Duckworth Lewis Stern Method Explained: How DLS Works in Cricket

If you've ever watched a rain-interrupted ODI or T20 match, you've seen the scoreboard flash a "DLS Par Score" or "Revised Target." Behind these numbers lies one of cricket's most important innovations: the Duckworth-Lewis-Stern (DLS) method.

In this guide, we'll break down exactly how the DLS method works, why it was created, and how revised targets are calculated — in plain English, with real examples.

The Problem: Why Cricket Needed DLS

Cricket is unique among major sports in that weather can drastically alter a match. When rain interrupts a limited-overs game, the teams may end up with different numbers of overs to bat. This creates a fundamental fairness problem: how do you set a fair target when one team gets fewer overs?

Before DLS, cricket used simpler (and deeply flawed) methods:

• Average Run Rate Method: Simply scaled the target by the ratio of overs. The problem? A team that scores slowly at the start and plans to accelerate later gets punished unfairly.
• Most Productive Overs Method: Used in the 1992 World Cup, this method took the best overs from Team 1's innings and set a target based on those. It led to the infamous scenario where South Africa needed 22 off 13 balls, rain came, and after the delay they needed 22 off just 1 ball.

That 1992 World Cup debacle made it clear the sport needed a better solution. Enter Frank Duckworth and Tony Lewis.

The Key Insight: Cricket Resources

The brilliant insight behind the DLS method is treating a cricket innings as having two resources:

1. Overs remaining — how many overs the batting team still has left
2. Wickets in hand — how many wickets the batting team has not yet lost

At the start of a 50-over innings, a team has 100% of its resources (50 overs, 10 wickets). As overs are bowled and wickets fall, the resources decrease. The DLS method assigns a precise percentage to every possible combination of overs remaining and wickets lost.

For example:

• 50 overs left, 0 wickets lost = 100%
• 40 overs left, 1 wicket lost = 84.2%
• 25 overs left, 5 wickets lost = 42.2%
• 10 overs left, 7 wickets lost = 17.9%

Key observation: losing early wickets depletes resources much more than losing late wickets, and the value of overs at the start of an innings (when more wickets are in hand) is greater than overs at the end.

How the DLS Calculation Works

When a match is interrupted, the DLS method compares the resources available to each team:

Step 1: Calculate Team 1's Resources

If Team 1 batted their full innings without interruption, their resources = 100% (for a 50-over match). If Team 1's innings was also shortened (e.g., rain during the first innings), their resources are calculated based on what they actually had available.

Step 2: Calculate Team 2's Resources

This is where it gets interesting. Team 2's resources account for what they've already used AND what they have remaining after the interruption. If overs are lost, the resources drop.

Step 3: Apply the Formula

The revised target depends on whether Team 2 has more or fewer resources than Team 1:

• If Team 2 has fewer resources (R2 < R1): The target is scaled down. Target = Team 1's Score × (R2/R1) + 1
• If Team 2 has more resources (R2 > R1): Runs are added to the target. Target = Team 1's Score + G50 × (R2 − R1)/100 + 1

G50 is the average first-innings score in 50-over cricket, currently set at 245 by the ICC.

A Worked Example

Let's work through a real scenario:

Mid-Innings Interruptions

The DLS method truly shines when rain interrupts during the second innings — the most complex scenario.

Standard Edition vs Professional Edition

There are actually two versions of the DLS method:

• Standard Edition: Uses a fixed resource table. Simpler to apply. Used in lower-level cricket and amateur leagues. The numbers in our DLS Calculator use this edition.
• Professional Edition: Uses a more sophisticated mathematical model that adjusts for the first innings score. Used in all international matches and major domestic tournaments (IPL, BBL, etc.). The exact formula is proprietary to the ICC.

The key difference: in the Professional Edition, the resource percentages change based on the first innings score. In a high-scoring match, the loss of overs has a greater impact on the target than in a low-scoring match.

Common Myths About DLS

Myth 1: "DLS always favours the team batting second"

Not true. DLS is mathematically neutral. The perception of bias often comes from the fact that teams batting second in shortened matches have different strategic considerations than in full matches.

Myth 2: "The par score is the target"

The par score is the score at which the match would be a tie if play is abandoned at that point. The target to WIN is par score + 1. Many broadcasts confuse these two numbers.

Myth 3: "DLS doesn't work in T20s"

DLS works in any limited-overs format. While some argue that the resource curves may not perfectly fit T20 cricket's aggressive batting style, the ICC has calibrated the Professional Edition specifically for each format.

History and Timeline

• 1992: The infamous World Cup semi-final triggers demand for a better method.
• 1997: Frank Duckworth and Tony Lewis publish their original method.
• 1999: The ICC adopts the Duckworth-Lewis method for international cricket.
• 2003: The Professional Edition is introduced for international matches.
• 2014: Professor Steven Stern takes over management. The method is renamed "DLS."
• 2024: DLS remains the standard for all ICC events and most domestic leagues worldwide.

Try the DLS Calculator

Want to calculate a DLS target yourself? Use our free Duckworth-Lewis-Stern Calculator to compute revised targets for any match scenario.