someblokecalleddave
Well-Known Member
We started to have this conversation off the back of discussing the swing that is obtainable with some of the Wrist Spin Variations bowled with an upright seam - Flippers etc.
Doctoran Said.................
Let's just explain this magnus effect terminology. A golf ball has crevices on it so that it can go further in the air. Smooth surfaces drag (or experience difficulty moving through the air). Hence on a cricket ball it is harder to go through the air on a smooth side compared to a rough side. The ball swings or seams towards what is rough. The roughest thing on a ball is generally not the side of a ball -- BUT THE SEAM (on a brand new ball)! The more pronounced it is the more effect you will see. To maximise the swing you want it as smooth as possible so that the force is directed onto the direction of the ball.
Drift happens the same way. With large rotations, a nice seam, and a ball that isn't too roughed up... the ball will move in the direction of the seam.
Air is heavier than people think. "One cubic metre of air at ground level weighs 1210 gm. A cricket ball weighs 160 gm. A room full of air weighs more than most cricket players." (University of NSW). Imagine the difference that humidity, and even differing air pressures and hence air densities could make. Wind is essentially caused by high pressure wind particles moving towards low pressure areas. If you're in a stiff gale you are in an area in between two largely different air pressure zones (could be hundreds or thousands of kilometres apart). High pressure means lots of air which means accentuation of the effects of swing and spin.
Therefore wind at the WACA can make the ball swing and drift more. Rough surfaces in India can make the ball drift less. And big seams do make the ball drift and swing more.
P.S. don't get me started on reverse swing
I then said in response -
That I'd just looked at a bunch of weather charts and the potential for his theory regarding atmospheric pressure affecting the outcome of the way that the ball moves through the air. My initial searches were inconclusive, so I've now gone back to some basic questions..............
So going back to the cricket ball scenario here we get the ball swinging when there's low pressure - anticyclonic weather, when the cloud cover is low and the atmosphere muggy. So that fits with every other situation. Needless to say then we struggle in Australia because the weather during your summer would be dry and sunny, high pressure and little moisture.
Does that then mean that as Brisbane is in a sub tropical area, at some times in the year you'd expect moisture laden starts to the day that would then quickly burn off and be replaced by blazing hot sunshine? At this time of year is that the case- does the day start muggy/humid and potentially offer swing conditions?
So lets get Doctoran started on swing and reverse swing and anyone else that wants to join in.
Doctoran Said.................
Let's just explain this magnus effect terminology. A golf ball has crevices on it so that it can go further in the air. Smooth surfaces drag (or experience difficulty moving through the air). Hence on a cricket ball it is harder to go through the air on a smooth side compared to a rough side. The ball swings or seams towards what is rough. The roughest thing on a ball is generally not the side of a ball -- BUT THE SEAM (on a brand new ball)! The more pronounced it is the more effect you will see. To maximise the swing you want it as smooth as possible so that the force is directed onto the direction of the ball.
Drift happens the same way. With large rotations, a nice seam, and a ball that isn't too roughed up... the ball will move in the direction of the seam.
Air is heavier than people think. "One cubic metre of air at ground level weighs 1210 gm. A cricket ball weighs 160 gm. A room full of air weighs more than most cricket players." (University of NSW). Imagine the difference that humidity, and even differing air pressures and hence air densities could make. Wind is essentially caused by high pressure wind particles moving towards low pressure areas. If you're in a stiff gale you are in an area in between two largely different air pressure zones (could be hundreds or thousands of kilometres apart). High pressure means lots of air which means accentuation of the effects of swing and spin.
Therefore wind at the WACA can make the ball swing and drift more. Rough surfaces in India can make the ball drift less. And big seams do make the ball drift and swing more.
P.S. don't get me started on reverse swing
I then said in response -
That I'd just looked at a bunch of weather charts and the potential for his theory regarding atmospheric pressure affecting the outcome of the way that the ball moves through the air. My initial searches were inconclusive, so I've now gone back to some basic questions..............
So going back to the cricket ball scenario here we get the ball swinging when there's low pressure - anticyclonic weather, when the cloud cover is low and the atmosphere muggy. So that fits with every other situation. Needless to say then we struggle in Australia because the weather during your summer would be dry and sunny, high pressure and little moisture.
Does that then mean that as Brisbane is in a sub tropical area, at some times in the year you'd expect moisture laden starts to the day that would then quickly burn off and be replaced by blazing hot sunshine? At this time of year is that the case- does the day start muggy/humid and potentially offer swing conditions?
So lets get Doctoran started on swing and reverse swing and anyone else that wants to join in.