Law 36 of the MCC's laws of cricket still has peoples' heads in a spin - exactly how does the lbw law work? To the uninitiated, the leg before wicket dismissal is to cricket what the offside law is to football. But the lbw law is not as complicated as some people may think. It is governed by certain principles which, once mastered, make the law simple to understand. And that is exactly what this guide will aim to do!
The umpire will consider an lbw decision if he believes the ball would have hit the stumps had its path not been obstructed by the batsman's pads or body. But the umpire also has to take certain factors into consideration before making a decision.
The three stumps
There are three stumps that make up a wicket.
They are the off stump, middle stump and leg stump.
From a bowler's perspective, the off stump is to the left of middle stump.
And the leg stump is to the right of middle stump.
This is reversed for a left-handed batsman.
Not out: Ball pitches outside leg stump
The most important factor when an umpire considers an lbw decision is whether the ball pitched outside leg stump.
If the ball lands outside the line the of leg stump, the batsman cannot be given out - even if the ball would have gone on to hit the stumps.
Not out: Bat before pad:
A batsman cannot be given out if the ball hits the bat before the pad.
Not out: Outside line of off stump:
A defence against an lbw appeal for a batsman is to get his pad outside the line of off stump.
An umpire will turn down any appeal if he believes the ball has struck the batsman's pad outside the line of the off stump, even if the ball would have gone on to hit the stumps.
Out: Offering no stroke
...the batsman makes no genuine attempt to play a stroke.
The outside off stump defence becomes redundant.
Batsman is out
In this situation, the ball has pitched on the stumps and has struck the batsman on the pads in front of the wicket.
The ball has not pitched outside the line of leg stump.
And it has not struck the batsman outside the line of off stump.
Therefore the umpire should give the batsman out.
But a lot of the time it is never this simple...
Yet more considerations
The umpire must also consider four other variables:
The height of the ball's bounce Swing and spin of the ball Where the ball hit the pad Whether the batsman is attempting to play a stroke.
Height of the ball's bounce
Each pitch tends to have its own idiosyncrasies which must also be taken into account by the umpire.
Some are faster, harder and bouncier than others, which means the ball will bounce higher than on a slower pitch.
In those circumstances, the umpire must decide whether the ball would have gone over the stumps after striking the pad.
Swing and spin
Bowlers often swing the ball in the air or make the ball spin when it pitches on the wicket.
So if the ball strikes the batsman's pad, the umpire must assess how much the ball would have moved had it not struck the pad.
Would it have swung or spun enough to hit the stumps? Or would the ball have moved too much and missed the stumps completely?
Where the ball strikes the pad
Batsmen can create doubt in an umpire's mind by taking a big stride down the pitch with their front foot.
By moving further down the pitch, the batsman lengthens the distance between the ball and the stumps.
If he is struck on the pad a long way down the pitch, the umpire has a more difficult job to assess whether the ball would have gone on to hit the stumps.
But if a batsman is struck while on his back foot or back pad, there is a shorter distance to judge between the batsman and the stumps, strengthening the bowler's appeal for an lbw decision.
Is the batsman playing a stroke?
The umpire must consider if the batsman is making a genuine attempt to offer a stroke.
Sometimes, especially to spinners, batsmen can intentionally hide their bat behind the pad, making it unclear as to whether they are playing a shot or not.
This is a very defensive move designed to frustrate bowlers.
However, it can be difficult to judge, so it comes down to the discretion of the umpire.
Umpires under pressure
Lbw appeals happen within the space of two seconds, often less.
During that time the umpire has to assess numerous factors before arriving at their final outcome.
The increasing role of technology has brought even greater scrutiny to lbws.
TV viewers can see a decision from numerous angles with the help of computer software which can predict swing and spin.
But the umpire has only one chance to get the decision right.