Explainers
How the Decision Review System works
Reviews let teams challenge an umpire. The technology involved is simpler than it looks.
The Decision Review System (DRS) lets a captain or batter ask for the on-field umpire’s decision to be checked by the third umpire. The number of unsuccessful reviews each team gets depends on the format and the competition’s regulations.
The tools
- Ball tracking follows the ball and predicts where it would have gone. It is mainly used for LBW decisions.
- Sound-based edge detection detects whether the ball touched the bat or glove.
- Slow-motion replay checks run-outs, stumpings and catches.
If the technology is inconclusive on a close call, the original decision stands. A team that wins a review keeps it; one that loses a review has it used up.