Today during the India vs Bangladesh test match, Ishant Sharma was warned by the umpire for stepping on the danger area while bowling. What is this danger area and why are bowlers not supposed to step on it? Also are they punished for stepping on it even after the warning?
The 'Danger Area', or 'The Protected Area', is defined in the MCC Laws of Cricket: Law 41 - Unfair Play:
41.11 The protected area
The protected area is defined as that area of the pitch contained within a rectangle bounded at each end by imaginary lines parallel to the popping creases and 5 ft/1.52 m in front of each, and on the sides by imaginary lines, one each side of the imaginary line joining the centres of the two middle stumps, each parallel to it and 1 ft/30.48 cm from it.
This Protected Area is deemed to be the normal area in which the ball will bounce when bowled by the bowler. Therefore stepping in this area during the bowler's follow-through could be seen as an intentional act to try and damage/scuff this area, which could lead to an unfair advantage to the bowling side, as balls pitched in this area could deviate considerably to where they would normally go.
As for punishments, the bowler is given two warnings by the umpires, and on their third offence in the innings, they are removed from the bowling attack immediately, and may not bowl again for the rest of the innings:
41.13 Bowler running on protected area
41.13.1 It is unfair for a bowler to enter the protected area in his/her follow-through without reasonable cause, whether or not the ball is delivered.
41.13.2 If a bowler contravenes this Law, at the first instance and when the ball is dead, the umpire shall
caution the bowler and inform the other umpire of what has occurred. This caution shall apply to that bowler throughout the innings.
inform the captain of the fielding side and the batsmen of what has occurred.
41.13.3 If, in that innings, the same bowler again contravenes this Law, the umpire shall repeat the above procedure indicating that this is a final warning. This warning shall also apply throughout the innings.
41.13.4 If, in that innings, the same bowler contravenes this Law a third time, when the ball is dead, the umpire shall,
direct the captain of the fielding side to suspend the bowler immediately from bowling. If applicable, the over shall be completed by another bowler, who shall neither have bowled any part of the previous over, nor be allowed to bowl any part of the next over. The bowler thus suspended shall not be allowed to bowl again in that innings.
inform the other umpire of the reason for this action.
inform the batsmen and, as soon as practicable, the captain of the batting side of what has occurred.
The umpires together shall report the occurrence as soon as possible after the match to the Executive of the offending side and to any Governing Body responsible for the match, who shall take such action as is considered appropriate against the captain, any other individuals concerned and, if appropriate, the team.