Using the DRS Review: When Batsmen and Captains Challenge Decisions
The Decision Review System (DRS) allows teams to challenge on-field umpiring decisions using ball-tracking and edge-detection technology. This article explains how DRS reviews work, when batsmen and captains choose to review, and the analytical and psychological considerations behind the review decision.
How DRS Works
The Decision Review System (DRS) is the ICC's technological framework for reviewing on-field decisions. Each team receives a limited number of reviews per innings (typically 2 per side in Tests, 1 per side in T20Is). When a decision is contested, the fielding captain or the dismissed batsman signals a review by making a 'T' shape with hands. The third umpire then reviews the delivery using: Hawkeye ball-tracking (for LBW decisions — tracking the ball's trajectory to determine whether it would have hit the stumps); UltraEdge or Snickometer (for caught-behind or caught-in-the-field decisions — detecting sound or vibration at the moment the ball passes the bat); and Hot Spot (infrared imaging that can detect contact between ball and bat or bat and pad in specific conditions). The third umpire's decision either upholds (overturns the on-field decision) or dismisses (confirms the original decision) the review.
When to Review: The Batsman's Decision
A dismissed batsman must decide instantly whether to review — the review signal must be made before the on-field umpire leaves the dismissal position (typically within 15 seconds). The batsman's review decision is based on: certainty of no contact with the bat for caught-behind or caught decisions (if the batsman is certain the ball hit the pad not the bat, reviewing an LBW decision is stronger — if there was possible bat contact, the edge-detection technology may show it and confirm the dismissal); awareness of where the ball pitched for LBW (the ball must pitch in line or outside off stump for LBW to be given — a batsman who felt the ball pitched outside leg stump has a strong reason to review); and intuition about ball-stump trajectory (experienced batsmen develop a feel for whether a ball hitting their pad was going to hit the stumps or miss). Reviews used on uncertain decisions are often wasted — the review is most valuable when the batsman is genuinely confident the decision was wrong.
Captains and the Review Strategy
The fielding captain's review decision (reviewing not-out decisions) involves different considerations: the captain can consult with the wicketkeeper (who had the clearest view of whether there was an edge) and the fielding slip cordon before signalling; the captain should review when they believe there is significant evidence of an edge that the on-field umpire missed, or when the ball appeared to hit the stumps but the umpire gave not out. Strategic DRS management: some captains save their reviews for the late innings (when opposition wickets are most valuable) rather than using them freely in lower-stakes moments. If a team runs out of reviews before the innings ends, they cannot challenge any decision — making review conservation a legitimate tactical consideration in tightly contested matches.
Frequently asked questions
What is 'umpire's call' in DRS?
'Umpire's call' is used in DRS when the ball-tracking prediction falls within the margin of uncertainty around the stumps — specifically when the ball is predicted to clip the outside edge of the stumps (within 2.5cm) or when the impact zone of the ball with the batsman's pad falls at the very edge of the crease. In these 'umpire's call' situations, the on-field umpire's original decision stands regardless of what the ball-tracking suggests the delivery would have done. The umpire's call concept acknowledges that ball-tracking technology has a margin of error — predictions of ball trajectory after pitch impact are not 100% certain, so in genuinely marginal cases the field umpire's judgment is preserved. Importantly, an 'umpire's call' upholding a not-out decision also preserves the reviewing team's review (since the technology was inconclusive).
Can a team review a no-ball decision?
Yes — no-ball decisions can be reviewed in specific circumstances. From 2023 onward (subject to ICC regulation updates), DRS expanded to cover front-foot no-ball review requests in some tournaments — the third umpire can check whether the bowler's front foot landed behind or on the crease. However, the primary DRS purpose remains batsman dismissals: LBW decisions, caught-behind decisions, and caught-in-the-field decisions are the most reviewed categories. No-balls are also reviewed 'proactively' in some tournaments by a third umpire who monitors every delivery independently — in this format, the teams don't need to use a review for no-balls as they are automatically checked.
How accurate is Hawkeye ball-tracking?
Hawkeye ball-tracking has a published uncertainty of approximately 2.5-5mm at the plane of the stumps — meaning its prediction of whether a ball would hit the stumps has a small but real margin of error. This is why the 'umpire's call' zone exists: balls predicted to clip the edge of the stumps within the uncertainty range are treated as inconclusive. Hawkeye accuracy for pitching position (where the ball landed) is higher — this determination uses multiple camera angles and is more reliable. The technology has improved significantly since its cricket introduction in the early 2000s — the current system's accuracy is widely accepted as sufficient for the decisions it is used for, with the umpire's call provision protecting against the residual uncertainty.