What is the Duckworth Lewis Method and how is it applied in Cricket?

The Duckworth-Lewis-Stern or DLS method (which is now known) is a mathematical system used to compute target scores and reach outcomes in limited-overs contests that have been curtailed due to rain. It was created and named after English statisticians Frank Duckworth and Tony Lewis, and it was first used in 1997. Steve Stern, an Australian scholar, modified the algorithm and became its curator before the 2015 World Cup; his name was added to the title.

Let us know what is duckworth lewis method is and what duckworth lewis method completely means by and how does duckworth lewis method work in detail from this article.

Why is the Duckworth Lewis Rule needed?

It would seem ideal to have a reserve day in place for a limited-overs contest and resume play the next morning, but logistical and scheduling challenges mean that this is not always possible. As a result, the game's administration have long struggled to determine the most fair method of resolving rain-affected one-dayers. When a match is stopped due to the bad weather and one or both teams do not receive their full quota of overs, a decision has to be made in the time available when play resumes. Any calculation attempts to adjust a target score in response to the reduction in overs.

Any number is an estimate; there is no one-size-fits-all answer. The ICC has tried to develop a model that takes into account as many variables as possible while accurately reflecting both sides' efforts. The DLS method, which has been updated several times, is largely viewed as the most accurate in international cricket.

Why were older methods discarded?

Average Run Rate (ARR) was used to calculate targets when ODI cricket was first played. In this case, the chasing team is only required to match the opponent's run rate. If Team A scored 200 in 50 overs at a run rate of 4, and Team B's innings were cut to 30 overs, the total to beat would be 120. However, this strategy did not account for lost wickets or the fact that maintaining a good run rate over a smaller number of overs was easier.

So, if Team A batted first and made 200 in 50 overs, and Team B was 100 for nine in 20 overs when rain stopped play, the latter would be declared the winner. As a result, the ARR approach was inherently biased in favour of the side batting second.

Prior to the 1992 Cricket World Cup, Australia developed the Most Productive Overs (MPO) method as an alternative to the ARR. The target was reduced by the number of runs scored by a team in its least productive overs, which was equal to the number of overs lost. If Team A scored 250 runs in 50 overs and Team B's innings was cut to 30 overs, the total to beat would be the total number of runs scored by Team A in its highest-scoring 30 overs.

Here, Team B had a genuine cause because the best 20 overs sent down by its bowlers were ignored. For the sake of argument, if Team B bowled 20 maiden overs and gave up 250 runs in the remaining 30 overs, its 30-over target would still be 251. As a result, Team B received a penalty for bowling too many low-scoring overs. Clearly, this method favoured the team that batted first.

Its flaws were famously exposed during the semi-final match between England and South Africa in the 1992 World Cup. South Africa was 231 for six and needed 22 off 13 balls when play was delayed for 12 minutes due to rain. Two overs were lost, and the two lowest-scoring overs in the England innings — totalling one run — were struck off. As a result, the target was only decreased by one run, and South Africa only had one ball to score 21 runs (the scoreboard incorrectly flashed 22 that day). The absurdity of the game's conclusion motivated the hunt for a better method.

Years later, in an interview with the BBC, Duckworth said that the incident had inspired him to come up with a solution. “I recall hearing cricket journalist Christopher Martin-Jenkins on the radio say ‘surely someone, somewhere could come up with something better,' and I quickly realised it was a mathematical problem that required a mathematical solution,” he added.

How does the Duckworth Lewis method work?

Let us discuss how Duckworth lewis law or Duckworth lewis method work here.

Every team has two types of resources available, according to the technique.

These two resources are;

1. Remaining over

2. Remaining wickets

These two resources are used at all times during the game.

Frank Duckworth and Tony Lewis have created a chart based upon two resources that show how many resources are left with the batting side in certain situations.

By seeing the chart, it is clear that, when a team has all 50 overs and all 10 wickets before the game starts, it is said to have 100% resources.

After then, when the team's overs and wickets are used up, the team's resources are finite as the game goes.

When a team has played 20 overs and lost two wickets in a match, they are left with just 30 overs and eight wickets. The squad is left with only 67.3 percent resources, according to Duckworth-Lewis.

(Image Will be Uploaded Soon)

Now, if the rains come at this point and the match is rained out, the batting team is left with just 20 overs and has already lost two wickets; according to the Duckworth-Lewis technique, the batting team only has 52.4 percent resources in hand.

(Image Will be Uploaded Soon)

So the rain has wiped away 67.3 – 52.4 = 14.9 of the batting side's resources.

As previously stated, the team batting first had spent all of its resources, whereas the team batting second only had 100 - 14.9 = 85.10 resources.

In other words, 14.9 percent of the second team's resources have been washed away in the rain.

However, this explanation appears to be biased because the first team has spent 100% of its resources, and the second team, or batting second team, has just 85.10 resources. To establish a level playing field, both teams should have equal resources. The Duckworth Lewis law or Duckworth lewis method will reduce the target set by the batting first side in this situation.

According to the Duckworth Lewis method, if rain affects the second team's inning, the aim should be changed. As a result, the first team's goal will be lowered.

If the team batting first is affected by the rain, the target will be increased, meaning the team would have to chase more runs.

Example of Duckworth lewis system

Let us look at the Duckworth lewis system in detail with an example.

If the rain affects the team that bats later or plays the second inning, the following steps must be taken: -

Assume the first team scored 300 runs in 50 overs, whereas the second team scored 250/4 in 40. If the match cannot be played after this, the Duckworth Lewis law or Duckworth lewis method will be used to determine a winner.

The first team played all 50 overs, which indicates they spent all of their resources. The second team had 100 percent resources at the start of the inning as well, but the rain stopped them from using them. The second team has 10 overs and 6 wickets after 40 overs.

According to the Duckworth Lewis rule table, the second batting team is left with 26.1 percent of the resources in this case. Assume the match is called off from this point forward.

There is now a disparity in the resources accessible to both teams. As we know, the first team used all of its resources, whereas the second team only used 100-26.1= 73.9 percent.

(Image Will be Uploaded Soon)

The match's winner will now be decided by an equal distribution of resources across both teams.

Because the second team has limited resources than the first, the aim for the second team must be reduced.

Because the first team scored 300 runs, the second team's aim will be 300 x 73.9 / 100 = 221.7.

So, according to the rules, the second team must score 222 runs to win a game, but it has already scored 250.

As a result, the second team will be declared the winner with a score of 250 - 222=28 runs.