Explained: How the DRS works in case of close LBW decision

The Decision Review System (DRS) was a topic of debate in the ICC World Cup match between Pakistan and South Africa in Chennai. South Africa were on the verge of a 271-run target, but Pakistan bowlers took five quick wickets to reduce them to 260/9. With eleven runs needed by South Africa in 4.3 overs and just one wicket between Pakistan and a win, a controversial moment occurred when Haris Rauf bowled to tailender Tabraiz Shamsi, but the umpire turned down Pakistan’s appeal for an LBW.