Summary
When an old ball swings in the opposite direction to conventional swing — a phenomenon mastered by Pakistani bowlers and often linked to ball tampering allegations.
Full Explanation
Reverse swing occurs when the cricket ball is old (usually 40+ overs) and one side becomes rougher than the other. Instead of swinging toward the shiny side (conventional swing), the ball moves toward the rough side.
The physics: When the rough side faces the batsman and the ball is bowled at pace, the turbulent airflow over the rough side creates less drag than the laminar flow over the smooth side, causing the ball to swing in the 'wrong' direction.
Pakistani bowlers Wasim Akram and Waqar Younis are widely credited with mastering reverse swing in the 1990s. Their ability to produce devastating reverse swing led to allegations that they were illegally tampering with the ball — allegations that were never proven against them.
Reverse swing has become a legitimate and admired skill, but the fine line between legal ball maintenance (keeping one side rough naturally) and illegal tampering (artificially roughing one side) remains cricket's greatest grey area.
Key Points
- •Ball swings opposite to conventional swing direction
- •Occurs with old balls (usually 40+ overs)
- •Mastered by Wasim Akram and Waqar Younis in the 1990s
- •Legal to let one side deteriorate naturally
- •Illegal to artificially roughen one side
- •Fine line between legal maintenance and tampering
Notable Controversies
- •Pakistan bowlers faced constant allegations of ball tampering in the 1990s
- •Sandpapergate 2018 — Australia tried to create reverse swing conditions illegally
- •Debate about the two-new-ball rule in ODIs killing reverse swing
Related Rules
Ball Tampering (Law 41.3)
Illegally altering the condition of the cricket ball is a serious offence. Players may shine the ball using natural substances but cannot use artificial materials, scratch, or pick at the seam.
New Ball Rules
Teams can take a new ball after a certain number of overs — 80 in Tests, new ball at the start in LOIs. Different ball brands (Kookaburra, Dukes, SG) behave differently.