DRS Review Process in Cricket Explained

How the DRS Review Process Works

When a player wishes to challenge an on-field umpire's decision, they signal for a review by forming a T-shape with their hands and arms (the review signal). The on-field umpire formally refers the decision to the third umpire, who then analyses the available technology to determine whether the on-field decision was correct. The review must be requested within 15 seconds of the original decision. Each team typically has two reviews per innings in Test cricket, and one review per innings in limited-overs cricket.

Technology Used in DRS

DRS uses multiple technologies simultaneously: ball-tracking (Hawk-Eye or equivalent) traces the ball's trajectory from release to impact, predicting where it would have gone if the batter's pad or bat had not intervened — critical for lbw decisions. Ultra-Edge (or equivalent audio analysis) detects the spike in sound at the moment the ball passes the bat edge — used for caught-behind reviews. Hot Spot (infrared imaging) can detect friction marks where the ball has contacted bat or pad, though it is not universally deployed. The third umpire uses all available evidence to make a decision.

DRS for LBW Decisions

LBW reviews are the most complex DRS adjudications. Ball-tracking must determine: where the ball pitched (if outside leg stump, it cannot be out regardless of impact); whether the ball would have hit the stumps (the Hawk-Eye prediction has a zone of uncertainty near the stumps — the 'umpire's call' zone); and whether the impact was in line with the stumps. If the ball pitches in line and impact is in line, the only question is whether ball-tracking shows the ball hitting the stumps. If the ball is clipping the top of the stumps, this falls in the umpire's call zone and the original decision stands.