Decision Review System

DRS Full Form in English, letter by letter

DRS is the Decision Review System, cricket's technology-assisted process for challenging on-field umpiring decisions.

DRS Full Form in Indian Languages

Commentators say "DRS" in English even in Hindi, Tamil or Bengali broadcasts, so the abbreviation is the same everywhere. Below, the Decision Review System is written in six Indian languages.

What the Decision Review System does

The Decision Review System, called DRS by everyone in cricket, lets a team challenge an on-field umpire's decision. The third umpire watches replays, ball-tracking and edge-detection data, and the on-field umpire then reverses the decision or lets it stand.

It was brought in to remove clear mistakes, the kind where a batter is given out off a ball that missed the bat by a foot. Trials were held in 2008, and the first official use in a Test came in November 2009 in a match between New Zealand and Pakistan. After early resistance, including from the BCCI for years, it is now standard in international matches and in the IPL.

Replays are also used for boundaries, run outs and stumpings, but those are referred by the on-field umpires and are not counted against a team's reviews.

The technology behind DRS

Three pieces of equipment do most of the work, and a review usually involves more than one of them.

Ball tracking

Several high-speed cameras follow the ball from release to impact and project where it would have gone after hitting the pad. Hawk-Eye is the best known system. The projection is an estimate with a small margin of error, which is why LBW reviews depend on it so heavily.

UltraEdge and Snicko

Microphones near the stumps record sound that is matched with slow-motion video. A spike on the graph as the ball passes the bat shows whether there was an edge, which is the first thing checked on a caught-behind review.

Hot Spot

Infrared cameras pick up the heat made by friction when ball meets bat or pad. A faint edge shows as a bright mark. Hot Spot has been used in some series and dropped in others because of cost and reliability.

How a review unfolds on the field

Only the batter facing the decision or the fielding captain can ask for a review, and it has to be asked within 15 seconds of the decision, usually after a quick huddle. The on-field umpire makes the T sign with both hands, and the call goes to the third umpire by radio.

For an LBW appeal, the third umpire checks three things in order. Was the ball pitched in line or on the off side, did it hit the pad in line with the stumps, and would it have gone on to hit them. If the ball was hit by the bat first, the LBW question never arises.

Each side gets two unsuccessful reviews per innings in Tests and one in ODIs and T20Is. A review that overturns the decision is not deducted. Until the third umpire reports back, the original decision stands, so players should wait on the field instead of walking off.

Umpire's call, explained with an example

Take a ball that pitches in line and hits the batter's pad in front of middle stump. Ball tracking shows it clipping the top of leg stump, with less than half the ball hitting. The on-field decision stands. If the umpire had given the batter out, the batter stays out. If the umpire had given not out, the batter stays in. In both cases the team that asked keeps its review.

That is umpire's call. It exists because the tracking is a prediction made from limited frames, so a very marginal result is not treated as proof either way. Critics say it keeps wrong decisions on the scorecard. Defenders say it respects the real margin of error and gives the umpire the benefit of the doubt.

Other complaints come up often. Equipment differs from one series to another, so two similar incidents can be judged on different evidence. Long reviews also slow the game, though a fixed order of checks has shortened the waits.

What can and cannot be reviewed

Players can review LBW, caught behind, caught in the field and many other dismissals. Whether wides and no-balls can be reviewed by players has changed between competitions in recent years, so the playing conditions of the particular tournament decide it. The third umpire checks front-foot no-balls on every wicket in international matches anyway.

A common confusion is between a player review and an umpire referral. Run outs, stumpings, boundary decisions and checks for a possible no-ball after a dismissal go to the third umpire without costing a review. A review is spent only when a player challenges a decision made on the field.

How DRS changed captaincy and batting

Reviews are now a resource to be spent, so captains weigh the importance of the wicket, the overs left and how sure the bowler or wicketkeeper is. Many teams nominate one player, often the wicketkeeper, to advise on when to ask. The batter at the non-striker's end is allowed to talk to his partner, which has led to some memorable wrong decisions to walk or stay.

Bowlers and batters have adjusted too. A close LBW that was once simply given or refused can now be checked, so batters stay at the crease after a marginal decision and bowlers keep appealing for balls that look just about to hit the stumps. The mind games around whether to review have become part of the contest itself.

DRS has not made umpires redundant, but it has made the costly errors rarer. Knowing what each tool can prove, and where umpire's call applies, explains most review outcomes you see on TV.

DRS Full Form: Common Questions