By "polishing" an older ball (say 30-40 overs) on one side only, especially in damp weather, what happens is that the polished side has less air-friction and thus moves faster than the unpolished side, causing turn in mid-air.
well u actually have to hold ur fingers in a particular angle on the seam of the ball. To swing the ball into the wickets hold your middle and index finger across the seam and angle the ball into leg...
If you have slips next to the wicket keeper, all you need to do is point the seam to the closest to the keeper and you will get a late swing, if you point it to the furtherest away slip you will get...
The bowlers and the teammates used to make the ball shine on one side. When the bowler bowls with the seam , if he shining side of the ball is on one side then it cuts the air due to friction and the...