Sky Has No Limits...! So Do I....!

The goal of mankind is knowledge. This knowledge is inherent in man. No knowledge comes from outside; it is all inside. What we say a man 'knows', should, in strict psychological language, be what he 'discovers' or 'unveils'; what man 'learns' is really what he discovers by taking the cover off his own soul, which is a mine of infinite knowledge. --------------------------------------------------------------------------- "Swami Vivekananda" - Great Philosopher of the Orient

My previous article on golf ball and the reason for dimples on it, made me to investigate more about the aero-dynamics of the cricket ball. Now lets understand the science behind the swing of the cricket ball..!

As we all know, a cricket ball is made of either 2 pieces or 4 pieces, stitched to form a seam. The seam has 6 rows of stitches with 60 to 80 stitches each row. This is called as the Primary seam. In a 4 piece ball, each hemispheres are stitched together by an internal stitching. This forms the secondary seam.
Flow Dynamics:
Lets first understand the basic flow dynamics of a sphere. When a ball is flying through air, it forms a layer around the ball surface called "The Boundary Layer". This layer cannot travel all over along with the ball. So it has to separate at a point where it is called as "Flow separation". This flow separation determines the pressure. The early flow separation means more pressure and late separation means less pressure. This difference in pressure makes the ball to swing...!
So it is clear that there must be a difference in pressure on either side of the ball to make it swing..!
Now lets see the Boundary Layer more closely...!
The boundary layer has two states. One is laminar flow and other is turbulent flow. The laminar flow is smooth flow with out any disturbance or turbidity. When a cricket ball flies in air, if it does not has any deviation in the position of seam ,then both sides of the ball may have a laminar air flow pattern.


Let us understand the swing of the cricket ball with the seam position being straight...!
This kind of swing does not require expertise bowling skills but of course practice is essential. Observing the above picture, by positioning the seam straight, the ball being rough on one side and smooth on other side, with the average bowling speed less than 70 miles per hour, the ball starts to swing automatically. When we look at the figure, the rough side creates turbulence and thus delays the flow separation. This causes the pressure to reduce on the rough side. When looking at the smooth side, the laminar flow exists, and the flow separation point is seen early than the rough side. This imparts more pressure on the smooth side. Thus the ball swings from high pressure side to low pressure side.
Now lets say the bowler positions the seam towards the slips or away from the right hand batsman, as shown in the above figure. The rough side and the seam produces turbulence, thus delaying the flow separation, causing lesser pressure. On the other side, the smooth surface, renders a laminar flow, with out any disturbance. This creates early flow separation and thus high pressure. So the ball is being pushed from high pressure to low pressure side, i.e , the ball swings away from the batsman, called "OUT SWINGER". When the seam in positioned towards the right hand batsman, then the ball swings into the batsman, called as "IN SWINGER".

So now wondering what is a Reverse Swing...?
The reverse swing is mostly produced only by few bowlers who bowl at a speed of around 85 to 90 miles/hr. This happens because, at such high speeds, the laminar flow becomes turbulent before reaching the ball surface. Thus when the flow hits the seam, the boundary layer becomes more turbulent, making the layer thick and cause early flow separation when compared to bottom side. Thus this again causes the pressure difference, which makes the ball to swing. But to be observed in depths, that the swinging direction is opposite to the seam position...! Thus it is called as reverse swing...!
Thus the science(aero-dynamics) behind the cricket ball is clear and appreciated. Comments and discussions are welcome..!

Bookmark and Share

11 comments:

Hi, nice one there mate breaking things down for newbies although i must add i found something which i thought was fundamentally wrong about your explanation of reverse wing.

Check this out mate: http://www.youtube.com/watch?v=075O6fRJesQ&feature=search

Here is my understanding of swing bowling. I have used the example of bowling an OUTSWINGER to a Right Handed Batsman (RHB):

NORMAL CONVENTIONAL swing.
1, Fast-Medium or Medium-Fast
2, Bowled around 70-80mph
3, New ball only
4, Seam position towards 1st/2nd slip
5, 'Rough' side facing slip (although this isn't really applicable)
6, Ball moves away from RHB

REVERSE swing:
1, Fast or (a few) Fast-medium bowlers
2, Bowled over 85-90mph
3, Generally bowled using an old ball
4, Seam position towards 1st/2nd slip
5, Shiny side of the ball facing slip
6, Ball moves away from RHB

This is my understanding but feel free to point out if there are any flaws. I'll check back in a few days time.

conventional swing is well known in all books

reverse swing :

1, any bowler at any speed, but is noticed more at higher speeds, due to greater inertia effect of reverse rotation of the ball.
2. generally bowled using a ball which has a weight difference between both sides, i.e shiny side has moisture (swet / spit / water) to make it heavier then when new. And the, rough side is dry hence lighter. The rough side is also made lighter then when new, as the leather may have worn down more and lost weight due to this wear and tear.
3. ball seam position towards fine leg, but ball is also angled downwards. The seam position to help the ball move in that direction and the tilt of th ball to eventually help the ball dip in flight.

4 here is the science. the reverse rotation of the ball, causes inertia of that ball on the weighted side, this causes force on this side hence moves the ball in that direction. This is aided by the seam angle and tilt. to maximise reverse swing.
5. the round arm action by the right handed bowler i.e WAQAR YOUNIS , will aid reverse rotation more, so increase the inertia effect, and the round arm will help the seam position and tilt more. waqar swung the ball more then anyone, watch his bowling in super slow motion and you will see seam position is to wards fine leg, and the ball is titled downwards and he actually spins the ball back at the point of release.

the above article is on reverse swing is false. and inaccurate, as in both cases the ball swings in the same direction as according to the diagrams.

Really awesome post! I got best information.

Cricket Ball Manufacturers

Great Post!!! Thanks for sharing.
Have you just started learning and playing the game of Cricket? Are you looking to buy your first Cricket Ball? If Yes, then Cricket Ball is the best choice for you. It’s all available at just a click: Cricket Balls

Thanks for Publishing this Post !!

I have also having a Cricket Club from last 2 years we are using NEXUKE Brand Leather Balls in 2015 and the Company provide me superior quality Cricket Leather Balls as my customized requirement. I really recommended all buyer and traders to purchase this Nexuke Cricket Leather Balls.. I am also sharing the link of a Company Website

Best Cricket Leather Ball Manufacturer

Such a great Post!! Thanks For Sharing. Are you looking export the cricket leather ball.Then we are the leading Cricket Leather Ball Exporter in India.We give the good quality in the manufacturing the cricket ball and we provide the best service in the world.

This comment has been removed by the author.

Appreciate with Kolkata Escorts in West Bengal, Make My Escorts are best escorts agency. Call or Whatsapp for shabby Kolkata Call Girls at reasonable rates.

escorts in kolkata
Chennai escorts
Post Free Adult Classified Ads in India
Delhi independent escorts

Thanks for sharing with us.

Hi guys, Thanks for Sharing amazing and informative blog. I read your full blog it is very helpful for me and everyone.... Enjoy each sensual minute with most sizzling Independent female high-class escorts in Chennai. In my organization, approx 100 or more neighborhood Independent Escorts are available. What's more, approx 50 or more Chennai based model escorts are available. So I am giving Chennai escorts, and furthermore giving Model Escorts in edges of Chennai District. What's more, you can get in touch with me for prominent escort service.

Call Girls in Chennai
independent Chennai Call Girls
Chennai escorts services
Escorts in Chennai
Chennai independent Call Girls
Chennai independent escorts
Chennai Call Girls services

Thank you for sharing!!

Amazing experience after visiting this site which is really full of information and someone have information for.today urdu news is for those who like to read news in urdu.

I am really impressed with the way you write. The creativity that you’ve produced is simply awesome. I’ve become a fan of your writing and I’ve subscribed your blog to regularly read your fresh content.

Pune escorts services | independent Pune escorts | independent Pune call girls

Post a Comment

Website Translation