Reverse swing

[howelli]

Has anyone any (concurrent or conflicting) scientific theories to explain the reason why a bowler in cricket can impart reverse swing to a delivery with an older ball?

[landie]

A bowler imparts swing when one side of the ball is polished and the other worn or abraded. During an innings the bowlers will polish one side of the ball only on their trouser leg. They also use moisture from their brow (plus anything else they may be secreting there) to aid the polishing. The other side of the ball is deliberately left rough, or in some instances when the umpire isn't looking, deliberately roughend by the fingernails or other medium.

The shiny side of the ball travels more easily through the air, during a delivery, than the rough, so the bowler will align the ball in his grip to present the shiny side to one or other side of the wicket. The ball will veer toward the rough sideas it travels.

Hence swing bowling.

[howelli]

Yes that's the understanding for conventional swing but the seemingly impossible happens with an older ball and the ball swings towards the shinier side. Thats the problem! How is this so?

[Sligachan14]

I seem to remember someone (a cricketer) saying he thought it might have to do with the amount of sweat, cream etc being rubbed into the shiny side of the ball making it heavier on that side so causing it to tilt in that direction.