The Duckworth Lewis/ DLS method was introduced by statisticians Frank Duckworth and Tony Lewis. This is essential in deciding the match's winner when there are limited overs for the team batting second. It is a mathematical formula designed to calculate the scores for the second batting team when the match is interrupted by weather or any other circumstance. It was first introduced in 1996-1997 for the match between Zimbabwe and England. It was later approved in 1999 by the ICC board. Whenever there is an interruption due to unavoidable situations during a T-20 or ODI match, the DLS method is used to tabulate the results of the match.
What is the DLS (Duckworth-Lewis-Stern) Method?
Cricket is one of the most popular sports in the world. It is the sport most enjoyed after football and rugby, but when weather conditions interrupt the match, it affects the game and its results. In such situations, DLS plays a crucial role in deciding the winner. The DLS method is named after the two guys who invented it: Frank Duckworth and Tony Lewis. However, when Professor Steven Stern became the custodian of this method in November 2014, it was named the Duckworth-Lewis-Stern method.
For instance, In the recent IPL 2023 final, rain interrupted the match between CSK (Chennai Super Kings) and GT ( Gujarat Titans). In the first batting, GT had made 214 runs for four wickets in 20 overs. Due to the rain interruption, CSK was given a target of 171 runs to be completed in 15 overs. The powerplay was reduced to 4 overs. This is when the DLS method is used to decide the winner of the match.
When a match gets interrupted by rain, the teams do not get the full quota of overs. ICC has developed a formula to calculate the results considering the favourable parameters for both teams. In Cricket, this DLS method shall reflect the efforts of both teams.
Importance of the DLS method
Just like any other game, there are interruptions in Cricket as well. Since there are religious followers for this sport, there has to be an optimum system for such interruptions. Earlier, there was a standard edition, the Duckworth-Lewis method, which is still used in several club competitions. According to the G50 concept, if a match gets interrupted after 30 overs and the score is 180 runs, the average score would equal the net run rate* 50 overs. This makes about 300 runs. By this process, the teams might unduly benefit as G50 is based upon run rate representing the batting side. Currently, G50 is fixed for 245. It is meant to be used when computers are not available. However, this method is now not used in international Cricket.
It was found in 2003 that the standard edition needed to be better suited for runs scored. Later, the DL method was introduced in 2003 through a computerized professional to incorporate fairness in the game. Steven Stern then redefined it to make it a presentable DLS method. The DLS method was used in all matches with uncertain situations to get the results, as reserving the game for limited overs is impossible. The DLS method is accurate in delivering the results. Also, the DLS method is updated periodically by ICC for the rapidly changing conditions in the game. The DLS method optimizes the fairness attached to the game.
How does the DLS method work?
In the DLS formula, the method calculates the number of runs the team would have scores if both had equal resources. The following is the formula used by the DLS method in Cricket.
To understand its mathematical formulation,
Team 2’s par score = Team 1’s score ✕ ( Team 2’s resources / Team 1’s resources)
These resources for the respective team are obtained from computer programs. The inclination and depletion are not constant throughout the innings; if wickets are lost, the resources are consumed faster, and more balls are destroyed.
The resource values are taken from a computer program for the international cricket game. The Duckworth Lewis calculator considers the possibility of how much the team could have scored if there had been no interruption. However, the weightage of wickets and overs is still unpredictable, as it is impossible to estimate every individual's batting skill. This applies to the DLS calculator for T20 matches as well.
There are many instances where the DLS method was applied:
- In an ODI series of India vs. Pakistan in 2006, India completed its first batting and made 328 runs, whereas Pakistan had scored 311/7, and the game was stopped in the 47th over due to insufficient lighting. The DLS method was applied, and Pakistan won the match by seven runs.
- In another ODI series of Sri Lanka vs England in 2014, Sri Lanka batted first and scored 6/1 from 2 overs when the game got interrupted by rain. Once the game restarted, it was reduced to 35 overs. Sri Lanka scored 242/8, but by applying the DL method, England's target was reduced by six runs and set for 236. The DL method made things fairer for both teams.
DLS method Calculation
During the beginning of the ODI, the batting side team shall possess two resources, i.e. ten wickets and 300 balls. As the inning begins, there is depletion in the resources, and it eventually reaches zero when all the wickets are gone, and the 300 deliveries are played out. When rain is interrupted, the batting side loses deliveries, and their resources are unused. Through the DLS method, proportional help is available to each team.
The depletion rate of resources is not constant throughout the overs and varies according to the scoring pattern. The resources that are wasted due to interruption depend upon the following:
- Number of overs completed
- The innings stage at lost overs
- Number of wickets left at the time of interruption
IN CRICKET, the DLS method addresses both overs and wickets that remain at the time of interruption. It calculates the outcomes based on the availability of resources.
There can be no universally perfect weightage to predict the accurate score of the team when there is no interruption because the abilities of individuals vary, which cannot make an accurate qualitative measurement. Therefore, it is necessary to have methods like DLS to decide the game's results. Though the DLS method in Cricket has its critics, it is still the preferred method by ICC and is used in most matches. We agree this option is better, as it has made fairer decisions since its introduction.
It is an attempt to set a fair target for the innings of the second team. It is a fair and accurate method used to get results for interrupted cricket matches.
It was enacted to decide the IPL 2023 finals between Chennai Super Kings and Gujarath Titans, where the game was interrupted by rain.
- How did CSK win using the DLS method?
The rain had curtailed the target for CSK, where CSK had to score 171 runs in 15 overs. With the last two balls, CSK had to score ten runs. There was a sixer followed by four runs, which brought victory for the CSK team.