Summary
A technology-based system that allows players to challenge on-field umpiring decisions using ball-tracking, UltraEdge, and video replays.
Full Explanation
The Decision Review System was first trialed in a Test match between India and Sri Lanka in 2008 and has since become a standard feature of international cricket.
DRS comprises several technologies: - Hawk-Eye ball tracking for LBW decisions - UltraEdge (formerly Snicko) for edge detection using sound waves - HotSpot infrared imaging (used by some boards, now largely discontinued) - Multiple camera replays for catches, stumpings, and run-outs
Each team gets a limited number of unsuccessful reviews per innings — typically 2 in Tests and 1 in limited-overs cricket. A review is retained if the on-field decision is overturned.
The system was controversial from the start. India's BCCI initially refused to adopt DRS, citing concerns about the technology's accuracy. They only accepted it after being on the wrong end of several decisions. The "umpire's call" component remains the most debated aspect — when ball tracking shows the ball is only marginally hitting the stumps, the on-field decision stands.
Key Points
- •Teams get 2 unsuccessful reviews per innings in Tests, 1 in LOIs
- •Review retained if on-field decision is overturned
- •Uses Hawk-Eye, UltraEdge, and video replays
- •India initially refused to adopt DRS
- •Umpire's call applies when ball is marginally hitting stumps
- •Third umpire makes the final decision after reviewing evidence
Notable Controversies
- •India's BCCI refused to use DRS until 2016, creating unfair situations in bilateral series
- •Umpire's call has been criticized as inconsistent and unfair
- •2011 World Cup semifinal — India vs Pakistan played without DRS despite being available
- •HotSpot technology abandoned due to inconsistency and cost
- •Soft signal controversy — removed in 2022 after years of complaints
Related Rules
Umpire's Call
When DRS shows the ball is only marginally hitting the stumps (less than 50%), the on-field umpire's original decision stands — cricket's most controversial modern rule.
Hawk-Eye Ball Tracking
Computer vision technology that tracks the trajectory of the cricket ball and predicts its future path, used primarily for LBW decisions in DRS.
UltraEdge / Snickometer
Sound-based technology that detects edges by analyzing audio waveforms alongside video footage, used in DRS for caught-behind and LBW decisions.
Third Umpire Protocols
The third umpire sits off the field with access to TV replays and technology, assisting with run-outs, stumpings, catches, boundaries, and DRS reviews.