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beshideshi
June 8, 2010, 10:31 PM
Hey guys, we all know that when conditions are overcast, temperatures are low...the ball has a mind of its own and swings a large amount. I was having a conversation with one of my friend, and he asked me why does that happen? I had no answer
Everyone knows the ball swings a lot more in overcast conditions, but why does that happen?

AsifTheManRahman
June 8, 2010, 10:40 PM
Humidity. Greater humidity leads to greater air resistance on the rough side of the ball, which in turn leads to greater swing.

deshifan
June 8, 2010, 10:51 PM
You gotta be kidding, right ? /:) Humid air is lighter than dry air. Check it out

http://www.theweatherprediction.com/habyhints/260/
http://wiki.answers.com/Q/Explain_why_humid_air_is_lighter_than_dry_air

first year e thermodynamics chilo na ? :-p
Humidity. Greater humidity leads to greater air resistance on the rough side of the ball, which in turn leads to greater swing.

tonoy
June 8, 2010, 11:21 PM
Although deshifan is partly correct, I think one of the main reason as to why it swings more particularly in England is because during overcast it is much cooler than a normal warm sunny morning. Compared to the differences made by temperature and air pressure, humidity has a small effect on the air's density. But, humid air is lighter than dry air at the same temperature and pressure. I think the prime reason as to why it swings more is because of Colder air along with combination of greater atmospheric pressure.

tonoy
June 8, 2010, 11:36 PM
By the way, I think it's quite a proven fact that overcast condition doesn't assist the bowler achieve any swing.

AsifTheManRahman
June 8, 2010, 11:42 PM
By the way, I think it's quite a proven fact that overcast condition doesn't assist the bowler achieve any swing.
In fact I do remember reading somewhere that it doesn't and that there are three - not two - types of swing bowling. Claimed by a NASA scientist.

beshideshi
June 9, 2010, 12:55 AM
I also recall reading there is a third kind of swing yet to be exploited by bowlers.
And thanks for the explanation Tonoy bro. I myself being a medium pacer have seen the ball do a lot more during a cooler day, and always wondered why that happened :p
So, according to the theories, the pitches will do very little to assist the swing bowlers unless the conditions are right. That means we can only prepare quicker pitches in BD, but not create swing-able conditions, hence our batsmen will always be weak against genuine quality swing bowling. [well, until global warming kicks in and we have freezing winters :p]

Neel Here
June 9, 2010, 02:04 AM
#1 Why does the new ball swing but the old ball doesn't ?
( not talking of reverse-swing which is different.)
this is how out-swing happens.
http://img401.imageshack.us/img401/7839/swingam.jpg (http://img401.imageshack.us/i/swingam.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)

the rough surface presented by the seam the smooth air-flow over the ball's surface is disturbed and it generates vortices at that point. vortices are a lower pressure area than the smooth air-flow area on the opposite face of the ball. hence the ball is kind of sucked-in towards the direction of the vortices. therefore it's all about the position of the seam, so that it generates the highest amount of vortices, higher the amount of vortices, higher the swing.
this is why bowling coaches wax eloquent about seam position after delivery. ;)
if the seam wobbles too much after delivery the vortices will be generated all over the place and the ball might go in any direction or it might get no swing at all.

#2 why doesn't the old ball do normal swing ?
because the seams are worn off ! simple as that. this is also why the SG and duke balls swing for a longer amount of time than kokaburra balls, because their seams maintain shape for a longer amount of time. frequently bowlers complain that they can't find any seam on the kokaburra ball after 10-15 overs.

#3 why does it swing more in humid conditions ?
because the seams absorb moisture and puff up. thus become more prominent(larger) and hence generate more vortices.

for in-swing you just turn the seam by 90 degrees to the right.

al-Sagar
June 9, 2010, 02:15 AM
That means we can only prepare quicker pitches in BD, but not create swing-able conditions, hence our batsmen will always be weak against genuine quality swing bowling

its the same for indians. they havent been able to produce that kind of pitches. swingable pitces for the same reasons.

but we can make seamable piches if we leave enough live grass and bowlers have good grips and release.

i played very little cricket with real cricket ball. for around year in school. and then 2 months in college (only practice and trial for college team, no games). i never had a bowling coach but in a program i saw kapil dev saying what are the grips for swinging or seaming the ball in and out. i always tried it. but got very little in the pitches which were bald.

but oneday while i was warming up bowling beside the pitch in grass, no batsman only WK receiving ball i noticed the ball seaming. after that day i regularly when got chance tried it and saw the difference on bowling grass. and also on days after rain, wet grass, wet days i saw the ball swinging.

well actually those seam and swing never happened in bald pitches i played. very little when i pitched it up almost full toss.

but leave real cricket ball. lets talk about TAPE TENNIS BALL. i was the master of swing in TAPE TENNIS ball in all my school, college and versity days. what i need is let me tape the ball with a little secret. also if somebody else does it i will need three four trial deliveries to asses if there is any glitch in the ball that i can exploit to swing the Tape Tennis ball.

beshideshi
June 9, 2010, 02:27 AM
^^ I have played quite a lot of school cricket in Dhaka, and barely ever found any swing. With the brand new ball, a couple of balls would zip off, and skid a bit quicker than you expect. I looked at Wasim Akram's videos, Kasprowich's video etc, but never found any result in Bangladesh.
For study purposes I moved to Australia and playing grade cricket here, and the amount of swing I get sometimes amazes me. I specially recall one very gloomy day, when the ball was swinging at least a metre. And beating the bat was as easy as getting hit for 4 when bowling to Tamim :P. So as you said, the conditions do have a lot more effect than pitches.
So out only solution would be to send academy/A team players overseas to get a taste of swinging deliveries. :)

Nafi
June 9, 2010, 05:55 AM
Overcast conditions, usually means low pressure, therefore the differences of high pressure(turbulence) on the ball is more significant and greater.

If its sunny, and no clouds, there is high pressure, so the difference is marginal, when high pressure builds on the ball, because the whole environment has high pressure.

AsifTheManRahman
June 9, 2010, 08:16 AM
Here's the article where Rabindra Mehta terms claims of overcast conditions assisting swing bowlers as "rubbish": http://www.timesonline.co.uk/tol/sport/cricket/article6740828.ece

He also talks about the third type of swing I was referring to.

beshideshi
June 9, 2010, 09:36 PM
Here's the article where Rabindra Mehta terms claims of overcast conditions assisting swing bowlers as "rubbish": http://www.timesonline.co.uk/tol/sport/cricket/article6740828.ece

He also talks about the third type of swing I was referring to.

Wow. Great read this. Learnt a lot about swing bowling![right or wrong is a different issue]
So what I thought was reverse swing is actually contrast swing. I used to think if the ball moved away from the rough side, it's reverse swing.
To be honest I don't care what the swing is called as long as it can get the batsmen out :D

Imteaz
June 10, 2010, 01:28 AM
Very Informative. Thanks for the thread :up:

yaseer
June 10, 2010, 04:00 AM
I do not know the science behind it. But from my playing experience in BD, I sometimes able to swing the new ball but neither knew why it was swinging nor could repeat the swing in the next ball.

I did ask to some elder brothers who were playing in premiere that time. They showed me the difference between grip and wrist position for in-swing/out-swing. I tried it, sometimes happened but could not make it happen willingly. Then I talked to them about this, they said even some top bowlers not sure about the ball swing or not. Even it happens that bowlers trying to ball an out-swing but it actually ended up been in-swing. So, my experience was always "jodi hoia jai", but happened a little. But I always found it more probable to swing in grass than in the pitch.

My conclusion is, weather wise you cannot be sure about the ball will swing or not. It may or may not swing in overcast/cloudy condition. But if there is grass, you should be sure to get something out.

BANFAN
June 12, 2010, 02:56 AM
I think the overcast conditions allows more moisture in the air, thus making the wind heavier to be able to move the ball more than light dry air. V = M x A coming into effect?

NB: Just thought, it could be; no lab test conducted by me or no ref. ;)

Rough surfaces in the old ball is much better used for reverse swing, when quick through the lighter air (Sunny) but bowlers who generate good pace could reverse in almost every condition.

bujhee kom
June 12, 2010, 03:42 AM
Dhilaa pants mone hoi. Khoob bataash mone hoi.

beshideshi
June 13, 2010, 01:22 AM
Dhilaa pants mone hoi. Khoob bataash mone hoi.

Sharajibon e joto jaegae joto gulo argument shunsi, tar modhe shobche beshi ortho bahok holo apnar ei jukti. Ekdom noble shanti puroshkar pawar moto ekta kotha bolechen dada.