How does a cricket ball swing if it has shine on both sides?

If theres shine on one side, then the streamlines of force come into action.

But what about the Brand new ball with shine on both the sides?

When it comes to cricket, the phenomenon of swing bowling is fascinating and can be quite complex. You’re right in noting that the shine on the ball plays a crucial role in how it behaves in the air. Let’s break down how a cricket ball can still swing even when both sides are shiny, particularly when it’s brand new.

The Basics of Swing Bowling

Swing bowling occurs due to the differential airflow around the ball as it travels through the air. When a bowler delivers the ball, the way it is held and released can create varying pressure on either side, affecting its trajectory. Typically, one side of the ball is kept shiny while the other side is rough, which helps create the conditions for swing.

Understanding Airflow and Pressure Differences

Even with a brand new ball that has shine on both sides, swing can still occur, albeit in a different manner. Here’s how:

• Initial Conditions: When the ball is new, it is perfectly round and smooth, which means it can still create some level of differential airflow. The seam of the ball plays a significant role in this process.
• Seam Position: The seam can be angled in a particular direction. This angle can help create turbulence on one side of the ball, even if both sides are shiny. The seam acts as a disruptor in the airflow, causing one side to experience more drag than the other.
• Bowler's Technique: The way a bowler grips and releases the ball can also influence swing. If the bowler maintains a consistent seam position and uses wrist and finger position effectively, they can still achieve swing.

Types of Swing

There are two primary types of swing: conventional swing and reverse swing. With a new ball, you are primarily looking at conventional swing.

• Conventional Swing: This occurs when the ball is relatively new and has a shiny side and a rough side. However, even with a new ball, if the bowler can create a slight difference in airflow due to seam position, they can still achieve some swing.
• Reverse Swing: This typically happens with an older ball where one side is significantly rougher than the other. The rough side creates more turbulence, allowing the ball to swing in the opposite direction of the shiny side.

Practical Example

Imagine you’re riding a bicycle. If you tilt your body slightly to one side while riding straight, you’ll notice that you can steer the bike in that direction. Similarly, when a bowler tilts the seam of the ball, it can create a ‘tilt’ in the airflow, causing the ball to swing in that direction, even if both sides are shiny.

Conclusion

In summary, while the shine on both sides of a brand new cricket ball may seem like it would negate swing, the seam position and bowler’s technique can still create the necessary conditions for swing. Understanding these dynamics can enhance your appreciation of the skill involved in swing bowling and the intricacies of the game itself.