DECISION REVIEW SYSTEM

DECISION REVIEW SYSTEM

Subject : Science & tech / sports

Context : The International Cricket Council’s (ICC) cricket committee has made changes to the way lbws will be decided under the Decision Review System (DRS).

Concept :

• The “wicket zone”, the area of the stumps a ball must hit for an on-field not-out decision to be overturned, which previously ended below the bails, will now extend all the way up to the top.
• The committee also decided to retain the umpire’s call, an element that allows the on-field decision to stand when there is no conclusive evidence to overturn it.
• A player can also ask the umpire whether an attempt was made to play the ball before deciding to review an lbw call.

What necessitated the review?

• Under DRS, 50% of the ball should predictively hit the “wicket zone” for an on-field not-out decision to be reversed.
• Earlier, if the ball-tracking simulation showed the ball to be clipping the bails, the on-field verdict, even if it was not out, stood because the “wicket zone” ended below the bails.
• This left both players and supporters exasperated because two balls, both predictively shown to be hitting the stumps, can both be out and not out depending on the on-field umpire’s call.
• The 50% test is also applied for balls projected to hit the outside of the off-stump or leg-stump.