What is Duckworth-Lewis-Stern or DLS Method in cricket? Explained

The DLS method was devised to bring more genuine outcomes in a limited overmatch affected by rain. The rule was officially adopted by ICC in 1999.

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The Duckworth-Lewis-Stern or popularly known as the DLS method is a mathematical calculation to calculate target scores when the rain interrupts the match.

The DLS method was devised by English statisticians Frank Duckworth and Tony Lewis, and named after them. The DLS method was first used in 1997. Later in 2015, before the ICC World Cup, Australian academic Steve Stern updated the formula, and then Stern's name was also added to the title.

Why did DLS come into existence?

The journey of the DLS method was as interesting as the rule itself is. When we dive deeper into the past, we get to know that as soon as ODI cricket began, the Average Run Rate or ARR method was there. The calculation of the Average Run Rate was simple and based on the run rate. But then soon players realise that it is more beneficial for the team second and hence should be replaced by something more important.

Hence, the ARR rule is replaced by the Most Productive Overs. In this rule, the batting second team target is not decided based on the overall run rate of the team batted first but according to the specific run rate of overs where the former team scored the most runs.

But this rule favours the team bowling second and hence couldn't rely much on it. When all these rules failed to provide a better alternative, the DLS method came into existence.

When was the DLS method first used?

The DLS method is a brainchild of the gem of Frank Duckworth and Tony Lewis, who was trying to give a better alternative for cricket matches affected by rain. Officially, the DLS method was first used in a match between Zimbabwe and England on January 1, 1997. Later, this rule was officially adopted by ICC's calculation method for rain-affected games in 1999.

How does the DLS method work?

The DLS method addresses both overs and wickets remaining as a resource and revises the target based on the availability of the resources.

The rate at which resources depletes is not constant throughout the inning, as the resources consume faster if the wickets are lost, and more balls are consumed.

The DLS method decides the target or outcomes by calculating the runs scored by both teams if the resources available to both sides were equal. To express it in simple terms, Team 2’s par score = Team 1’s score x (Team 2’s resources/Team 1’s resources). In international cricket, the resource values (which are not publicly available) are obtained from a computer programme.

The best thing about the DLS method is that it also considers the fact that the team batting first would have batted differently if they had known the game was going to be truncated.