lengths mean.

A ball which bounces a little way before the good length and rises to the batsman's abdomen is said to be short pitched or described as a long hop and is easier for a batsman to hit as he will have had more time to see if the height or line of the ball has deviated after bouncing. A short-pitched ball is also at a more suitable height for the batsman to play an attacking pull shot. A ball which bounces way before the good length and reaches shoulder or head height is a bouncer and can be an effective delivery. Any ball which is short enough to bounce over the batsman's head is usually called wide by the Umpire. Bowling short pitched or wide balls is a bad idea as they are relatively easy for the batsman to defend or attack.

At the other end of the scale, balls which bounce slightly closer to the batsman than the good length are said to be full pitched or overpitched or described as a half volley. These are easier for the batsman to play than the good length because they don't have time to move much after bouncing off the seam. Closer still to the batsman's feet is the yorker, a very effective length if bowled correctly. If the ball fails to bounce at all before reaching the batsman it is labelled a full toss. It is very easy for a batsman to play such a delivery as it will not have deviated at all from bouncing off the pitch.

It is because the three effective lengths (good length, bouncer and yorker) are all interspersed by lengths which are easy for the batsman to hit that control of length is an important discipline for a fast bowler. Spin bowlers on the other hand are almost always aiming for the good length but need a much finer control of flight and line to be effective. A fast bowler tries to be physically fit throughout his cricket career, which may span more than a decade. Needless to say that is tough to do and needs a lot of discipline and luck.

Strike bowling
Strike bowling is the term usually applied to bowlers that are used mainly to get a batsman out at the possible expense of runs if the wicket-taking is unsuccessful. For fast bowlers, this can be achieved through sheer speed and aggression, rather than trying to make the ball move through the air or off the pitch. More commonly however, aggressive bowling techniques can be combined with swing bowling and seam bowling techniques to create nigh-on unplayable balls in the hands of a bowler of any speed. The inswinging yorker is seen as particularly deadly.

Bouncer
A bouncer is a ball which is aimed to pitch in the first half of the pitch, meaning it has had time to rise sharply to chest or head height by the time it reaches the batsman. This causes two problems for the batsman who receives the ball. If he or she attempts to play it, their bat will be at eye-level making it difficult for them to watch the ball onto the bat and time their shot correctly. If he or she leaves or misses the ball, it may strike him or her a painful blow on the head or chest and occasionally result in injury. For this reason, bowling spells containing many bouncers are said to be intimidatory bowling.

The usual response to a bouncer is for the batsman simply to duck underneath it, but this requires fast reflexes and a strong nerve and the batsman is sometimes hit in any case. The natural reflex is to attempt to defend one's head with a straight bat but this should be suppressed if possible as the likely result of this will be that the ball flies off the bat at an uncontrolled angle making for an easy catch. Most batsman have panicked and lost their wickets in this fashion several times in their career after prolonged spells of bouncers.

Physically powerful batsmen often attempt to strike the ball on the rise, even though this obstructs their vision of the ball since it is not uncommon that their sheer brute force combined with the speed of the ball will cause it to fly to the boundary. This possibility, combined with the difficulty that the wicketkeeper will have trying to stop a high ball means that bouncers can be expensive in terms of runs against skilled batsmen.

Slower ball


A slower ball is a ball which is delivered exactly like a usual pace delivery in terms of action and run-up but where the grip is changed slightly in order to slow the ball down. This deceives the batsman, who will likely attempt to play the ball as though it were at full speed, causing him or her to mistime their shot. The result is usually that the ball strikes lower down the bat resulting in it leaving the bat at a slower speed (a cricket bat has a middle - hitting the ball at this point will result in the maximum possible energy being transferred to the ball; as the ball is hit away from the middle so the energy transferred, and hence the speed, will decrease). Also, the bat will generally have travelled further when it hits the ball and be in the upward part of its arc, causing the ball to leave the bat at a steeper angle. The combination of these can be a slow-moving, looping catch which is relatively easy to catch. In an extreme case, the batsman will play the shot so early as to completely play over the ball, and be clean-bowled.

One of a number of different grips is illustrated to the right. Essentially the only difference is that the middle and index fingers are split and come down on each side of the seam. This causes more drag on the ball as it leaves the hand, slowing down the delivery. Slower balls are also bowled by using the off break grip and finger action used by off spinners. A slower delivery may also be achieved - less commonly - by using a leg spin grip and wrist action or by supporting the upper aspect of the ball with only one finger or with the knuckles.

The slower ball is particularly effective against a batsman seeking to score quickly. Consequently, its prominence has increased with the development of one-day cricket, and particularly at the end of an innings where batsman will attack with abandon.

A more experienced batsman will be able to adjust his/her shot mid-stroke, momentarily pausing so as to middle the ball when it is hit.

Another version of the slower ball also known as the SLOB, is released with the top fingers only. Aimed as a "beamer", the method of delivery causes the ball to drop dramatically in flight and arrive at a yorker length. This was most famously used by Chris Cairns to Chris Read causing him to duck into a full length ball which sent stumps flying.

Yorker
A yorker is a ball which bounces off the pitch right in front of (or is aimed at the toes of) the batsman's feet, an area known as the block hole. Because of the usual stance of the batsman and the regulation length of the cricket bat the bat is not usually held near the ground while the batsman prepares to strike the ball, so playing a yorker requires the batsman to alter the height of his or her bat very quickly after detecting a yorker has been bowled. This is difficult, and the yorker can often squeeze through the gap and break the wicket. Successfully playing this type of delivery is also known as digging out a yorker.

Bowling a yorker requires pinpoint accuracy since bowling it slightly too long will result in a full toss or full pitched delivery which is easy for the batsman to play because the ball has not deviated by bouncing off the pitch. It also has most of its value as a surprise ball. For these two reasons, yorkers are not common deliveries in most circumstances.

In the latter stages of an innings in one day cricket, batters seek to attack every ball bowled. In such circumstances, the yorker is a particularly effective delivery, both in taking wickets and preventing boundaries from being hit. Therefore, the yorker is very frequently bowled in these circumstances, and bowlers who can bowl yorkers accurately are prized in this form of cricket.

Seam bowling
Seam bowling is the act of using the seam of the ball to cause the ball to bounce in an unpredictable fashion when it hits the pitch. A good batsman will be able to predict where a ball is going to bounce and from that work out what height the ball will be when it reaches him or her. By generating variations in bounce, the bowler can make it more likely the batsman will make a mistake in his assessment of the ball and give away their wicket.

Seam deliveries can be bowled at any pace, but most specialist seamers bowl at medium, medium-fast or fast-medium pace. The basic technique of seam bowling is to employ the normal fast bowling or slower ball grip and to try to ensure that the seam remains upright until the ball hits the pitch. If the seam is upright and the ball is spinning around its horizontal axis, there is no appreciable Magnus effect and the ball will not move in the air. The seam of the ball is raised and will cause variations in bounce and movement if it is the first part of the ball to hit the pitch.

Seam bowlers can get a lot of help from certain types of pitches. Hard pitches that have a cracked or ridged surface are best for seam bowling since the hardness makes it easier to bounce the ball without losing speed while the uneven surface adds to the unpredictability of the bounce when the ball hits the pitch. This is known as variable bounce. On rare occasions a pitch which is extremely hard and uneven will be declared as too dangerous to play on since the batsman cannot predict the ball at all and they are likely to be hit on the body repeatedly as a result. Green pitches can also assist the seam bowler since the tiny tufts of grass represent an uneven surface although this is a mixed blessing since the green surface also slows the ball slightly. It is difficult for a seam bowler to be effective on a very flat and even-surfaced pitch (known as a flat track in cricket vernacular) and seamers usually resort to aggressive bowling tactics and/or bowling cutters on such surfaces.

Cutters

 * Main articles: Leg cutter, Off cutter

A cutter is the term used to describe a fast ball which is spinning, that is, a delivery that is rotating around the opposite axis to the seam instead of keeping the seam straight. While this rotation is nowhere near as much as that achieved by a spin bowler, the small variations it can produce are still enough to discomfort a batsman due to the speed of the ball. Cutters can be an effective way for a seam bowler to get the ball to move if he or she is not receiving much assistance from the pitch.

A ball rotating around the seam will move either right or left when it hits the pitch, depending on which way the ball is spinning. A ball bouncing to the right is said to be an off cutter as it is travelling from off stump to leg stump for a right-handed batsman. Conversely, a ball which bounces to the left is a leg cutter, travelling from leg to off stump for a right-handed batsman. Cutters are usually aimed so that they hit the pitch just outside the batsman's off stump and move away from the wicket. This will cause the ball to catch the outside edge of the bat instead of the middle and fly up to be caught in the slips.

To bowl a cutter, the bowler employs a different grip. The two grips are shown to the right, with the uppermost one producing an leg cutter while the lower one shows the grip required for an off cutter. As well as changing the grip, the bowler must pull his or her fingers down the appropriate side of the ball as it leaves their hand in order to impart the required spin. The action of bowling a cutter also increases drag on the ball as it leaves the hand, causing the ball to slow in the same way as a slower ball and this can also help to confuse the batsman.

Swing bowling
Swing bowlers cause the ball to move laterally through the air, rather than off the pitch like seam bowlers. Normal or conventional swing bowling is encouraged by the raised seam of the ball, and conventional swing is usually greatest when the ball is new and therefore has a pronounced seam. As the ball gets older, the wear makes swing more difficult to achieve, but this can be countered if the fielding team systematically polishes one side of the ball while allowing the other to become rough. When the ball has been polished highly on one side and not on the other and if the ball is bowled very fast (over 85 miles per hour), it produces a reverse swing such that the ball swings in the opposite direction as in conventional swing. Contrary to popular opinion, this swing is not produced by air flowing faster over the smooth or "shiny" side as compared to the rough side.

Swing is produced due to a net force acting on the ball from one side; that is, the side with the more turbulent boundary layer. For conventional swing bowling, the raised seam and the direction in which it is pointed governs the direction of swing. Due to the angled seam of the ball, air flowing over the seam produces turbulence on the side that the seam is angled toward. This causes the boundary layer to separate from the surface of the ball later (farther toward the rear of the ball) than the other side where it separates earlier (farther forward on the surface). As explained by Bernoulli's principle, there is a net pressure differential due to the greater pressure on the side with the more intact boundary layer. The resulting net force acts so as to move or swing the ball in the direction of the angled seam. Conventional swing bowling is delivered with the seam angled such that the smooth or polished side of the ball faces forward to move the ball in the direction of the seam i.e. toward the rough side.

A swinging ball is classed as either an outswinger, which moves away from the batsman, or an inswinger, which moves in toward the batsman. In most cases the outswinger is seen as the more dangerous ball because, if the batsman fails to recognise it, it will catch the outside edge of the bat instead of the middle and fly up to be caught in the slips. Inswingers have their place too, especially combined with the yorker as the inswinger can catch the inside edge and break the wicket, or hit the batter on the pad rather than the bat, resulting in a possible LBW decision.

Swing bowling can also be roughly categorised as early swing or late swing, corresponding to when in the trajectory the ball will change direction - the later the ball swings, the less chance the batter has of adjusting his/her shot to account for the swing.

Swing balls are bowled with the same grip and technique as fast balls although the seam is usually angled slightly rather than straight, and the slower ball grip may be used. For an outswinger the shiny side of the ball is nearest the batsman and the seam is angled away from him while for an inswinger, the rough side needs to be nearest the batsman and the seam angled toward them. It is difficult to achieve swing with a cutter grip since the ball will spin in flight, varying the orientation of the shiny and rough surfaces as it moves through the air. Many players, commentators on the game, and fans agree that swing is easier to achieve in humid or overcast conditions, and also that the red ball used in Test cricket swings more than the white ball used in the one-day game.

Reverse swing
Reverse swing is a phenomenon which causes the ball to swing in the opposite direction to that usually produced by the orientation of the shiny and rough sides of the ball. When the ball is reverse swinging, the ball will swing towards the shiny side. Balls which reverse swing move much later and much more sharply than those swinging conventionally, both factors increasing the difficulty the batsman will have in trying to hit the ball.

Reverse swing is much more dependent on conditions than normal swing, and so it is nearly impossible to achieve consistently. Reverse swing does not usually happen until the ball is around 45 overs old, and requires the weather to be hot and dry.

In reverse swing, the rough side is placed forward. The seam is angled in the same way as in conventional swing (10-20 degrees to one side) BUT the boundary layer on both sides is turbulent. The net effect of the seam and rough side is that the ball actually swings in the direction opposite to where the seam is pointing to. Good reverse swing bowling requires the bowler to deliver the ball at a fairly high speed (80-85 miles per hour or greater), which is only achieved by a select few fast bowlers in the world.

Now, in one-day cricket the mandatory two new balls rule (which states that two new balls must be used at the start of each innings; one from each end) means that the chances of reverse swing are reduced drastically. This is because, typically, reverse swing tends to start happening at around the 33rd-35th over. With two new balls being used, the amount of wear that each ball is subject to is half as compared to usual. Reverse swing depends on one side of the ball being very worn out, and this is less likely to happen because two new balls are used, as opposed to one.

The turbulent boundary layer separating later is similar to the effect produced by dimples in a golf ball. In case of the golf ball, turbulence is produced on both sides of the ball and the net effect is a later separation of boundary layer on both sides and smaller wake in the back of the ball and a lower net drag due to pressure differential between the front and the back - this enables the golf ball to travel farther.]

Dippers

 * Main articles: Indipper, Outdipper

A dipper is a swinging ball which is deliberately bowled as a yorker or a full toss; the latter not normally being a ball that a fast bowler would choose to bowl. The indipper moves in to the right-handed batsman while the outdipper moves away.

In order to be effective, a dipper has to generate a lot of swing to make up for the variation in movement lost because the ball is not bouncing on the pitch. However, because the batsman usually expects a full toss to be an easy ball to score off, dippers have huge surprise value and can be extremely difficult to play especially if the bowler is very accurate and manages the yorker rather than a genuine full toss.Chaminda Vaas use to ball dippers.

Intimidatory bowling
Intimidatory or aggressive bowling refers to a legitimate tactic of bowling with the intent of hitting the batsman with the ball. This is somewhat restrained by some of the laws of cricket, including those which disallow excessive use of bouncers and any use of the "beamer", which is aimed directly at the head on the full. Successful intimidatory bowling usually employs a mixture of bouncers and short-pitched deliveries aimed at the batsman's head, chest, and rib cage. The intention is to disrupt a batsman's focus, and ultimately induce a mistake that leads to the loss of the batsman's wicket. Often the eventual wicket will not fall to a bouncer or short-pitched ball, but instead to a more standard delivery that the batsman is no longer expecting, or is rendered temporarily unable to play in his usual way (by fear, pain, surprise, or some combination of the three).

One classic approach is to deliver several short balls into the batsman's chest, forcing the batsman onto the back foot to defend with a high bat, and then fire in a fast yorker, aimed at the base of the stumps. If the batsman is expecting to play a high back foot defensive, the time it takes to shift their weight to play the ball at their feet may just be enough for the delivery to surprise the batsman and cause him or her to panic, and thus cause the loss of their wicket.

A fast bowler can also employ intimidatory tactics to anger (or frustrate) a batsman into playing a rash shot, by directing the ball to strike the batsman. Intimidatory bowling plays a part in every fast bowlers attack to varying degrees, and even the best batsmen sometimes sustain serious injuries that can force them off the field and out of the game. In almost all instances verbal 'sledging' accompanies the attack.

Excessive use of intimidatory tactics by elite fast bowlers is considered unsportsmanlike, and is shunned by many teams and players. One instance of excessive use was the Bodyline series, where the English Cricket Captain at the time (1932-1933), Douglas Jardine, employed a tactic to restrain the skills of the Australian cricket team, and their star player, Donald Bradman. The tactic was to bowl, very fast and very short, at the batsman's body. After the Bodyline series, as it became known, several laws of cricket were altered to prevent such a tactic being used again, such as a restriction on the number of fielders that can occupy the rear leg-side quadrant of the cricket to two (excluding the wicketkeeper).

Tactics
Because nearly all cricket teams will contain several fast bowlers of differing speeds and styles, the tactics of fast bowling depends not only on changing the field placements but on changing the bowler and the types and sequences of deliveries bowled as well. The precise tactics will be determined by many factors including the state of the game, the state of the pitch, the weather and the relative energy and skill levels of the various players available to bowl.

Fast bowling requires a great deal of energy and most fast bowlers can be expected to bowl a spell of 4-6 overs in a row before requiring a rest. Depending on conditions, they may be required by the team to bowl a longer spell although this usually results in drop in effectiveness toward the end of the spell as the bowler tires. Choosing which balls to bowl as part of a spell and what order to bowl them in is a tactical discipline all of its own.

Deployment of bowlers
Most sides contain a mixture of fast bowlers who specialise in aggressive and/or seam techniques and those who specialise in swing. When the ball is new it usually swings very little but it will generate a lot of speed, bounce and variation off the seam (because the seam on a new ball stands out more than that on an old ball). So seam bowlers are usually chosen to bowl with the new ball either at the start of an innings or when a new ball has been taken, an option the fielding side has once a ball is 80 overs old. In contrast, swing bowlers are more effective once the ball has started to wear and reverse swing requires a well worn ball. Reverse swing bowlers can continue to extract large amounts of movement from balls well over 80 overs old.

Two seam bowlers are usually expected to bowl in tandem for the first 10 or so overs, after which time the ball may begin to swing and one or both of them is substituted for a swing bowler or a spin bowler. This is why most sides opt to include at least two seam bowlers who are known as opening bowlers. Seam bowling usually becomes very ineffective with older balls and is virtually useless after 60 overs or so and as a result the bowling places in the side are filled with swing or spin bowlers.

Deployment of fielders
Fielding for a fast bowler is usually aggressive, that is to say that it is set up for the purpose of getting a wicket rather than preventing the flow of runs. On occasion, particularly when the fielding team is batting last and is chasing a total, a defensive field is required. As a general rule it is difficult to bowl defensive fast bowling - that task is better suited to spin bowlers.

The various techniques of fast bowling lend themselves to three ways of getting the batsman out. They may be bowled or caught LBW either by speed, the yorker or by seam or swing causing the ball to move in toward them, in which case placement of fielders is irrelevant. Swing or seam may be employed to move the ball away from the batsman in which case the ball will strike the outside edge of the bat and may be caught in the slips. A badly-played bouncer will either fly off the outside edge as above or may result in a mistimed shot that can be caught near the boundary.

It follows that the most effective field placements for aggressive fast bowling are to pack the outfield and the slips cordon and gully since these are the positions in which the batsman is most likely to be caught. Placing fielders in the outfield has the additional benefit of limiting the number of places where a batsman can score a boundary. Other close fielding positions such as silly mid on/off and the various midwicket positions are generally redundant.

In contrast, a defensive field for fast bowling will pack the positions such as gully, point and cover in a full circle round the batsman. One or two slips and one or two outfielders will remain in case of a catch. Because batsmen usually try and play shots down on to the ground rather than risking being caught this field can stop most boundaries while remaining close enough to the pitch to attempt to run out the batsmen if they attempt a single. Defensive fast bowling is difficult because a skilled batsman set this type of field will simply trust his or her technique and score from boundaries that they hit over the midwicket ring and away from any outfielders present.

Bowling an over
The primary goal of any bowler is to take the wicket of the batsman. The secondary goal is to prevent the batsman scoring runs. The latter is often a route to the former as a batsman deprived of runs will often become frustrated and is more likely to attempt risky shots in order to score. In addition, stopping the batsman from scoring will usually mean that the bowler gets to bowl several consecutive balls at the same batsman, giving them the opportunity to set up some kind of tactical sequence.

Counterintuitively, the best approach for a fast bowler is not to aim consistent balls at the wicket as this prompts an obvious and easy response. The batsman can simply defend his or her wicket and pick off the occasional bad ball. A far more effective approach is to create uncertainty by bowling a line and length at which the batsman is unsure as to whether they should attack, defend or leave and by mixing up the types of delivery so the batsman is never sure what type of ball is coming next. The majority of balls in a well-bowled spell will usually be swinging or seaming balls that pass at waist height, just outside the off stump and move away from the batsman because this is the area where it is most difficult for the batsman to choose the most appropriate response. Common variations and their tactical application are discussed below.

The precise balls chosen by the bowler during an over will depend on the situation of the match, the skill of the batsman and how settled the batsman is at the crease. It is common to attack batsmen who have recently come to the wicket with successive short-pitched balls or bouncers with the dual aim of getting them out and stopping them from settling into an attacking mode of play for as long as possible. Short balls are more risky against batsmen who have settled at the crease since they make easy boundaries, but most bowlers will still mix a few in during a spell, just to keep the batsman guessing.

Most batsmen prefer to play shots off either the front or back foot and this will influence the bowlers' choice of balls. It is difficult to play short balls off the front foot so bowlers will bowl more short balls at batsmen who prefer the front foot. Likewise, it is hard to play yorkers and full pitched balls off the back foot so those are the deliveries of choice against back foot players. If a bowler can successfully get a batsman playing off his or her less-favoured foot with a sequence of appropriately pitched balls he can then gain an element of surprise by suddenly throwing down the opposite kind of ball - a yorker after a succession of short balls or a bouncer after a succession of full balls. An unobservant or complacent batsman can easily be caught unawares and lose their wicket.

Another variation, especially against batsmen who have settled at the wicket and are starting to score more freely, is to switch the line of attack from the area just outside the off stump to bowling directly at leg stump. The batsman has to react to these balls as he otherwise runs a high risk of being bowled or trapped LBW but as he or she does so his or her bat moves over to the leg side, leaving the off side vulnerable. If the bowler can induce enough movement to the off side with swing or seam techniques it will often catch the outside edge of the bat offering a catch or strike the stumps directly.

It must be remembered that surprise is a big element in bowling, and bowlers will often shun these common tactical approaches in the hope of simply confusing the batsman into playing the wrong shot. For example, bowling a yorker at a new batsman who will likely be expecting bouncers or at least standard line and length balls has been the cause of many batsmen losing their wicket first ball.

Risks of injuries
The human body is not built for the work load of fast bowling. Fast bowling puts extreme pressure on the whole body, especially the feet, back and the shoulder. It puts a lot of body parts under extreme risk of injury. There's a risk of stress fractures in the ankles because of the feet landing hard on the ground at the time of delivery, back spasms and strains because of the arching movement when the ball is delivered and torn ligaments in the shoulder because of the sudden jerk that invariably occurs just before the ball is bowled. Nevertheless, it is possible for fast bowlers to follow various workout regimes suited especially for them.