DRS in Cricket Explained: How Decision Review System Works, Rules, Umpire’s Call, LBW, UltraEdge & Ball Tracking
DRS in Cricket Explained
How the Decision Review System works: rules, umpire’s call, LBW, ball tracking and UltraEdge.
DRS stands for Decision Review System. It is a technology-based system used in cricket to help umpires check important decisions, especially LBW and caught-behind dismissals. Players can challenge certain on-field decisions, while umpires can also request assistance from the third umpire. DRS uses ball tracking, UltraEdge and video replays to help determine whether the original decision should stand or be changed.
Have you ever watched a cricket match where a batter was given out LBW, but immediately made a T-shaped sign with both hands?
That’s a DRS review.
The Decision Review System has become an important part of modern cricket. It helps reduce clear umpiring mistakes and gives teams an opportunity to challenge decisions.
However, DRS can sometimes be confusing.
What does umpire’s call mean? How does ball tracking predict the ball’s path? Why does a team sometimes keep its review even when the decision doesn’t change?
And how many DRS reviews are allowed in Test, ODI and T20 cricket?
In this guide, we’ll explain everything about DRS in simple English, with examples, rules and easy-to-understand tables.
Last updated: 4 November 2026
What Is DRS in Cricket?
DRS is a system that allows certain decisions made by on-field umpires to be checked with the help of technology.
The third umpire reviews available evidence and advises whether the original decision should stand or be overturned.
For example, imagine a bowler appeals for LBW.
The on-field umpire gives the batter not out.
The fielding captain believes the ball would have hit the stumps and requests a review.
The third umpire checks the delivery using available technology.
If the evidence meets the conditions for LBW, the decision can be changed to out.
This process is called a DRS review.
What Is the Full Form of DRS in Cricket?
The full form of DRS is Decision Review System.
It is also commonly called the Umpire Decision Review System.
DRS Quick Facts
| Question | Answer |
|---|---|
| DRS full form | Decision Review System |
| Purpose | Help review umpiring decisions |
| Main technologies | Ball tracking, UltraEdge and replays |
| Who can request a player review? | Batter or fielding captain |
| Review signal | T-shape with both hands |
| Review time limit | Generally 15 seconds |
| Third umpire’s role | Examine evidence and communicate the decision |
| Main dismissals reviewed | LBW and caught |
| Introduced internationally | 2008, initially on a trial basis |
DRS is designed to improve decision-making, but the system still operates under cricket’s official laws and playing conditions.
How Does DRS Work in Cricket?
DRS follows a structured process.
When a team disagrees with an umpire’s decision, the appropriate player can request a review.
The third umpire then examines the available evidence.
Step-by-Step DRS Review Process
Step 1: The on-field umpire makes a decision
The umpire gives the batter out or not out after an appeal.
Step 2: A player requests a review
The batter or fielding captain makes a T-shaped signal using both hands.
Step 3: The third umpire receives the review
The television umpire checks the incident using the available camera angles and approved technology.
Step 4: The delivery is checked
The third umpire checks whether the delivery was legal and examines the evidence relevant to the appeal.
Step 5: Technology is used
For an LBW appeal, ball tracking may be used. For a possible edge, the umpire may use UltraEdge or another approved sound-based system.
Step 6: The decision is communicated
The third umpire tells the on-field umpire whether the decision should remain unchanged or be reversed.
Step 7: The final decision is announced
The on-field umpire communicates the result to the players and spectators.
The entire process usually takes less than a minute, although difficult decisions can take longer.
How Many DRS Reviews Are Allowed in Cricket?
The number of unsuccessful player reviews depends on the match format and applicable playing conditions.
DRS Reviews in Test, ODI and T20I Cricket
| Format | Unsuccessful reviews allowed |
|---|---|
| Test cricket | 3 per team, per innings |
| ODI cricket | 2 per team, per innings |
| T20 International | 2 per team, per innings |
These are the standard limits used in major ICC international competitions with DRS.
A team does not automatically lose a review simply because the on-field decision remains unchanged.
The result of the review matters.
When Does a Team Lose a DRS Review?
A team generally loses a review when its challenge is unsuccessful.
For example:
A batter is given out LBW.
The batter requests DRS.
Ball tracking shows that the ball would clearly hit the stumps, and all other LBW conditions are satisfied.
The original out decision remains unchanged.
The batting team loses one review.
When Does a Team Keep Its Review?
A team retains its review when the on-field decision is overturned.
It also normally retains the review when an LBW decision remains unchanged because of umpire’s call.
This rule is important because marginal ball-tracking decisions should not automatically cost a team a review.
What Is Umpire’s Call in Cricket?
Umpire’s call is one of the most discussed parts of DRS.
It applies to certain marginal LBW decisions where ball tracking indicates that the ball is close to the edge of the impact or wicket zone.
In these situations, the original on-field decision is retained.
Umpire’s Call Example 1: Batter Given Out
Imagine a batter is given out LBW.
The batter requests a review.
Ball tracking shows the ball clipping the outside of the leg stump.
The result is umpire’s call.
Because the original decision was out, the batter remains out.
The batting team retains its review.
Umpire’s Call Example 2: Batter Given Not Out
Now imagine the same delivery, but the on-field umpire gives the batter not out.
The fielding captain requests DRS.
Ball tracking again shows the ball marginally clipping the stump.
The result is umpire’s call.
Because the original decision was not out, the batter remains not out.
The fielding team retains its review.
Umpire’s Call Explained
| Original decision | Ball-tracking result | Final decision |
|---|---|---|
| Out | Umpire’s call | Out |
| Not out | Umpire’s call | Not out |
| Out | Clearly missing | Not out |
| Not out | Clearly hitting, with other LBW conditions met | Out |
Important: Umpire’s call does not mean the technology has failed. It means the relevant ball-tracking result is marginal under the DRS protocol.
What Is Ball Tracking in Cricket?
Ball tracking is a technology that estimates the trajectory of a cricket ball.
It uses camera information to analyse the ball’s movement and predict where it would have travelled if the batter’s pad had not stopped it.
One of the best-known ball-tracking systems is Hawk-Eye.
How Does Ball Tracking Work?
Special cameras capture the movement of the ball.
The system processes this information and creates a three-dimensional representation of the ball’s path.
For an LBW review, the third umpire uses this information to examine three important factors:
- Pitching
- Impact
- Wickets
These three stages help determine whether the batter can be dismissed LBW.
DRS LBW Rules Explained
LBW stands for Leg Before Wicket.
A batter may be dismissed LBW when a legal delivery hits their body and meets the conditions specified in cricket’s laws.
DRS helps officials check those conditions.
1. Pitching: Where Did the Ball Land?
The first question is where the ball pitched.
The ball may pitch:
- In line with the stumps
- Outside off stump
- Outside leg stump
A batter cannot be given out LBW if the ball pitches outside leg stump.
However, a delivery pitching outside off stump can still result in LBW.
2. Impact: Where Did the Ball Hit the Batter?
The next question is where the ball first hit the batter.
Normally, the impact must be in line with the stumps.
However, there is an important exception.
If the batter makes no genuine attempt to play the ball with the bat, an impact outside off stump can still qualify for LBW under the law.
3. Wickets: Would the Ball Hit the Stumps?
Finally, ball tracking predicts whether the delivery would have hit the wicket.
The result can be:
- Hitting
- Umpire’s call
- Missing
If the ball is clearly missing the stumps, the batter cannot be out LBW.
If it is clearly hitting and all other LBW conditions are satisfied, the batter can be given out.
LBW DRS Decision Table
| Pitching | Impact | Wickets | Typical result |
|---|---|---|---|
| In line | In line | Hitting | Out |
| Outside off | In line | Hitting | Out |
| Outside leg | In line | Hitting | Not out |
| In line | Outside leg | Hitting | Not out |
| In line | In line | Missing | Not out |
| In line | Umpire’s call | Hitting | Original decision may stand |
| In line | In line | Umpire’s call | Original decision stands |
This table assumes a legal delivery, no prior bat contact and a genuine attempt to play the ball unless otherwise stated.
What Is UltraEdge in Cricket?
UltraEdge is a sound-based technology used to help detect whether the ball has touched the bat.
It is particularly useful for caught-behind and LBW reviews.
UltraEdge combines audio information with video images.
When the ball passes the bat, the system displays a sound waveform.
A sound spike at the relevant moment may indicate contact.
However, the third umpire must also consider the timing of the sound and the video evidence.
How UltraEdge Works
Imagine a fast bowler delivers a ball outside off stump.
The batter attempts a drive.
The wicketkeeper catches the ball and appeals.
The on-field umpire gives the batter not out.
The fielding captain requests DRS.
The third umpire checks UltraEdge.
If the evidence confirms that the ball touched the bat and the catch was completed legally, the decision can be changed to out.
What Is Snickometer in Cricket?
Snickometer, often called Snicko, is another sound-based technology associated with detecting possible edges.
It displays sound information alongside the ball’s movement.
A sound spike can help identify possible contact between the ball and bat.
Real-Time Snickometer is one of the technologies approved for use under ICC DRS protocols.
UltraEdge vs Snickometer
| Feature | UltraEdge | Snickometer |
|---|---|---|
| Main purpose | Detect possible bat contact | Detect possible bat contact |
| Uses audio | Yes | Yes |
| Displays sound waveform | Yes | Yes |
| Used for caught-behind reviews | Yes | Yes |
| Used during LBW checks | Yes | Yes |
| Main difference | Technology implementation and provider | Technology implementation and provider |
Both systems support the third umpire, but neither should be treated as perfect evidence without considering the complete incident.
What Is Hot Spot in Cricket?
Hot Spot is a technology that uses infrared cameras to identify possible contact points.
When the ball strikes the bat, pad or another surface, friction may create a temperature difference.
The system can display this contact area.
Hot Spot has been used in international cricket, although it is not available in every match.
Hot Spot vs UltraEdge
| Feature | Hot Spot | UltraEdge |
|---|---|---|
| Technology | Infrared imaging | Audio analysis |
| Main purpose | Identify contact | Identify contact |
| Common use | Edge detection | Edge detection |
| Available in every match? | No | Depends on match technology |
| Output | Thermal contact indication | Sound waveform |
UltraEdge and Hot Spot are different technologies, but both can help umpires assess possible bat contact.
What Is Hawk-Eye in Cricket?
Hawk-Eye is a well-known ball-tracking technology.
It is used to analyse the movement and projected path of a cricket ball.
In DRS, Hawk-Eye can help the third umpire determine whether a delivery would have hit the stumps.
It is particularly important for LBW decisions.
Hawk-Eye vs UltraEdge
| Feature | Hawk-Eye | UltraEdge |
|---|---|---|
| Main purpose | Track ball trajectory | Detect possible edge |
| Technology | Camera-based tracking | Sound-based analysis |
| Common decision | LBW | Caught behind, LBW |
| Predicts ball path | Yes | No |
| Detects sound spikes | No | Yes |
These systems are often used together during an LBW review.
Who Can Take DRS in Cricket?
A player review can be requested by the appropriate member of the team.
When the Batter Is Given Out
The dismissed batter can request a review.
For example, if the umpire gives LBW but the batter believes the ball hit the bat first, the batter may challenge the decision.
When the Batter Is Given Not Out
The fielding captain can request a review.
For example, if the bowler believes the batter is LBW but the umpire gives not out, the captain may challenge the decision.
The bowler can suggest taking a review, but the formal request must come from the fielding captain.
What Is the DRS Time Limit?
Under standard ICC player-review protocols, the request must be made promptly, generally within 15 seconds of the ball becoming dead.
The review signal is made by forming a T shape with both hands.
If a player waits too long, the umpire may refuse the request.
Teams are also not allowed to obtain assistance from people outside the field of play before deciding whether to review.
Can DRS Be Used for Run Outs and Stumpings?
Run-outs and stumpings can be checked by the third umpire.
However, these are commonly handled through umpire reviews rather than the team’s limited player reviews.
For example, if a wicketkeeper removes the bails and the on-field umpire is unsure whether the batter was inside the crease, the umpire can request television assistance.
The third umpire examines the available camera angles.
The final decision depends on whether the batter was safely inside the crease when the wicket was broken.
This process does not normally use up a team’s DRS player reviews.
What Is the Difference Between Player Review and Umpire Review?
There are two main types of reviews.
Player Review
A player review happens when the batting or fielding team challenges an on-field decision.
These reviews are subject to the applicable unsuccessful-review limits.
Umpire Review
An umpire review happens when an on-field umpire requests assistance from the third umpire.
This may involve run-outs, stumpings, boundaries and other situations covered by the playing conditions.
Player Review vs Umpire Review
| Feature | Player review | Umpire review |
|---|---|---|
| Requested by | Batter or fielding captain | On-field umpire |
| Main purpose | Challenge a decision | Obtain assistance |
| Uses team’s review allowance | Yes, if unsuccessful under applicable rules | No |
| Third umpire involved | Yes | Yes |
| Technology used | As relevant | As relevant |
When Was DRS Introduced in Cricket?
DRS was first trialled in international cricket during the India vs Sri Lanka Test series in 2008.
The system was introduced to help reduce clear umpiring errors.
Over time, it became a regular part of international cricket.
Different technologies and review rules have been added or modified since its introduction.
Important Milestones in DRS History
| Year | Development |
|---|---|
| 2008 | DRS trialled in India vs Sri Lanka Test series |
| 2009 | DRS began wider use in international cricket |
| 2011 | DRS used in the ODI World Cup |
| 2017 | Teams began retaining reviews on umpire’s call |
| 2021 | Wicket-zone interpretation updated to include the bails |
| 2025 | ICC updated aspects of review procedures |
The system has continued evolving as technology and playing conditions change.
Important DRS Rule Updates
DRS rules have changed several times.
The ICC periodically updates the playing conditions to improve consistency and decision-making.
One important principle is that an umpire’s call result normally allows the reviewing team to retain its review.
Another important development concerns situations where more than one possible dismissal is involved in the same delivery.
For example, a batter may be given out caught, but a review may show that the ball did not touch the bat.
The third umpire may then need to consider whether the batter could be out LBW.
The applicable playing conditions determine how the original on-field decision is treated in that situation.
Because tournament rules can differ, the latest official ICC playing conditions should always be checked for competition-specific details.
Why Is Umpire’s Call Controversial?
Umpire’s call has created debate among cricket fans and players.
Some people believe that if technology shows the ball touching the stumps, the batter should always be out.
Others believe that marginal decisions should continue to respect the on-field umpire’s judgement.
Arguments Supporting Umpire’s Call
Supporters believe that ball tracking includes a predictive element.
They argue that marginal results should not automatically overturn the original decision.
The rule also recognises that umpires make decisions in real time.
Arguments Against Umpire’s Call
Critics argue that the same delivery can produce different final decisions depending on the original call.
For example, a ball clipping the stumps may result in out in one situation and not out in another.
This can be confusing for viewers.
Despite the debate, umpire’s call remains an important part of the DRS framework.
Is DRS 100% Accurate?
DRS is designed to improve the accuracy of umpiring decisions.
However, it is not correct to describe every part of the system as 100% accurate.
Different technologies have different limitations.
Ball tracking uses recorded data to predict a ball’s path after it strikes the batter.
UltraEdge uses audio and video information to help identify contact.
Camera angles, available technology and interpretation can affect difficult decisions.
For this reason, the third umpire evaluates the evidence under official protocols rather than relying on a single image.
Advantages of DRS in Cricket
DRS has several important benefits.
1. Reduces Clear Umpiring Errors
The system allows obvious mistakes to be corrected.
2. Improves Fairness
Both teams have an opportunity to challenge eligible decisions.
3. Uses Technology
Ball tracking and sound-based edge detection provide information that may not be visible to the on-field umpire.
4. Helps in High-Pressure Matches
Close decisions during World Cups and important Test matches can be examined carefully.
5. Builds Confidence in Decision-Making
The review process provides additional evidence and greater transparency for viewers.
Disadvantages and Limitations of DRS
Although DRS is useful, it has limitations.
1. It Can Interrupt the Match
Long reviews may slow down the game.
2. Umpire’s Call Can Be Confusing
Fans sometimes struggle to understand why the same ball-tracking result can leave different original decisions unchanged.
3. Technology Is Not Perfect
Ball tracking and edge detection have technical limitations.
4. Not Every Match Has Full DRS
The necessary technology may not be available in all competitions.
5. Teams Can Make Poor Review Decisions
Players sometimes request reviews based on emotion rather than strong evidence.
DRS in Test Cricket vs ODI vs T20I
The main DRS principles are similar across formats.
However, the number of unsuccessful reviews differs.
Format-Wise DRS Comparison
| Feature | Test | ODI | T20I |
|---|---|---|---|
| Unsuccessful reviews per innings | 3 | 2 | 2 |
| LBW reviews | Yes | Yes | Yes |
| Caught-behind reviews | Yes | Yes | Yes |
| Ball tracking | When available | When available | When available |
| UltraEdge or approved equivalent | When available | When available | When available |
| Umpire’s call | Yes | Yes | Yes |
The available technology and detailed procedures depend on the match’s official playing conditions.
Common DRS Mistakes Cricket Fans Make
Many viewers misunderstand how the system works.
Mistake 1: Thinking Umpire’s Call Means Not Out
Umpire’s call does not always mean not out.
It means the original decision remains unchanged for the relevant marginal result.
Mistake 2: Thinking Every Unsuccessful Review Is Lost
A team normally retains its review if the decision remains unchanged because of umpire’s call.
Mistake 3: Thinking Ball Tracking Shows the Actual Future
Ball tracking predicts the ball’s path after the point where it was stopped.
It does not show an event that physically happened.
Mistake 4: Thinking UltraEdge Always Proves Bat Contact
A sound spike must be interpreted alongside the video evidence.
Other sounds may occur near the bat.
Mistake 5: Thinking Every Third-Umpire Decision Is DRS
Some third-umpire checks are umpire reviews and do not use a team’s player-review allowance.
DRS in Cricket: Simple Match Example
Imagine India is playing Australia in a Test match.
An Australian fast bowler delivers a ball that hits an Indian batter’s pad.
The bowler appeals for LBW.
The umpire gives not out.
Australia’s captain requests DRS.
The third umpire checks the delivery.
Pitching: In line
Impact: In line
Wickets: Hitting
The third umpire confirms that all LBW conditions are satisfied.
The original not-out decision is overturned.
The batter is given out.
Australia keeps its review because the challenge was successful.
Now imagine the ball-tracking result had shown umpire’s call on the wickets.
The original not-out decision would have remained unchanged.
Australia would still retain its review.
This example explains why the original umpire’s decision matters in close LBW situations.
Frequently Asked Questions About DRS in Cricket
1. What is DRS in cricket?
DRS is a technology-based system used to review certain decisions made by on-field umpires.
2. What is the full form of DRS?
Decision Review System.
3. How does DRS work?
A player challenges an eligible decision, and the third umpire examines video replays and approved technology before communicating the result.
4. How many DRS reviews are allowed in Test cricket?
Three unsuccessful player reviews per team, per innings under standard ICC Test conditions.
5. How many DRS reviews are allowed in ODI cricket?
Two unsuccessful player reviews per team, per innings under standard ICC ODI conditions.
6. How many DRS reviews are allowed in T20 cricket?
Two unsuccessful player reviews per team, per innings under standard ICC T20I conditions.
7. What is umpire’s call?
It is a marginal LBW ball-tracking result that allows the original on-field decision to stand.
8. Does umpire’s call mean out?
Not always. It depends on the original on-field decision.
9. Does a team lose a review on umpire’s call?
Normally, no.
10. What is Hawk-Eye?
Hawk-Eye is a camera-based ball-tracking technology.
11. What is UltraEdge?
UltraEdge is a sound-based technology used to help detect possible bat contact.
12. What is Snickometer?
Snickometer is a system that displays sound information to help assess possible edges.
13. What is Hot Spot?
Hot Spot uses infrared imaging to help identify contact points.
14. Who can request DRS?
The dismissed batter or the fielding captain, depending on the original decision.
15. Can a bowler take DRS?
A bowler can suggest a review, but the fielding captain must formally request it.
16. What is the DRS time limit?
Generally 15 seconds under standard ICC player-review protocols.
17. Can DRS overturn an LBW decision?
Yes, when the evidence satisfies the relevant rules.
18. Can DRS overturn a caught-behind decision?
Yes.
19. Can DRS be used for a run-out?
The third umpire can review run-outs, usually through an umpire review.
20. Can DRS be used for a stumping?
Yes, usually through an umpire review.
21. What does pitching outside leg mean?
The ball landed outside the batter’s leg-stump line, which prevents an LBW dismissal.
22. Can a batter be LBW if the ball pitches outside off stump?
Yes, provided the other LBW conditions are satisfied.
23. What does impact in line mean?
The ball first struck the batter within the relevant impact zone.
24. What does wickets missing mean?
Ball tracking predicts that the delivery would not have hit the stumps.
25. Is DRS completely accurate?
No technology should be assumed perfect, although DRS helps improve umpiring decisions.
26. When was DRS first introduced?
It was trialled internationally in 2008.
27. Which series first used DRS?
The India vs Sri Lanka Test series in 2008.
28. Is DRS used in IPL?
Yes. The IPL uses DRS, with competition-specific playing conditions.
29. Why do players make a T sign?
The T-shaped hand signal indicates a request for a player review.
30. Why is umpire’s call controversial?
Because marginal ball-tracking results can preserve different original decisions.
Conclusion
The Decision Review System has become an important part of modern cricket.
It helps umpires make better decisions and gives teams an opportunity to challenge certain calls.
DRS uses technologies such as ball tracking, UltraEdge and video replays to examine difficult situations.
Understanding the three LBW stages—pitching, impact and wickets—makes it easier to follow most reviews.
Umpire’s call is another important concept because it explains why marginal decisions may remain unchanged.
Although DRS has limitations, it has improved transparency and helped correct clear umpiring mistakes.
The next time you watch a cricket match and see a player making the T-shaped review signal, you’ll have a better understanding of what happens next.
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