Cricket Bowling Action — Legal Actions, Throwing & ICC Testing Explained
A legal cricket bowling action requires the elbow not to straighten (extend) by more than 15 degrees at the point of delivery. Learn how the ICC tests bowlers, famous throwing controversies, and what makes a bowling action illegal.
A **bowling action** is the physical mechanics a bowler uses to deliver the ball. Cricket is unique among bat-and-ball sports in requiring the ball to be delivered with a **straight arm** — the elbow cannot straighten (extend) during the bowling action. An action that violates this rule is called a **throw** or **chuck**, and it is illegal.
What Makes a Bowling Action Legal?
Under Law 24, a ball is unfairly delivered if the bowler's arm straightens (extends at the elbow) by more than the allowable margin at the point of delivery. Since 2004, the ICC has standardised the permitted degree of elbow extension to **15 degrees** — applicable to all bowlers worldwide.
| Elbow Extension | Status | Note |
|---|---|---|
| 0–15 degrees | Legal | All bowling styles permitted within this range |
| More than 15 degrees | Illegal (throw) | Bowler reported to ICC for testing |
| N/A (wrist spinners) | Legal | Wrist position does not affect elbow rule |
Why 15 Degrees? The History
Before 2004, the permitted degree of elbow flexion varied by bowling style (fast, medium, slow). This created inconsistency — off-spin bowlers were allowed more elbow bend than pace bowlers. Research by the ICC's biomechanics panel found that almost all human elbows naturally straighten slightly during fast arm movements, so a zero-tolerance rule would ban many legitimate actions. The **15-degree threshold** was chosen to allow for natural hyperextension while still prohibiting deliberate throwing.
The ICC Testing Process
- An on-field umpire reports a suspect bowling action to the Match Referee.
- The bowler is referred to an **ICC Accredited Testing Centre** (typically at a university biomechanics lab).
- Testing uses high-speed cameras and motion capture to measure elbow extension in degrees across all delivery types.
- If found illegal, the bowler **cannot bowl internationally** until they remodel their action and pass a retest.
- Some bowlers (particularly spin bowlers with unorthodox grips) have multiple delivery types — each is tested separately.
Famous Bowling Action Controversies
- **Muttiah Muralitharan (Sri Lanka):** The most controversial case in history. Murali was no-balled for throwing by Australian umpires in 1995–96. ICC testing consistently showed his elbow did not extend beyond the allowed range — his unusual wrist and shoulder anatomy made his action appear illegal on TV but was legal under measurement. He took 800 Test wickets and remained fully legal.
- **Saeed Ajmal (Pakistan):** Reported in 2014; all deliveries (off-spin, doosra, teesra) found to exceed 15 degrees. Remodelled action and returned; never regained his pre-ban effectiveness.
- **Shoaib Akhtar (Pakistan):** Reported multiple times for his fast bowling action; cleared after testing. Often bowled at 100 mph, making any elbow movement extremely hard to detect visually.
Frequently asked questions
What happens if a ball is bowled with an illegal action in a match?
The umpire may call a no-ball immediately if the action is obviously illegal, but in practice, umpires only report actions post-match. Play proceeds normally on the day; the penalty (suspension from bowling) follows after ICC testing.
Can a bowler bowl if they have been reported for a suspect action?
Yes, until officially suspended by the ICC. Being 'reported' triggers a testing process but does not immediately ban the bowler from playing or bowling.
Does the 15-degree rule apply to wrist spin (leg-spin, googly)?
Yes. The 15-degree elbow extension rule applies to all bowlers regardless of style. Wrist spin bowlers tend to pass more easily because their wrist action, not elbow action, generates spin.