No ball

In the sport of cricket a No ball is a penalty against the fielding team, usually as a result of an illegal delivery by the bowler. For most cricket games, especially amateur games, the definition of all forms of No ball is from the MCC Laws of Cricket, although youth cricket often has stricter rules on beamers, and international cricket has stricter rules on beamers, but laxer rules on bouncers.

The delivery of a No ball results in one run – two under some Regulations – to be added to the batting team's score, and an additional ball must be bowled. In addition, the number of ways in which the batsman can be given out is reduced except for run out. In shorter competition cricket, a batsman receives a 'free hit' on the ball after any kind of No ball (see below). This means the batsman can freely hit one ball with no danger of being out in most ways.

No balls due to overstepping the crease are not uncommon, especially in short form cricket, and fast bowlers tend to bowl them more often than spin bowlers, due to their longer run-up.

No ball can also be called by the umpire when bowler's feet touches the white line drawn in side ways.

Some no balls (generally high full pitched deliveries, or "beamers") are considered dangerous and unfair. If deliberate, the bowler may be suspended from bowling immediately, and the incident reported. If accidental, repetition will have additional consequences for the bowler and team. For repetition, and also for throwing, the bowler may be suspended from bowling in the game, reported, and required to undertake remedial work on his bowling action.

Fast short pitched bowling ("bouncers") may also be judged dangerous and unfair by its repetition, and it is the repetition that will at some point cause the Umpire to call No ball.

A No ball may be called for a variety of reasons. Most commonly, it is the result of a bowler breaking one of the first two rules below (a front foot No ball or back foot No ball).

Dangerous deliveries (beamers) are another common reason.

If the front foot of a bowler lands inside the crease and slides outside of the crease, then it is not a No ball. If the foot lands outside the crease, it is a No ball.

An umpire will rule a No ball under any of the following conditions:

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Wikipedia