What is an Illegal Delivery in Cricket? – RULES EXPLAINED!

Illegal deliveries can cover a range of actions by the bowler, resulting in a no-ball. The specifics on what constitutes a legal delivery are set by the Marylebone Cricket Club document, the Laws of Cricket. The International Cricket Council also have guidance for players and officials on specific bowling actions. 

Below are the most common types of illegal deliveries in cricket. 

1. Throwing (or chucking)

Throwing, also known as chucking in cricket, is when a bowler throws the ball towards the batsman. In the official laws of cricket, a throw comes from the elbow bending and releasing the ball without straightening the elbow upon follow through. 

In the Laws of Cricket, number 24, 3, states, “A ball is fairly delivered in respect to the arm if, once the bowler’s arm has reached the level of the shoulder in the delivery swing, the elbow joint is not straightened partially or completely from that point until the ball has left the hand.”

Some famous and very successful bowlers have faced scrutiny over their bowling actions that walk a tight line between legality and chucking. For example, Sri Lankan spinner Muttiah Muralitharan had a minor deformity that slightly bent his elbow when he was bowling. This led to close inspection from officials, but a slight bend in the elbow is permitted in the rules. 

Other players, such as Sri Lankan quick bowler Lasith Malinga, have a unique bowling style that appears similar to a throw at first. As a result, Malinga has faced scrutiny for chucking, as his technique leads his arm to swing out further than most bowlers. However, because his elbow is only slightly bent, he did not face any sanctions for illegal bowling.

2. 15 Degree Rule

Throwing in cricket is determined by the 15-degree rule, set and defined by the ICC. Under this rule, if a player’s elbow is bent more than 15 degrees between the horizontal motion and the time of release then the delivery is illegal.

This may seem an impossible task for umpires to verify with the naked eye. However, the officials are left to their own judgement to decide if a delivery breaks the 15-degree rule. 

If a player is deemed to bowl an illegal delivery, the following process takes place:

• An umpire submits a report.
• The player attends an ICC Accredited Testing Centre. Here they bowl in front of hi-tech equipment and experts in human movement.
• A decision is made on whether the action is legal or illegal.
• If legal, the player continues to play for their team.
• If illegal, the player is suspended and must modify their technique to rectify the 15-degree rule.

Before the 15-degree rule, the rules on elbow flexing were stricter. There was no set amount of bend, but even if players flexed their elbows slightly, they would be called. 

However, following repeat calls of Muralitharan for bending his elbow upon delivery in the 1990s, the rules became more relaxed. Originally, the ICC set different rules for different bowlers. Five degrees was allowed for spinners, 7.5 for medium pacers and 10 for quick bowlers. 

Eventually, the flex degree was set to 15. This was decided because recognising any slight variation via the naked eye was near impossible for on-field umpires. 

3. Underarm Bowling

During informal cricket games, spectators may see bowlers throw the ball towards the batsman in an underarm motion. In modern cricket, this action is never used because ‘overarm’ bowling is now the norm.

However, this has not always been the case. Until the 1910s, underarm bowling was the preferred method of bowlers. But players soon realised they could generate more pace with a longer run-up and greater momentum. Underarm bowling remained in the rules until 1981 when one incredible incident between Australia and New Zealand led to the rules changing. 

The rival teams played in a five-match series during the 1980/81 season. In the third match, there was a tense finale. New Zealand needed six runs to win from the final delivery, but Australia captain Gregg Chappel informed the bowler, Trevor Chappel, to bowl underarm and roll the ball towards the stumps.

Both umpires were informed, and Chappel rolled the ball for New Zealand batsman Brian McKechnie to block. The delivery prevented New Zealand from any chance to score the required runs. Although the delivery was legal in 1981, it was frowned upon in the cricket community and led to calls of unsportsmanlike behaviour and even cheating.

Consequently, the rules were changed after the incident. Underarm bowling is not banned in international cricket, and it can only be used if agreed by both captains before the start of the match. 

4. No Ball

In addition to chucking and underarm bowling, there are other forms of no-ball in cricket. If any of the following are noticed by the umpire, ‘No-ball’ is called. Depending on the format (ODI, Test or T20), if a bowler delivers a no-ball, they have to bowl the delivery again, and the batting side is given an additional run. In T20 and ODI cricket, the batting side also gets a free hit for a no-ball. 

Below are some of the most common illegal deliveries in cricket that lead to a no-ball decision:

• Overstepping: If the bowler’s front foot crosses the line that marks the beginning of the crease. This is the most common type of no-ball, with players regularly penalised for overstepping.
• Dangerous Delivery: Sometimes, a bowler will pitch their delivery too short, causing it to bounce around the batsman’s head. A similar rule applies if the bowler bowls a ‘beamer’, which doesn’t bounce and aims anywhere over the batsman’s waist. This is less common than a head height delivery.

More no-ball examples exist, such as the ball bouncing off the pitch, the bowler hitting the stumps before their delivery. However, in top-level international cricket and even lower-level cricket, many of these rules are rarely seen.