The Duckworth-Lewis-Stern (DLS) method is a mathematical formulation designed to calculate the target score for the team batting second in a limited overs cricket match interrupted by weather or other circumstances. The method was devised by two English statisticians, Frank Duckworth and Tony Lewis, and was formerly known as the Duckworth-Lewis method (D/L) . It was introduced in 1997 and adopted officially by the International Cricket Council (ICC) in 1999. After the retirements of Duckworth and Lewis, Steven Stern became the custodian of the method, and it was renamed to its current title in November 2014.
The DLS method attempts to calculate a statistically fair target, which has the same difficulty as the original target. It looks at the two resources available to both teams – overs and wickets. The Duckworth-Lewis algorithm adjusts the run target in proportion to these resources. At the start of the match, each team has 50 overs and 10 wickets. We say that both teams have 100 percent of the resources that they need to use to score as many runs as possible. A delay, early finish, or interruption will reduce a teams resources and mean they no longer have the same resources available. To calculate a fair target for Team 2 to achieve, the Duckworth-Lewis method uses a specific equation.
The DLS method is used when the rain interrupts the match, and it says that if the rain affects the inning of the second team, then the target should be modified. The method is the invention of statistician Frank Duckworth and Tony Lewis, and it was first used in international cricket in 1996-97 between a Zimbabwe-England match. This method was approved by the ICC in 1999. The DLS method has been implemented several times in cricket, and the most recent instance of DLS being employed to determine a rationalized score in a major cricket game happened during the IPL 2023 final between Chennai Super Kings and Gujarat Titans.
