The Duckworth-Lewis-Stern (DLS) method in cricket is a mathematical formula used to fairly calculate the target score for the team batting second in limited-overs matches (such as One Day Internationals or T20s) when the game is interrupted by weather or other delays, reducing the number of overs available.

Core Principle

• The DLS method treats the batting team's resources as two main factors: overs remaining and wickets in hand. Both are considered resources that a team uses to score runs.
• At the start of an innings, a team has 100% of its resources (full overs and all 10 wickets).
• As the innings progresses, these resources are depleted-overs run out and wickets fall.
• If interruptions reduce the number of overs available, the target score is adjusted proportionally to the resources left to the batting team, ensuring fairness

How It Works

• The method calculates a "resource percentage" based on the number of overs left and wickets remaining at any point.
• This resource percentage is derived from historical data on scoring patterns and is not a simple linear relationship; it accounts for the fact that losing wickets and overs affects scoring potential exponentially.
• The revised target for the second team is calculated using the formula:

Team 2’s par score=Team 1’s score×Team 2’s resourcesTeam 1’s resources\text{Team 2's par score}=\text{Team 1's score}\times \frac{\text{Team 2's resources}}{\text{Team 1's resources}}Team 2’s par score=Team 1’s score×Team 1’s resourcesTeam 2’s resources​

• The method also considers that a team batting first might have paced their innings differently if they had known the innings would be shortened

Why DLS Is Needed

• Before DLS, rain interruptions led to unfair target adjustments based on overs lost, which did not consider wickets lost or the stage of the innings.
• The 1992 Cricket World Cup highlighted the need for a more scientific and fair method after a controversial rain-affected match.
• DLS provides a fair way to adjust targets without needing reserve days, which is important due to packed modern cricket schedules

Summary

• DLS is used only in limited-overs cricket.
• It adjusts targets based on the combination of overs and wickets left, reflecting the batting team's scoring potential.
• It ensures the team batting second has a fair chance to chase an adjusted target if the match is shortened.
• The method is continuously updated to reflect modern scoring trends, including T20 cricket dynamics

In essence, the DLS method balances the resources (overs and wickets) available to both teams to set a fair target when matches are interrupted, making it the accepted standard for rain-affected limited-overs cricket matches worldwide