Almanac Cricket: Middle Australia and the Science of Swing

It probably is no surprise, but I am a traditionalist especially when it comes to cricket.  However, I must say I did enjoy the day/night test in Adelaide.  I’m not sure if it was simply the novelty of the event; the pleasure of being able to watch Test cricket in the evening; or, finally there was a competition between bat and ball.  In reality probably all three.  Time will tell whether day/night Tests are here to stay or, like the NBL in the late ‘80s and ‘90s, is a passing fad.

Prior to the Adelaide Test there was a great deal of discussion about the pink ball.  Would it last?  Does it swing more than the red ball?  When would it swing?  Would players be able to see the ball depending on the time of day?

Much of the discussion was on the swing of the ball.  Anecdotal evidence from the Shield games and some practice sessions was the pink ball swung more than the red ball. This swing was supposedly accentuated during twilight when artificial light started to takeover from natural light.

Over the years there has been speculation on why a cricket ball swings and not all of it has been right. There is only one reason a cricket ball swings and that is due to a relative difference in pressure on one side of the ball compared to the other.  A ball will move from the high pressure side towards the low pressure side.

Coaches and bowlers will be able to comment better on the practicalities of seam position, seam size, shining the ball, and reverse swing.  From a biomechanical perspective the thing they all have in common is they create a pressure difference on the sides of the ball.

There was even speculation the colour of the ball caused more or less swing, i.e. pink made a ball swing more than red.  This is incorrect.  Colour has no influence on the swing of a cricket ball.

However, there is a related reason why the pink ball did appear to swing more than the red ball, which has nothing to do with the colour.  The reason is due to the manufacturing process required to make a pink ball compared to a red ball.  Red balls are dyed completely through.  Pink balls on the other hand are only painted.  To preserve the colour of the ball a different type of lacquer was used on the pink ball compared to what is used on the traditional red ball.  The different lacquer on the pink ball caused different airflow over the ball compared to the red ball.  Effectively this made the pressure difference greater between the sides of the pink ball compared to a red ball.  A greater pressure difference equals greater swing.

If the pink ball had exactly the same lacquer coating as a red ball there would be no difference in the amount the ball’s swing.

Now it’s time to polish, or rub more dirt into, my Blundstones to get ready for the first Test against the West Indies in Hobart.

The Chairman

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