Duckworth–Lewis–Stern method facts for kids
The Duckworth-Lewis-Stern (DLS) method is a special rule used in cricket games that have a limited number of overs. It helps make the game fair when bad weather, like rain, stops play and shortens the match. Imagine one team bats for a certain number of overs, but then rain stops the game. When play restarts, the second team might have fewer overs to bat. The DLS method then recalculates the target score for the second team, so they have a fair chance to win, even with less time.
The DLS formula also looks at how many batters are out (called 'wickets lost') when it figures out the new scores. This is important because a team with more wickets still available has more "resources" to score runs quickly.
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What is the DLS Method?
The DLS method is a mathematical formula used in limited overs cricket matches. These are games where each team bats for a set number of overs, like 50 overs in a One Day International (ODI) or 20 overs in a Twenty20 (T20) match. The main goal of DLS is to make sure that if a game is interrupted and shortened, the target score for the second team to win is fair.
Why is DLS Needed?
Cricket matches can be long, and sometimes things like rain or bad light stop play. If a game is shortened, it can be unfair for the team batting second. For example, if Team A scores 250 runs in 50 overs, but then rain means Team B only gets to bat for 25 overs, it wouldn't be fair for Team B to still need 251 runs to win. They have half the time!
The DLS method solves this problem by adjusting the target score. It makes sure that the difficulty of the task for both teams is similar, even if the game length changes.
How Does DLS Work?
The DLS method works by looking at the "resources" a team has to score runs. These resources are:
- Overs remaining: The number of overs a team still has to bat.
- Wickets remaining: The number of batters who are not yet out.
A team with more overs and more wickets has more potential to score runs. When a game is shortened, the DLS method calculates how much of their "resources" each team used or had available. It then sets a new target score for the second team that reflects the change in resources.
For example, if the first team batted for 50 overs and scored 250 runs, but the second team can only bat for 25 overs, the DLS method will lower the target score for the second team. The exact calculation is complex, but it ensures that the second team isn't trying to score the same number of runs in much less time.
Who Invented DLS?
The method was created by two English statisticians, Frank Duckworth and Tony Lewis. It was first used in international cricket in 1999. Later, another statistician, Steven Stern, helped to refine the method, which is why it's now called Duckworth-Lewis-Stern (DLS).
Images for kids
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A rain delay at The Oval, England
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Scoreboard at Trent Bridge indicating that bad light has stopped play.
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D/L began in one-day internationals
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A published table of resource remaining percentages, for all combinations of wickets lost and whole overs left
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DuckworthLewisDiag2
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DuckworthLewisDiag3
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Scoreboard showing ball-by-ball D/L Par Score.
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Many stadium scoreboards do not carry information about par scores during games
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