Cricket’s Decision Review System (DRS) combines on-field judgement with replay technology to examine close calls. This guide explains how a review works, what ball tracking and edge detection show, why “umpire’s call” can leave a decision unchanged, and which DRS details viewers should check before judging a team’s strategy.
Overview
DRS is a process that allows a team to ask the third umpire to examine a disputed on-field decision. It is not a replacement for the on-field umpire. Instead, the system gives the match officials additional evidence when a decision falls within the reviewable areas covered by the competition’s playing conditions.
The exact number of reviews, time allowed to request one, and technology available can differ between formats, tournaments and governing-body regulations. For that reason, a live broadcast’s graphic or the official playing conditions should be treated as the final reference for a particular match. The general workflow, however, follows a familiar pattern:
- An on-field umpire makes a decision, or a reviewable incident occurs.
- The captain or batter communicates a review request within the permitted time.
- The third umpire checks whether the request is valid and identifies the correct decision-making sequence.
- Available replays and technologies are examined, often beginning with whether the ball made contact with the bat.
- The third umpire reports the evidence and final outcome to the on-field umpire.
- The on-field umpire communicates the decision and the team’s remaining reviews are updated where applicable.
A review is therefore more than a single slow-motion replay. It is a structured assessment of the original call, the evidence available, and the standard required to change that call.
What to track
Review time limits and eligibility
A team cannot usually wait until the next delivery to decide whether it wants a review. The request must be made within a short window after the decision, commonly shown on broadcasts as a countdown. In many elite playing conditions, that window is around 15 seconds, but the applicable competition rules take priority.
Only certain decisions can be reviewed. A team may challenge an adjudication such as out or not out, while a review of a routine wide or no-ball call may be governed by separate provisions. The captain or batter must also make the review signal correctly. If the request is late or invalid, the third umpire may not examine the incident as a formal review.
On-field decision and review outcome
Always note the original call before watching the replay. The starting decision matters because the review process does not simply ask whether the ball might have produced a different result. It asks whether the available evidence is strong enough to overturn the on-field decision under the applicable review standard.
A review can generally produce three broad outcomes:
- Decision overturned: The evidence supports a different result, so the on-field decision changes.
- Decision upheld: The evidence supports the original call or does not establish a reason to change it.
- Umpire’s call: The technology reaches a marginal result within the prescribed tolerance, so the original decision remains in place.
Edge detection and audio evidence
For caught-behind and bat-pad questions, the third umpire may use replay footage, sound-based technology and other available broadcast evidence to determine whether the ball touched the bat. A visible deviation alone is not always conclusive: the ball can change direction after contact with the pad, glove or ground. Likewise, a sound must be considered alongside the video because spikes can come from more than one source.
The key question is usually whether there was a bat contact before the ball reached the wicketkeeper or fielder. If there was no bat contact, the review may proceed to other relevant elements, such as leg-before-wicket conditions.
Ball tracking, impact and the wicket zone
Ball tracking is a technological projection of the ball’s path. In an lbw review, it helps officials assess three linked questions: where the ball pitched, whether it hit the batter in line with the stumps, and whether it would have gone on to hit the stumps. These elements should be considered separately.
Ball tracking is not a measurement of the ball’s actual path after it disappears behind the batter. It uses recorded data and a projected trajectory. That is why the impact point and predicted wicket zone are presented with a degree of tolerance rather than as an unlimited guarantee of precision.
Why umpire’s call matters
“Umpire’s call” means the tracking result is close enough to a boundary that the original on-field decision is retained. It can apply to a marginal pitching, impact or wicket result, depending on the review rules in force. It does not mean the technology failed, nor does it mean the umpire ignored the replay. It means the evidence falls within the accepted margin for leaving the original judgement undisturbed.
This can create apparently unequal outcomes. For example, two similar lbw reviews may produce different final decisions because one began as out and the other began as not out. The projected path may be similar, but the original call and the applicable review threshold are part of the decision.
Retained reviews and format differences
Review allowances are competition-specific. Teams may receive a set number of reviews per innings, and some playing conditions distinguish between reviews lost after a clear failure and reviews retained when the final result is umpire’s call. Concussion replacements, front-foot no-balls, short runs and other incidents can also have rules that differ from the standard review sequence.
Do not assume that a Test, one-day international, T20 international, domestic league or franchise match uses identical allowances. When analysing a team’s DRS strategy, record the competition, innings, reviews available at the start and the status after each decision.
Cadence and checkpoints
For live cricket coverage, use a simple checkpoint after every review:
| Checkpoint | What to record | Why it matters |
|---|---|---|
| Original call | Out, not out, wide, no-ball or another reviewable decision | Sets the starting point for the review |
| Review request | Which team requested it and whether it was within time | Shows the decision-maker and procedural validity |
| Technology used | Replay, edge detection, ball tracking or another available tool | Explains what evidence shaped the result |
| Final outcome | Overturned, upheld or umpire’s call | Separates a successful challenge from a retained decision |
| Review balance | Reviews remaining for each team | Measures future tactical freedom |
At the end of an innings, compare the reviews used with the moments that were not challenged. This is more useful than counting successful reviews alone. A team may use a review to remove uncertainty around a key batter, protect a bowler from a costly decision, or preserve its final review for a later phase.
How to interpret changes
A successful review is not automatically a good review, and an unsuccessful review is not automatically careless. Judge the decision using the information available at the time. A captain may reasonably challenge a high-value wicket when the replay is difficult to see, particularly if the team has reviews available and the match situation makes the potential gain significant.
Look for patterns rather than isolated incidents. Repeated reviews against the same batter can suggest that a team has identified a clear lbw or edge vulnerability, while repeated reviews lost on marginal calls may indicate poor communication or an overreliance on the bowler’s appeal. The game state matters too: a review in the final overs of a close chase carries a different strategic value from one early in an innings.
When writing a post-match analysis, separate three questions:
- Was the review technically successful?
- Was it a sensible risk given the match situation?
- Did the result change the team’s remaining options?
For broader match context, pair the DRS log with the scorecard and over-by-over events. Our guide to reading a cricket scorecard can help place each review alongside wickets, partnerships and required run rates, while the post-match review framework offers a wider method for assessing turning points.
When to revisit
Return to this guide whenever a tournament begins, a format changes, or the match broadcast introduces a different review allowance or technology label. Competition playing conditions can alter the number of reviews, the time limit, retained-review treatment and the incidents eligible for review. Those details should be checked before publishing a live update or making a strong claim about a team’s DRS usage.
For a practical match-day routine, confirm the competition rules before the toss, note the review allowance on the live score page, and update the balance immediately after every review. During a contentious decision, identify the original call, wait for the complete ball-tracking or edge-detection sequence, and distinguish “upheld” from “umpire’s call.” After the match, review each challenge in context rather than judging it solely by the final graphic.
That approach makes DRS easier to follow during live cricket and produces more balanced match analysis when a decision becomes a talking point.
