We have all heard of the phrases “Illegal Bowling Action”& “Chucking” in cricket. This is one of the most confusing parts of cricket for common people just watching cricket.

Many also attribute, not bowling with a round-arm action as chucking but this is totally a misconception.

Now, this post is dedicated to all those cricket enthusiasts out there, who want to know what actually chucking is an illegal bowling action means. And also about the 15-degree allowance in the bowling action.


As in case of throwing we bend our arms when we conserve the potential energy in the hinge joint of the arms.

While we throw the ball we straighten it and release it to convert the potential energy into kinetic energy which makes the ball move faster.

As a result the arm at first bends and then releases out to straighten.

This phenomenon is not allowed when bowling.

This exercise of bending the arm while in the bowling stride and then straightening it immediately before releasing it is known as “chucking”.

Suppose a bowler has a bend at his elbow when the bowling arm reaches his shoulder level. If he delivers the ball with the same bend then it is legal. Whereas if he straightens his arm during the release of the ball then the action is illegal.

Any bowler who is suspected bowling with an illegal action, he is to be reported to ICC by either the on-field umpires or the match referee.

Then he has to undergo the bio-mechanic test procedure under an ICC specialist.

If he doesn’t bowl all the deliveries or it is found with an illegal action he/she gets banned from bowling in competitive cricket. Then he can reapply for the test after he modifies and corrects his bowling.

But with a lot, biomechanic tests and 3-dimensional analysis of a number of bowlers in the period of 1990-2003. The ICC found that all the bowlers have some amount of arm extension while releasing the ball. Most of the bowler had an extension of 10-15 degrees.

Thus ICC allowed 15 degrees of arm extension in bowling. For example, if a bowler has a bend of say 40 degrees. When the bowling arm reaches the shoulder level and when he bowls, the arm extends to 25 degrees, even when the action is legal.

If the extension exceeds the 15 degrees then it is illegal.

There also have been many exceptions to this rule. For example, R P Singh of India and Shoaib Akhtar of Pakistan had an abnormal condition of hyperextension.

It means that their arm gets extended in the backward direction as well.

As a result of which it seemed as if they had an illegal bowling action and many times reported.

Then ICC found out about this and the rule stands for an extension to forward side only.

Another example is the legendary off spinner from Sri Lanka; Mutthaih Muralidharan.

He had some orthopedic problems in his arm, as a result, it seemed to be chucking. And was repeatedly called no-ball when he bowled. But after thorough analysis and many tests, he was allowed to ball.

Thus this topic or term is very much technical in nature and needs to be well understood by many more such posts and videos.

Many common people have misunderstood the term and they need to get clarified to understand cricket to the best. We are trying our best to make it possible.

So by this, we tried to explain what exactly chucking or illegal bowling action means. Any more doubts or queries do let us know in the comments section below.


About the author

A cricket fanatic; Tanmaya Nanda is a BSc Botany (hons) student. Right from his childhood he had a great interest in writing and being a cricket fan. He has now started to write articles about cricket. He is also the co-founder of CRICK ACADEMY and one of the contributors for the blog.

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