Adjudication
By convention, dismissal decisions are handled primarily by the players - thus if the dismissal is obvious the batsman will voluntarily leave the field without the umpire needing to dismiss them. If the batsman and fielding side disagree about a dismissal then the fielding side must appeal to the umpire who will then decide whether the batsman is out. In competitive cricket, many difficult catching and LBW decisions will be left to the umpire; if a batsman acknowledges that he is out in such cases and departs without waiting for the umpire's decision it is known as "walking", and regarded as an honourable but controversial act.
If the umpire believes he has incorrectly dismissed a batsman, he may recall him to the crease if he has not already left the field of play. A recent example of this was in the 2007 Lord's test match between England and India when Kevin Pietersen was initially given out caught behind, but was recalled when television replays showed that the ball had bounced before being taken by Mahendra Singh Dhoni.
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