DRS History: How the Decision Review System Changed Cricket

The Decision Review System (DRS) was introduced to international cricket in 2009 and became mandatory for ICC events in 2011. It uses multiple technologies to review on-field umpire decisions, reducing high-profile errors and changing how batters and fielding captains approach the game.

Introduction and Early Controversy

DRS was first used in the 2008 India-Sri Lanka Test. When the BCCI objected to mandatory DRS adoption in 2009-2011 — partly citing inaccuracies in ball-tracking — bilateral series involving India did not use DRS for several years, creating a two-tier system in international cricket.

The Technologies

• Hawkeye/Ball Tracking: predicts the ball's trajectory to determine LBW decisions
• UltraEdge/Snickometer: detects sound deflections to identify edge catches
• Hot Spot: infrared imaging system that shows heat friction from bat edges (used less in modern DRS)
• Hawk-Eye: the proprietary system used for ball-tracking; accurate to within 5mm

How Teams Use Reviews

Each team gets 2 reviews per innings in Tests (1 in T20Is and ODIs with just 2 per innings). A review is retained if the on-field decision is overturned; lost if the decision stands. Teams with good DRS discipline — reviewing only genuinely close decisions — have a clear strategic advantage.

DRS Today

DRS is now accepted universally, including by the BCCI in Test cricket since 2016. It has eliminated many of cricket's most egregious umpiring errors and made marginal LBW and caught-behind decisions far more accurate. Critics argue it has slowed the game's pace, though most agree the sport is more fair for its introduction.