Cricket Stumps and Bails — Rules and Specifications

Cricket stumps and bails form the wicket — the target that bowlers aim at and the structure that defines several dismissal types including bowled, stumped, run out, and hit wicket. The Laws of Cricket precisely specify stump and bail dimensions, and the question of whether bails have been 'dislodged' is central to many of the game's most dramatic dismissal decisions.

Stump Dimensions

Each wicket consists of three wooden stumps — the off stump, middle stump, and leg stump. Law 8 of the Laws of Cricket specifies that stumps must be 28 inches (71.1 cm) in height above the playing surface. The combined width of the three stumps and the gaps between them must not exceed 9 inches (22.86 cm). Stumps are typically made from willow or ash wood.

The Bails

Two wooden bails sit in grooves on top of the stumps. The Laws specify that the overall length of each bail must not exceed 4.375 inches (11.1 cm). Bails must rest in the grooves on top of the stumps — they should be balanced lightly enough to fall off on impact but securely enough not to be dislodged by wind or vibration. The groove-and-bail system is what makes it possible for the ball to clip the bail off without necessarily displacing the stumps.

What Constitutes 'Breaking the Wicket'

A wicket is considered 'put down' (broken) when a bail is completely removed from the top of the stumps, or when a stump is struck out of the ground. Simply making contact with the stumps without removing a bail does not constitute a dismissal. This has led to controversial incidents — notably when a fast delivery hits the stumps but the bails fail to fall due to a snug fit, and no wicket is given.

LED Bails and Zing Bails

Modern cricket has seen the introduction of LED-illuminated 'Zing bails' at the top level of the game, including Test cricket. These bails contain circuit boards that light up when the bail is dislodged — providing a clear visual indicator for umpires and third umpires making run-out and stumping decisions. LED bails must meet the same dimensional specifications as traditional bails.

Stumping and Run-Out Dismissals

In both stumpings and run-outs, the wicket must be broken while the batsman is out of their crease (grounded behind the popping crease). The wicketkeeper must hold the ball when breaking the wicket for a stumping; in a run-out, any fielder may break the wicket either directly or after a catch. Third umpires routinely review slow-motion replays to determine if the bail has been completely dislodged before the bat or body is grounded.