by DeltaAlpha » Fri Jun 14, 2013 3:19 pm
It's not easy to explain in a single post, sussex, but, basically it depends on how the 'boundary layers' - the layers of air closest to the ball - behave. These layers will separate from the ball at some point, and the key to swing bowling is to get the one on one side to separate earlier than the one on the other side.
With reverse swing, the boundary layer on the off side (the side to which the seam's pointing) is separated by interaction with the seam - that's why a prominent seam helps. The one on the leg side will separate some time after it has passed the centre of the ball - how much after depends on how rough that side is; the rougher, the later, within reason.
If you can visualise that, you'll see that the layer on the leg side separates later than the one on the off side - even if the leg side's shiny - and this deflects the air flow to the off side. By the conservation of momentum, the ball will then tend to move to the leg side.
I did a thread on swing bowling soon after I joined CMS - I'll dig it up if anyone's interested.
Last edited by
DeltaAlpha on Fri Jun 14, 2013 3:25 pm, edited 1 time in total.
2011-12 CMS winter chess champion
2011 CMS spring chess champion