How the Umpire Review Process Works in DRS Cricket

The Decision Review System (DRS) review process in cricket follows a specific sequence of steps when a player challenges an on-field umpire's decision. The process involves multiple officials, various technologies and specific rules about what can and cannot be overturned. Understanding the complete process from the moment a player signals a review to the final decision explains why DRS reviews sometimes take several minutes and occasionally produce surprising outcomes.

Step 1: The Review Signal

When a batter disagrees with an LBW or caught-behind decision against them, or when the fielding team disagrees with a not-out decision, a player can signal for a review within 15 seconds of the on-field decision being made. The signal is the T-sign — forming a T with the hands while looking toward the on-field umpire who made the decision. The on-field umpire acknowledges the review request and communication goes to the television broadcast team and the third umpire.

The 15-second time limit prevents teams from using the review process to disrupt play or confer about whether to review while the opposition batter prepares for the next delivery. If the time limit expires, the review request is denied and the on-field decision stands. Teams lose their review if the on-field decision is upheld after review — reviews are retained if the original decision is reversed.

Step 2: Technology Assessment

The third umpire reviews the specific aspect of the decision being challenged. For a caught-behind review, Ultra-Edge (or equivalent) audio-visual technology is used to detect whether there was an edge. For an LBW review, Hawk-Eye ball-tracking software is used to determine whether the ball was hitting the stumps and whether an inside edge occurred before the pad impact.

The technologies operate under specific protocols. For an LBW decision under review, the third umpire checks in order: whether the ball pitched in line with the stumps, whether there was an inside edge before the ball hit the pad, and if both are confirmed, Hawk-Eye predicts where the ball would have continued after hitting the pad. If the ball-tracking shows the ball hitting the stumps, the decision depends on where the ball pitched — if outside leg stump, LBW is not possible regardless of the ball-tracking.

Step 3: The Umpire's Call Rule

The most debated aspect of DRS is the 'Umpire's Call' rule. When Hawk-Eye's ball-tracking shows that part of the ball is clipping the stumps — or that part of the ball is missing the stumps — but the margin is too small for certainty, the decision is referred to 'Umpire's Call.' This means the original on-field decision stands regardless of what technology shows. If the on-field umpire gave not-out and ball-tracking shows the ball clipping the outside of the stumps, it remains not-out (Umpire's Call). The reviewing team does not lose their review when the decision stays due to Umpire's Call.

Umpire's Call generates more controversy than any other DRS element. Critics argue that if technology can show the ball is clipping the stumps, the batter should be given out regardless of whether the margin is narrow or wide. Defenders of Umpire's Call note that Hawk-Eye's ball-tracking is a mathematical prediction — not a certainty — and that requiring absolute certainty beyond the ball's radius is more honest about the system's accuracy limitations.

DRS in T20 vs Test Cricket

Teams have two reviews per innings in Test cricket. In T20Is, each team has one review per innings. The scarcity of reviews in T20 cricket makes review decisions more consequential — using a review on a marginal decision and losing it can leave a team without protection against a clearly wrong decision later. Teams that practise good review discipline — only reviewing decisions they are confident are wrong — preserve reviews for the moments when they are most needed.