The Indian cricket team sets off in the much anticipated test series in Australia this week. In fact, the first match of the series will take place at the Adelaide Oval from this Thursday. Most importantly, it will be a pink-ball encounter to start the battle of the best. The table toppers of the ICC Test Championship would need to beat the massive swing that this pink ball produces, in order to gain a positive start in this series.
The Pink Test: India v Australia, 2020
Interestingly, it is the first time when India will play a day-night test abroad. To clarify, the Indians played only one pink ball test till date, against Bangladesh at Kolkata last year. Needless to say, the Indians won that game almost unchallenged, by a margin of an innings and 46 runs. Hence, the challenge is really high in front of the touring Indian side this time.
Australia is a really tough team to beat at their home. Especially in test cricket, it is almost next to impossible. However, the Indian team made history during its last tour down under in 2018-19. Under the leadership of Virat Kohli, India beat the hosts by a margin of 2-1 in the 4-match test series on that tour, en route to their first ever test series victory in Australia. So, the baggy greens would love to avenge the past with commanding wins this time around.
Hence, the first match of the series turns out to be a minefield with access to the lethal pink ball and its characteristics of swing! But, do you ever wonder why the pink ball has this dire capability of swing?
The Extra Swing on Pink Ball
Initially, cricket in the top level was all about the red ball. Till 1971, only test cricket held the international status. The game was played in daylight only. However, with the evolution of One Day cricket, the scene changed drastically. Not only the game got restricted within a fixed number of overs, the duration of play exceeded sunset. Hence, cricket included floodlight to incorporate the sport at night with the facility of artificial lighting.
In addition, this new form of cricket brought change in the ball used too. Instead of the traditional red, white balls took its turn in the day-night form of cricket. With the immense rise in popularity of ODIs and later, the T20Is, and the fall in interest with test cricket among the public, ICC had to think of something new to revive this format. Hence in the year 2015, the first day-night test took place under floodlight at the Adelaide Oval, Australia.
That brought another superficial change with the cricket ball. A pink colored ball was seen in action at this game, for the first time in men’s international cricket. In fact, this closely fought match unleashed many mysterious habits of this fresh addition in cricket. The most interesting one was of course the extra swing that this pink ball generated.
To know why, we need to know how a cricket ball acts in the art of bowling.
The Cricket Ball
A cricket ball holds wooden cork in its spherical core wound with string. A leather coating covers this core with six rows of stitching that makes two hemispheres off the surface of the ball. These two halves and the stitch itself are the principle components behind the different styles of bowling.
- Pace Bowling: The pace bowlers use the speed of the ball to rattle the timing of the batsmen. In addition, the pacers use the bounce of the pitch to direct balls out of the comfort zone to get a batsman dismissed.
- Seam Bowling: The seam bowlers hit the stitch of the ball, also called the ‘seam’, to ground, in order to generate sideways movement on the bounce. As the seam resists the ball to act as a perfect sphere, the impact with the pitch creates random deviation on the recoil, that might unsettle the batsman.
- Spin Bowling: The spin bowlers rotate the ball off their wrist or fingers before release. The rotational motion makes the ball turn, off the bounce. The variation and surprise of this turn makes the life of the batsmen miserable in this form of bowling.
- Swing Bowling: Pace bowlers employ the technique of swing bowling to deceive the batsman with a swinging ball at a high speed. To clarify, the swing bowlers generate deviation in the path of the delivery using flow of air. It involves some careful handling of the surface of the ball to earn swing off the new ball, or the old ball, apart from suitable pitch and weather conditions.
To find out about the extra swing from the pink cricket ball, we must learn how swing bowlers spawn the art.
The Physics of Swing Bowling
The sport of cricket involves great amount of science in itself. The very special art of swing bowling is a rare skill in cricket. In fact, there are three kinds of swing bowling that involves one single physical convention to achieve different results.
In general, the flow of air against the moving ball and the position of the seam together produce the swing. Let’s think of a real life example for better understanding. For instance, when we travel in a high-speed train, the air seems to hit us in the reverse direction. In fact, the same theory works in case of swing bowling.
As a bowler releases the ball during a delivery, it travels through air to the batsman, that may or may not include a drop off the pitch in case of a legal delivery. Now, the consequent layers of air displaced by the moving ball travels in opposite direction to the ball, and collides with the ball itself. This collision divides the air flow into two halves, forcing each half of air travel across the opposite surfaces of the ball.
The difference in air pressure between these two halves create the change of direction in motion of the ball. This deviation of track of the ball is indeed termed as ‘swing’.
Next, let’s find in detail how three different types of swing bowling works in terms of science.
1. How ‘Conventional’ Swing Works
The traditional form of swing bowling works with the new ball only. In fact, the red ball in test cricket supports it for longer period compared to the white ball in limited overs. On the other hand, the pink ball brings in real nightmare for the batting side as it contains swing for even longer duration than the red one.
Before coming to the reason behind such contrast of swing facilities in terms of color of the ball, let’s find out how conventional swing works.
A new ball bowler holds the seam of the ball inclined against the grip of the fingers. The ball swings in the way of the inclination when it is released. In other words, the ball moves towards the left if the seam is held facing left, and vice versa.
To clarify how it works, let’s remember the fact that air splits up opposite to the path of the ball. As the seam of ball travels inclined on one end, air acts differently over the two surfaces. The half of the air traveling across the side with the seam facing, turns turbulent over friction with the rough seam. On the other side, the air flows smoothly across the shiny surface.
By the laws of physics, turbulent air has less pressure than its smoother counterpart. Also, air intends to move from low pressure area towards high pressure area, as per Bernoulli principle. Hence, the smooth air on the shiny surface of the ball exerts a greater pressure than the air moving across the seam. As a result, the ball moves towards the face of the seam due to this excess pressure.
Hence, a new ball bowler generates inswing with the seam held inward and outswing with it held outward, for a right handed batsman.
The conventional swing is the traditional mode of swing achieved in cricket across years. In fact, the best top order batsmen across centuries earned their names for being able to interpret the swing of the new ball. As explained, the grip of the bowler pretty much determines the way of swing for a given delivery. Hence, a batsman attempts to look into the grip of the bowler, in order to determine the best shot in response. However, a few bowlers often hide their grip till the last moment possible before release, to avert this interpretation. Zaheer Khan from India could be the perfect example in this context.
The conventional swing works on a new ball only. Once the ball gets old after the first 15 overs, it is not possible to generate this form of swing. Instead, old ball specialists use the ‘contrast’ mode of swing in their skill set.
With the new rules in ODI cricket that allows the use of two new white balls from two ends, the conventional swing is a valuable weapon for any bowling side in this format.
2. How ‘Contrast’ Swing Works
In test cricket, the opening batsman has a duty to see off the new ball. In other words, the top order batsmen defends or leaves the deliveries with conventional swing from the new ball until it gets old. This is how they create relief for the middle order who are more comfortable against the old, weary ball.
But, that did not restrict the bowlers to find ways to trigger swing with the older ball. Instead, the concept of contrast swing comes into play at this moment.
The ‘contrast’ mode of swing requires team effort apart from a skilled bowler for execution. It is because the surface of the ball must contain contrasting halves to generate contrast swing. To clarify, a ball must have one end shiny and the other end old, weary for this mode of swing bowling.
The bowler holds the seam right under the grips, without any inclination, unlike the techniques for conventional swing. Hence, the ball is released straight. Thereafter, the air in path of the ball makes it move towards the weary end, opposite to the shiny one. So, the direction of swing depends on whether the shiny end of the ball is held to the left or to the right. For a right handed batsman, the ball with weary end held leftward will generate outswing. On the other hand, the ball would go for inswing if the weary end is held at right.
To achieve this contrast in the shape of the ball, the fielding side employs various strategies. The fielders make sure the shiny end does not bounce during a throw, since that might minimize its shine. Also, they rub the rough side into their clothing, in order to accelerate the wearing of the other surface. Substances like Vaseline, fingernails and sandpaper got banned after being used to achieve this. Sweat and saliva could be used earlier but the latter is banned under the COVID-19 restrictions from this year.
As discussed earlier, air cuts into two halves when the cricket ball travels through it. By the same laws of fluid, the pressure on the rough side is less than that on the shiny one. This results the ball deviate towards the rough side due to the pressure gap acting on it. Hence, even the ball was bowled with a straight seam on top, the ball swings through the air instead of traveling straight.
The contrast mode of swing with the old ball is not as useful as the conventional new ball swing. In fact, spin bowlers often get priority in the middle overs as the old ball is apt to practice their skills. Also, seam bowlers and variation bowlers share the attack, with old ball specialists able to bring contrast swing.
In fact, contrast swing is tough to be produced in the shorter form of cricket. Nowadays, even 50-over cricket is played with two new balls. Hence, it is really tough to achieve the prerequisite contrast in the shape of the ball, in order to try contrast swing.
However, this kind of swing can often be seen in the longer form of cricket. As a fielding team can ask for a new ball only after 80 overs in an innings, the role of contrast swing is significant in the longer format, especially in pitches outside the subcontinent.
The conventional and contrast swing were part of the game almost since its inception. However, a third mode of swing made the headlines in the late 1970s.
3. The ‘Reverse’ Swing
Reverse swing is one of the fiercest inventions in cricket. In fact, this mode of swing had its birth in Pakistan and rocked the cricketing world in the hands of pace trio Imran Khan, Wasim Akram and Waqar Younis.
This version of swing works with the old ball only. But, it works differently than the contrast swing discussed earlier. In fact, it works in the reverse way to the conventional swing.
Just like conventional swing, the bowler holds the seam of the old ball inclined under the grips of the fingers. However, the ball swings opposite to the face of the seam in this mode of swing. Hence, it is called as the ‘reverse’ swing.
So, an inward seam would force the ball move for an outswing, and vice versa, for a right handed batsman. The trajectory of the ball indeed forms the shape of English alphabet ‘S’ in reverse swing.
At the very onset of the delivery, even the scientists went clueless about the way the ball moved. The world of cricket looked surprised with the way the ball traveled opposite to the face of the seam. It took a series of scientific research to break the code of this Pakistani menace.
An old ball has its surface almost out of shape. The wear and tear of the ball hitting the pitch, the ground, the bat, the fielders, the cracks for overs after overs erase its initial spherical shine over time. Now, when the ball is released with an inclined seam, the air becomes turbulent over both the halves of its surface.
The air traveling over the seam is turbulent for the uneven nature of the seam. However, the air on the other end gets even more turbulent for moving across the rough surface of the ball. Hence, air on this half holds lesser pressure than the air through the seam.
This gap in this pressure forces the ball to deviate opposite to the seam of the ball. This is why the ball travels to the reverse direction, unlike in case of the traditional mode of swing.
Reverse swing is a rare skill in cricket. Only a handful number of pace bowlers could execute this mode of swing bowling over the last four decades. Added with speed, reverse swing can be lethal for batsman due to false anticipation. While a batsman decides the way of swing looking at the seam position on the grip of the bowler, the ball travels in the opposite way, causing dismissals such as leg before wicket, bowled or caught off the edge.
Once again, reverse swing is tough to achieve in limited overs cricket, due to the short duration of Twenty20s, or the use of two new balls in modern One Day Cricket. Test cricket is the ideal format to exercise reverse swing, given the ample amount of time the old ball stays in play.
Effect of Weather Conditions
The swing on the ball could be influenced by a number of factors. The mystery behind the extra swing in pink ball owes it to two such factors – the color of the ball, and moisture.
Keeping the pink ball factor apart, often the new ball can be seen swinging too much under the cloudy skies or on a damp pitch. Although no theory explains the direct relationship between these, credits go to the moisture content in air for this incident.
Overcast conditions make the air heavy with water vapor. A cricket ball has rotational motion off its seam apart from the linear one during a delivery. Under influence of the moisture on damp pitches, this rotational motion faces turbulence. In turn, an extra lateral push forms due to Magnus effect – another law of physics.
This extra force adds up to the original swing of the ball, causing more trouble to the batsmen. This is why certain swing bowlers with extraordinary stats under the cloud often faces criticism for their dependency on weather conditions.
Effect of the Color of the Ball
Currently, balls of three colors are used in international cricket – red, white and pink. While the red ball takes its turn in test cricket, the white ball dominates the shorter formats. On the other hand, the latest addition of day-night test cricket finds the use of the pink ball.
Why different color in different formats
Red is the traditional color used in a cricket ball since the inception of the sport. The color of red has the highest wavelength among the visible colors to eyesight. In other words, the human eye can watch red from the farthest of distance among all colors. Against the white clothing on field, red has the highest clarity to the players. Also, test cricket takes place under the daylight.
All these factors prove why red is the best choice for conventional test cricket. However, as the limited over format entered the arena, red could not grasp its place in this form of the game. The One Day cricket involved playing under floodlight in the evening. The yellow floodlight made the red ball look brownish, that is tough to interpret for a batsman. Also, introduction of colored clothing in cricket played a big role on this context. Hence, white balls were launched which is equally visible in both daylight and under floodlight.
However, the white ball did not suit in the idea of day-night test cricket. It is because, the white ball wears off too soon. Test cricket requires a ball to be in play for at least 80 overs, which not possible with the white ball. Hence, the pink ball emerged with fresh capabilities to be part of this new format. Not only the pink ball is visible both in daylight and under floodlight, it contains an extra coat of pink dye that does not let it wear off too soon.
Color and Swing
The red, white and pink balls exhibit different characteristics in terms of swing. While the white ball provides conventional swing for a shorter time than the red ball, the amount of swing is more on white ball than the red one. As explained earlier, there is minute chance for contrast or reverse swing from a white ball while both are regular with a red ball.
On the other hand, the pink ball brings more swing than the white and the red. Also, it provides conventional swing for more amount of the time than the red ones. In addition, it produces surplus swing during the twilight session of play. However, it loses all swing once it gets soft, so it cannot produce much contrast or reverse swing.
To know why the pink ball contains such an extraordinary swing facility, we must know about the scientific relation between the color of the ball and the swing it produces.
The Coloring Process
The color of a cricket ball is actually the color of dye applied on the leather coating of the ball. The swing capabilities of the cricket ball depend on its coloring procedure. The white color attracts dirt quickly than any other color. It is the same reason why two new balls are used in ODIs these days, as the batsmen earlier found the dirty ball less visible during the late overs of an innings. Hence, the white ball is manufactured with an extra layer of polyurethane to preserve its white color for longer period of time.
This layer in turn makes the surface of the ball extra smooth. As a result, the amount of lateral swing in the first 10 overs found is pretty higher than that in test cricket. However, the white ball contains only four layers of stitching, which is why it loses its shape rapidly. Due to this, the white ball holds conventional swing for a comparatively less amount of time than the red one.
On the other hand, the pink ball goes through a separate manufacturing process. In fact, it is the actual secret behind the mysterious swing that the pink ball produces.
The Extra Lacquer on Pink Ball
Unlike the white ball, the pink ball must be playable for at least 80 overs. To meet this condition, an initially dyed ball in pink color gets an extra layer of pink pigments around itself. This extra pink lacquer helps to keep the shine of the ball intact for a longer time. It makes sure the ball does not get old too soon unlike the white ball under similar day-night cricketing conditions. Also, it increases the visibility of the ball under floodlight.
In addition, this extra lacquer holds major responsibility for the excess swing that the pink ball produces. Since it makes the surface of the ball smoother for a long time, it helps the conventional swing stay longer. In fact, if the red ball swings for a maximum of first 15 overs, the pink ball supports swing throughout a whole session of 30 overs!
The Twilight Session
Not only that the pink ball swings for higher duration than the red or white ball, it exhibits higher amount of swing as well. Interestingly, this phenomenon reaches its highest extent during the twilight period. The ball seems to induce a late swing in this moment of play, that makes the life of even top batsmen pretty miserable. For instance, 9 wickets fell during the second day of the historic pink ball test between India and Bangladesh in Kolkata last year. All the nine wickets went to the pacers from both the sides.
As the sun sets and the night sets in, the temperature drops by a significant amount during the twilight period in between. This makes the air cooler, and heavier. Also, the moisture content in air increases. As explained earlier how moisture plays a role in finding extra swing due to the rotational motion of the ball that produces an extra force, the pink ball gains the late swing during this period.
The extra lacquer and the moisture in twilight session are what makes pink ball so dangerous for the batting side. From the statistics of the pink ball test matches, it is quite clear how pace bowlers dominate in this format. Swing indeed is the greatest weapon in their armory in this format of test cricket.
As the Indian team would be playing their first ever overseas pink day-night test in Adelaide, it would be interesting to see the battle of pace and swing, among the likes of Jasprit Bumrah and Mitchell Starc, or Pat Cummins and Mohammed Shami!