The Decision Review System (DRS) in cricket explained

How does a DRS review work?

After an on-field decision, the batter or fielding captain makes a T shape with their hands. The third umpire studies the replays and technology and tells the on-field umpire whether to keep or overturn the call.

What technology does DRS use?

• Ball-tracking, which projects the ball's path for LBW decisions.
• Edge detection such as UltraEdge, which uses sound to show whether the ball touched the bat.
• Slow-motion replays from several camera angles.
• Thermal imaging such as Hot Spot, in some series.

What does umpire's call mean?

When ball-tracking shows the ball only clipping the stumps or the line, the evidence is too thin to overturn the original decision. The on-field call stands, and the reviewing team keeps its review.

How is an LBW checked on review?

Ball-tracking answers three questions in order. Did the ball pitch outside leg stump? If it did, it can't be out. Did it hit the pad in line with the stumps, unless the batter offered no shot? Would it have gone on to hit the stumps?

Only when all three point to out does the third umpire give it, and marginal answers on the last two fall into umpire's call.

How long does a player have to ask for a review?

Under ICC playing conditions, 15 seconds from the on-field decision. That is why captains consult the bowler and keeper so quickly, and why a review signalled after a long chat can be refused.

Where did DRS come from?

It was first trialled in a Test series between India and Sri Lanka in 2008 before becoming part of international playing conditions. Ball-tracking and sound-based edge detection now do most of the work.

How does DRS affect live betting?

• Markets are usually suspended during a review and reopen at new prices once the decision is final.
• An overturned wicket can swing session and match prices sharply, so avoid betting while a review is running.
• A side with no reviews left is more exposed to a wrong decision late in an innings.
• Settlement follows the final decision after any review, not the first signal on the field.

Our live betting tips cover how in-play prices react to moments like these.