How DRS Works in Cricket Explained Simply

Cricket is a game of inches. One wrong umpiring call can change the entire direction of a match. To fix this problem, the ICC introduced the Decision Review System or DRS which allows players to challenge on-field decisions using advanced technology.

But how exactly does DRS work? What happens once a player signals for a review? And why do some reviews end in “Umpire’s Call” rather than a clear yes or no? This guide breaks it all down in the simplest way possible.

What Is DRS in Cricket?

DRS full form in cricket is Decision Review System. It is a technology-driven process that helps correct potential errors in on-field decisions. Think of it as a second opinion but powered by cameras, sensors, and ball-tracking software.

Before DRS existed, players had zero say in overturning a bad call. If the umpire’s finger went up, you walked no questions asked. The system was first trialled in a Test match between India and Sri Lanka in 2008 and was officially rolled out for all Test matches in November 2009. It was later extended to ODIs in 2011 and T20 Internationals in 2017.

Who Can Take a DRS Review?

Not everyone on the field can call for DRS. The rules are strict:

• If the batsman is given out, only that batsman can request a review.
• If the fielding team disagrees with a “not out” decision, only the fielding captain can make the call.
• No input from the dressing room is allowed players on the field must decide themselves.

The player signals a review by making a “T” shape with both hands at head height, pointing it toward the on-field umpire.

The 15-Second Rule — DRS Timer

Once the ball is dead, the challenging team has exactly 15 seconds to signal a review. This timer prevents teams from waiting to see reactions from the dressing room before deciding. If the 15-second window passes without a signal, the review request is rejected.

How Many Reviews Does Each Team Get?

Each team receives 2 unsuccessful reviews per innings across all formats of international cricket:

Key rule: You only lose a review if your challenge fails. If the on-field decision is overturned in your favour, your review count stays the same. This rewards accurate reviewing and punishes guessing.

Step-by-Step: What Happens During a DRS Review?

Here is exactly what happens from the moment a player signals for DRS:

1. Signal — The batsman or fielding captain makes the “T” sign within 15 seconds.
2. Umpire Acknowledges — The on-field umpire communicates the review to the Third Umpire via radio.
3. No-Ball Check — Before anything else, the Third Umpire checks if the delivery was legal. If it is a no-ball, the batsman cannot be out regardless.
4. Technology Review — Depending on the type of dismissal, the Third Umpire uses Hawk-Eye, UltraEdge, Hot Spot, or ultra-motion cameras.
5. Decision Delivered — The Third Umpire delivers the verdict. The on-field umpire then upholds or reverses the original decision.

The Technology Behind DRS Explained Simply

Hawk-Eye (Ball-Tracking)

Hawk-Eye uses multiple high-speed cameras around the ground to map the ball’s path from the moment it leaves the bowler’s hand. For LBW reviews, it predicts where the ball would have gone if the batsman’s leg had not been in the way would it have hit the stumps or missed them? Because this is a prediction and not a certainty, a margin of uncertainty is built in, which leads to “Umpire’s Call” (explained in the next section).

UltraEdge / Snickometer

This technology uses extremely sensitive microphones placed near the stumps and pitch to detect even the faintest sound when the ball makes contact. The sound is converted into a waveform on screen. If there is a spike in the waveform at the exact moment the ball passes the bat — that suggests an edge.

Hot Spot

Hot Spot uses infrared cameras to detect heat. When the ball makes contact with the bat or pad, a small friction mark appears as a white heat spot on the infrared image. This confirms whether the ball struck the bat before anything else. Note: Hot Spot is not always available it depends on the broadcast setup for that particular series.

Ultra-Motion Cameras

For run-outs, stumpings, and close boundary catches, the Third Umpire uses super slow-motion footage from multiple camera angles to determine whether the batsman was in the crease, the ball was caught cleanly, or a fielder touched the rope.

What Is Umpire’s Call in DRS?

This is probably the most confusing part of DRS for fans. Here is a simple explanation:

When Hawk-Eye is used for an LBW review, it checks three things:

• Pitching — Did the ball pitch in line with the stumps (or outside leg)?
• Impact — Did the ball hit the batsman’s leg in line with the stumps?
• Hitting — Would the ball have hit the stumps?

For each check, there is a zone of uncertainty built into the technology. If the predicted path of the ball clips the edge of the stumps or only just clips the impact line, it falls within this zone and the verdict becomes Umpire’s Call.

Umpire’s Call means: “The technology cannot say definitively either way — so we trust the on-field umpire’s original decision.”

This is intentional. The ICC designed DRS to correct clear errors, not override every marginal call. Crucially, if a review results in Umpire’s Call, the challenging team retains their review even though the original decision stands.

What Decisions Can Be Reviewed via DRS?

DRS can be used for the following decisions:

• LBW decisions — Was the ball going on to hit the stumps?
• Caught-behind decisions — Did the ball touch the bat or glove?
• Run-outs and stumpings — Was the batsman inside the crease?
• Boundary decisions — Did the fielder touch the rope? Four or six?
• Catches at bat-pad or close-in positions — Was it a clean catch?

What cannot be reviewed: No-balls, wides (in international cricket), and penalties.

Player Review vs Umpire Review

There are actually two types of DRS reviews:

Player Review — Initiated by the batting or fielding team when they disagree with a decision. This is the most common type fans see on TV.

Umpire Review — The on-field umpire can also refer certain decisions directly to the Third Umpire without a player requesting it. This usually happens for run-outs, stumpings, and tricky boundary calls where the umpire is genuinely unsure.

DRS in IPL vs International Cricket

The IPL has its own DRS rules that differ slightly from international cricket:

• In IPL, teams can review wide ball decisions not permitted in ICC matches.
• IPL DRS usage can vary based on the tournament’s playing conditions for that season.
• Not all domestic T20 leagues worldwide use DRS due to the high cost of the technology.

Why DRS Has Changed Cricket Forever?

Before DRS, some of the most talented batsmen in the world were dismissed by howlers decisions that anyone watching on TV could see were clearly wrong. Now, those errors are largely eliminated in the formats where DRS is in use.

It has also changed how captains and players think. A fielding captain who wastes reviews early in an innings gives the opposition a psychological edge. Knowing when to challenge — and when to save your review for later — has become a real skill in itself.

You can see how those high-pressure DRS moments played out in the biggest game of 2026 in our T20 World Cup 2026 Final match report.

Frequently Asked Questions