#NewsBytesExplainer: Decoding the role of DRS in reviewing lbw decisions
The Decision Review System (DRS) provides assistance to match officials in decision-making. During the match, players may ask the on-field umpire to refer the decision to the third umpire if they feel he has made a mistake. Leg-before-wicket is one of the most commonly reviewed decisions as the on-field umpire has a split-second to react. Here is how DRS helps in reviewing such decisions.
What is lbw?
To determine the usage of DRS in lbw decisions, we need to understand the dismissal. Leg-before-wicket is a type of dismissal wherein the ball strikes straight on any area of the batsman's body (except hands) in front of the stumps. An lbw appeal gets redundant if the batsman gets struck in front, but the ball is pitched outside the leg stump.
Use of DRS in lbw decisions
Notably, both batting and fielding side can ask for a referral after the on-field umpire's decision. The fielding side opts to review when the original decision is not-out and players feel confident about it being overturned. Paradoxically, the batsman uses the referral after the umpire raises his finger in the first place. He may consult his batting partner, who usually has a clear picture.
What are the factors involved in reviewing lbw decisions?
The third umpire uses a number of elements to dig deep into the decision. Slow-motion replay helps the umpire to check the front foot no-ball. In some nations such as England and Australia, infra-red cameras are available, which decipher if there is an inside edge. 'Snicko' is another technology used to discern edge detection. The final step of reviewing is 'ball tracking' or 'hawk-eye'.
How does ball tracking work?
The ball tracking system is further divided into three segments- pitch (of the ball), impact and wickets (hitting or not). 'Pitch' derives the area wherein the ball has landed (in-line or outside). 'Impact' is the point where the ball comes in contact with the batsman (in-line or outside) The 'wickets' section determines if the ball would have gone on to hit the stumps.
The final decision if the ball doesn't hit stumps directly
On-field umpire's original decision stands if the ball only clips leg or off stumps. In this case, the final verdict is now known as 'umpire's call'. As per the previous rule, the ball had to be hitting half or more area of stumps to be given out. After 2016, the hitting zone increased to the outer layer of the leg and off stumps.
How is a review retained?
Although the final decision rests with the on-field umpire in case of 'umpire's call', the side taking the review retains it due to lack of clear evidence. The review is only lost when the DRS system carves out a clear verdict regarding the dismissal.
