Decision Review System and the Controversies behind it
Umpire Decision Review System (UDRS) gives a chance to both the teams to challenge the decisions of on-field umpires. Close run-outs, stumping and unclear catches are already being referred to upstairs. DRS is an added technique of reviewing Leg before decisions (LBW) by using hawk-eye technology (to predict the ball trajectory until the initial impact) and unclear bat-pad catches using hot-spot technology to distinguish the hard and soft impacts.
ICC officially launched the system on 24th November 2009 during the first test match between New Zealand and Pakistan at the University Oval. However, the system was first tried in 2008 in a Test series between India and Sri Lanka in Sri Lanka