DRS in Cricket: The Decision Review System Explained
The Decision Review System (DRS) lets teams challenge on-field umpiring decisions using technology. Learn how DRS works, when teams can use it, and what happens when a review is made.
What Is DRS?
The Decision Review System (DRS) is a technology-based system used in international cricket to review on-field umpiring decisions. It was introduced by the ICC in 2009 and is now used in all major international formats — Tests, ODIs, and T20Is.
How Reviews Work
- An on-field umpire makes a decision (usually LBW or caught behind)
- The dismissed batter or fielding captain challenges the decision
- The player uses the T-sign with their hands to signal a review
- The third umpire checks the decision using available technology
- The original decision is either upheld or overturned
- If overturned, the fielding team retains their review; if upheld, they lose one
How Many Reviews Per Team?
| Format | Reviews Per Innings |
|---|---|
| Test matches | 2 per innings (each team) |
| ODI cricket | 2 per innings (each team) |
| T20 internationals | 1 per innings (each team) |
Technologies Used in DRS
- Hawk-Eye ball tracking: predicts ball path for LBW decisions
- Ultra Edge / Snicko: audio and waveform analysis to detect bat-ball contact
- Hotspot: infrared imaging to show heat marks from impact
- Multiple HD camera angles: for run-outs, stumpings, and catches
What DRS Cannot Be Used For
DRS cannot be used for no-balls (which are checked separately in some competitions), wides, field placement violations, or to review a decision where neither the batter nor fielding captain challenges. Once a player indicates 'not reviewing' by walking away from the crease, the window to review closes.
Frequently asked questions
When was DRS introduced in cricket?
DRS was first used in the 2009 Test between India and Sri Lanka. Full rollout across international cricket took several years, with India initially resistant to adopting the system.
What is Umpire's Call in DRS?
Umpire's Call means the ball-tracking prediction is within the margin of uncertainty for pitching or impact. The on-field decision stands and the reviewing team retains their review.
Can a captain request a review for any reason?
No. Reviews are limited to specific decision types — primarily LBW, caught behind, run-out, stumping, and catches. Captains cannot review a wide, no-ball, or fielding placement.