At the centre of the extraordinary cheating scandal that has rocked Australian cricket is a piece of tape barely bigger than a fingernail.

The ball-tampering incident has seen Australia become “the laughing stock of the sporting world”, according to cricket legend Adam Gilchrist, but what was the tape used for?

How does ball tampering work? What about the sugar accusations? And what is reverse swing?

Cricket is a funny game full of idiosyncrasies but if you don’t know a googly from your short leg, or are confused about the goings on in South Africa, look no further.

Swing bowling

Firstly, it is important to understand how – and why – a cricket ball swings.

When a ball moves sideways in the air, it is called swing, and the ability to do this is highly prized.

A fast, swinging ball can undo even the world’s best batsmen.

There are two types of swing. An outswinging ball is one that swings away from the batsmen, and an inswinging delivery does the opposite.

A cricket ball generally swings most when it is hard and new.

How does a ball swing

Swing can be achieved in two ways.

One is by using the seam of the ball. When the ball is delivered with the seam at a particular angle to the initial line of flight, it can swing in that direction.

The other way of achieving swing is by altering the condition of the ball.

And it is that Cameron Bancroft was caught out trying to achieve.

This can be done fairly, or unfairly.

To do it fairly, players obsessively polish one side of the ball, while allowing the other to scuff up naturally to create a rougher surface.

Air passing over a cricket ball creates turbulence and having two surfaces of differing conditions can cause the ball to move in the air.

The idea behind this is that air flowing across the rougher side of the ball will encounter more resistance, while the shiny side encounters less, and moves in that direction.

Therefore, players will try and shine the ball on just one side. They can do this only without the use of an artificial substance.

Any other manipulation of the ball is illegal and punishable under the ICC’s Code of Conduct.

Reverse swing

Reverse swing tends to happen when a ball is older and showing more signs of wear, traditionally after 40 or 50 overs.

When getting the ball to ‘reverse’, a bowler with a grip for an outswinging delivery will actually bowl a ball that swings in, and vice versa.

Reverse swing is only possible if the ball is bowled at pace, and because it swings so late, it is a very difficult proposition for batsmen.

Ball tampering

What Bancroft was attempting to do with the tape was to scuff the rougher side of the ball. This is illegal.

For fielding sides, the greater the contrast between the two sides of the ball, the better, but it cannot be done with a foreign object.

The tape allegedly had debris from the pitch on it and was used as a form of sandpaper.

Television cameras clearly showed Bancroft attempting to hide the tape in his pants. Photo: Fox Sports

Theoretically, this would have allowed the Australian bowlers to extract more reverse swing.

Other examples of players trying to tamper with the ball include Shahid Afridi biting one, Sachin Tendulkar picking at the seam and South Africa captain Faf du Plessis, who was shown on television shining the ball with a mint in his mouth.

What’s the deal with the sugar?

Players are allowed to apply saliva and sweat to polish the ball and can chew mints and lollies during matches, as long as they aren’t applied directly to the ball.

The use of sugary saliva is used regularly in the belief it helps create a ‘better’ shine on one side of the ball.

How they were caught

Former South Africa paceman Fanie de Villiers is now working as a commentator.

He revealed that he tipped off the camera crew at the Cape Town Test about possible ball tampering after speculating the visitors were up to no good.

“I said earlier on that if they could get reverse swing in the 26th, 27th, 28th over, then they are doing something different from what everyone else does,” de Villiers told RSN Radio.

“We actually said to our cameramen ‘go out [and] have a look, boys. They’re using something’.

“They searched for an hour-and-a-half until they saw something and then they started following Bancroft and they actually caught him out at the end.”

-with Mike Bruce