Brook's side
International Regular
Line and Length, “You can usually write the Lords Test as a win for Oz.”
Mackembhoy, “Almost like we don't prepare pitches to suit us. Overheads in the northern grounds helping us to win games not pitches.”
Starfighter, “Complete opposite. It's movement off the pitch that has caused Australian batsmen the most trouble in England.”
Spark, “A general reminder to all that seam movement is far harder to play than swing.”
Ashes 81, “The overhead conditions in England , particularly in the north, don't just impact the amount of swing a bowler gets but also the amount of seam movement. Headingley is probably the worst for this. I've seen countless times the ball do all sorts off the pitch in one session when it's overcast. Then the sun comes out and the pitch suddenly becomes much more docile.”
Xix2565, “Right, because movement due to the ball hitting the ground is impacted more by the air above than the ground below. Next you'll say pitches can't be prepared to suit types of bowling.”
Chin Music, “I am pretty sure that Boycott always said about Headingley, "don't look down, look up!" meaning that it might look a green deck but would play a lot truer if the sun was out and the weather was set fair. Quite honestly if the weather is reasonable you know that Lord's and Oval will likely more be batting decks, but everywhere else will be a mixed bag.”
Ashes 81, (to Xix2565) “Mate if you don't know that in the North of England the atmospheric conditions impact the amount of seam movement then there's nothing I can say to help you. As someone who has lived, played and watched cricket in the North of England all my life, I must have had it wrong all these years along with millions of others.”
Xix265, “Not as much as the actual surface, come on ffs. The ball is literally changing directions after hitting the ground, how is that more the work of atmospheric conditions? It's indirect at best. It's like saying spin is down to atmospheric conditions.”
Ataraxia (to Ashes 81), “Genuinely interested – how does this occur?”
Ashes 81, “No idea mate to be honest but it definitely does happen.”
Data Scientist (to Ataraaxia), “Movement is caused by a difference in drag between the two sides of the ball. There's a few mechanisms by which this can happen. In conventional swing the shiny side faces less drag so it moves faster and the ball moves towards the dull side. The opposite happens for reverse swing. The relationships between the mechanisms are highly complex and non linear. The two parameters that are commonly used to model these things are the mach number and the reynolds number. Mach number is the speed of the ball relative to the speed of sound in air, and the reynolds number is about how sticky the air is relative to how hard the object is to accelerate. Both of these are affected by the atmospheric conditions of the air.”
Ataraxi, “Very interesting, but I was asking how seam is affected by atmospheric conditions. Know anything if that?”
Andruid, “I am guessing that it would be indirectly through the influence of temperature and humidity on the ground?”
Line and Length, “Humidity is definitely a big factor. As a club bowler I never moved the ball a great deal through the air but, on the few days when Perth was experiencing humid weather, I found conditions gave me the swing that I usually lacked.”
Starfighter, “That's nothing to do with movement off the pitch, which is the point of contention here - that atmospheric conditions affect the amount of seam movement, not swing. BTW there has never been any evidence found in tests that humidity affects swing. There is some evidence that small-scale turbulence does, which may explain the cloudy/not cloudy distinction (broadly, less solar heating means less turbulence).”
Xix2565, “Thank you, I still don't get why people are confused about the point being contested.”
Line and Length, “I wasn't referring to movement off the pitch. I simply was expressing my observations of the atmospheric conditions on the degree of swing. This is a view I shared with Bob Massie, with whom I had the pleasure of opening the bowling. Bob had returned from England and apparently lost the degree of swing for which he was famous. He blamed that loss to the drier Perth air in summer.”
Starfighter, “The original point of contention was. If you and some other posters had paid more attention, you'd've realised….That's still anecdote and Massie was not known to swing the ball much in most conditions after '72. The day-to-day and hour-to-hour variations in humidity would be far more important than any perceived average.”
Line and Length, “I had been paying attention thank you. i Was simply commenting on other posts regarding movement through the air and atmospheric conditions.”
Starfighter, “Dude, the comment you were replying to was about the alleged affect of atmospheric conditions on seam claimed by Ashes81.”
Mackembhoy, “Almost like we don't prepare pitches to suit us. Overheads in the northern grounds helping us to win games not pitches.”
Starfighter, “Complete opposite. It's movement off the pitch that has caused Australian batsmen the most trouble in England.”
Spark, “A general reminder to all that seam movement is far harder to play than swing.”
Ashes 81, “The overhead conditions in England , particularly in the north, don't just impact the amount of swing a bowler gets but also the amount of seam movement. Headingley is probably the worst for this. I've seen countless times the ball do all sorts off the pitch in one session when it's overcast. Then the sun comes out and the pitch suddenly becomes much more docile.”
Xix2565, “Right, because movement due to the ball hitting the ground is impacted more by the air above than the ground below. Next you'll say pitches can't be prepared to suit types of bowling.”
Chin Music, “I am pretty sure that Boycott always said about Headingley, "don't look down, look up!" meaning that it might look a green deck but would play a lot truer if the sun was out and the weather was set fair. Quite honestly if the weather is reasonable you know that Lord's and Oval will likely more be batting decks, but everywhere else will be a mixed bag.”
Ashes 81, (to Xix2565) “Mate if you don't know that in the North of England the atmospheric conditions impact the amount of seam movement then there's nothing I can say to help you. As someone who has lived, played and watched cricket in the North of England all my life, I must have had it wrong all these years along with millions of others.”
Xix265, “Not as much as the actual surface, come on ffs. The ball is literally changing directions after hitting the ground, how is that more the work of atmospheric conditions? It's indirect at best. It's like saying spin is down to atmospheric conditions.”
Ataraxia (to Ashes 81), “Genuinely interested – how does this occur?”
Ashes 81, “No idea mate to be honest but it definitely does happen.”
Data Scientist (to Ataraaxia), “Movement is caused by a difference in drag between the two sides of the ball. There's a few mechanisms by which this can happen. In conventional swing the shiny side faces less drag so it moves faster and the ball moves towards the dull side. The opposite happens for reverse swing. The relationships between the mechanisms are highly complex and non linear. The two parameters that are commonly used to model these things are the mach number and the reynolds number. Mach number is the speed of the ball relative to the speed of sound in air, and the reynolds number is about how sticky the air is relative to how hard the object is to accelerate. Both of these are affected by the atmospheric conditions of the air.”
Ataraxi, “Very interesting, but I was asking how seam is affected by atmospheric conditions. Know anything if that?”
Andruid, “I am guessing that it would be indirectly through the influence of temperature and humidity on the ground?”
Line and Length, “Humidity is definitely a big factor. As a club bowler I never moved the ball a great deal through the air but, on the few days when Perth was experiencing humid weather, I found conditions gave me the swing that I usually lacked.”
Starfighter, “That's nothing to do with movement off the pitch, which is the point of contention here - that atmospheric conditions affect the amount of seam movement, not swing. BTW there has never been any evidence found in tests that humidity affects swing. There is some evidence that small-scale turbulence does, which may explain the cloudy/not cloudy distinction (broadly, less solar heating means less turbulence).”
Xix2565, “Thank you, I still don't get why people are confused about the point being contested.”
Line and Length, “I wasn't referring to movement off the pitch. I simply was expressing my observations of the atmospheric conditions on the degree of swing. This is a view I shared with Bob Massie, with whom I had the pleasure of opening the bowling. Bob had returned from England and apparently lost the degree of swing for which he was famous. He blamed that loss to the drier Perth air in summer.”
Starfighter, “The original point of contention was. If you and some other posters had paid more attention, you'd've realised….That's still anecdote and Massie was not known to swing the ball much in most conditions after '72. The day-to-day and hour-to-hour variations in humidity would be far more important than any perceived average.”
Line and Length, “I had been paying attention thank you. i Was simply commenting on other posts regarding movement through the air and atmospheric conditions.”
Starfighter, “Dude, the comment you were replying to was about the alleged affect of atmospheric conditions on seam claimed by Ashes81.”
