DRS in Cricket — Complete Guide to the Decision Review System
How the Decision Review System (DRS) works in cricket — the technology involved, review limits, Umpire's Call, and how DRS has changed the game.
What Is the DRS?
The Decision Review System (DRS) allows players to challenge on-field umpiring decisions using technology. Each team is allocated a set number of reviews per innings (typically two in Tests, one per match in T20Is). A team retains their review if the on-field decision is overturned; they lose it if the decision stands. DRS covers LBW and caught-behind decisions — not wide or no-ball calls.
The Technology Involved
DRS combines three key technologies: Hawk-Eye (ball-tracking to predict whether an LBW would have hit the stumps), Hot Spot (infrared imaging to detect ball-bat contact), and Ultra Edge / Snickometer (audio waveform analysis to detect the moment of contact). Not all tournaments use all three — some domestic T20 leagues use only ball-tracking and edge detection.
Umpire's Call
Umpire's Call is applied when the ball-tracking data shows the ball hitting the stumps within a small margin — meaning if the ball was precisely on the edge, the original umpire's decision stands. Umpire's Call for height (pitching outside leg) and impact-outside-off-stump are separate criteria. When Umpire's Call applies, the reviewing team does not lose their review.
How DRS Has Changed Cricket
DRS has fundamentally changed how LBW decisions are adjudicated. The 'Umpire's Call' debate remains contentious — critics argue the margin is too wide, making clear hits look like tight decisions. Strategically, DRS forces batters to be more aware of where balls pitched and whether they hit outside the line. Fielding teams use reviews more tactically — 'captain's reviews' trying edge-catches that were very marginal.
Frequently asked questions
How many DRS reviews does each team get in a Test match?
Each team receives two DRS reviews per innings in Test cricket. If a review overturns the on-field decision, the review is retained; if the on-field decision stands (including Umpire's Call), the review is lost.
What is Umpire's Call in DRS?
Umpire's Call applies when ball-tracking technology determines the ball was hitting the stumps but within the defined margin of uncertainty (typically the edge of the stumps). In this case the on-field decision stands and the reviewing team does not lose their review.
Does every country use DRS?
Most international cricket now uses DRS, but historically India resisted its introduction until 2016. Some bilateral series in developing cricket nations still play without DRS due to technology costs. ICC events have required DRS for all major tournaments since around 2010.