This is from Bob Woolmers website:
IS there any particular reason that the reverse swing thing isnt as much as it used to be in case of Pakistani bowlers. Is it due to the reason that when the ball is ready to reverse swing then the ball is changed because the color becomes dark?
REPLY BY: BOB, (08 Sep 2004, 19h10:02)
Hi Omer Tariq,
Yes lush outfields, more cameras more vigilat refs and Umps, checking the ball. Reverse swing is more likely to occur on rougher outfileds and tracks or when fingers start roughing up the ball!
BW Bob
Is he saying (or hinting) that Pakistani bowlers tamper the ball and thats how they get reverse swing more than any other bowlers in the world?