Leg before wicket, commonly known as lbw, is a form of dismissal introduced, primarily to prevent the batsman from deliberately protecting the stumps with his pads.
The leg before decision is the most complicated decision of the lot as the standing umpire will have to consider various aspects before he can deliver a verdict.
The umpire can adjudge a batsman lbw if in his opinion the ball would have travelled to disturb the stumps provided the pads were not in its path of motion.
However, there are certain clauses the umpire will have to take into consideration before the batsman can be given out. Firstly, if the ball has pitched outside the line of the leg stump the umpire cannot rule a batsman out.
Secondly, if the batsman has attempted a stroke and contact with the ball on the pads is made outside the line of the off stump, then the umpire cannot rule the batsman out.
But, if batsman has not offered a stroke and if the contact of the ball on the pads is outside the line of the off stump, then the umpire may rule the batsman out.
The batsman cannot be given out lbw if the ball is deflected off the bat on to the pads - commonly known as bat-and-pad. Lbw decisions are generally contentious with most batsmen unhappy with the umpire's decision.