Duckworth-Lewis-Stern Method: The Full Explanation With Examples
A complete explainer on the Duckworth-Lewis-Stern (DLS) method in cricket — why it exists, how it works, common misconceptions, and worked examples from famous matches.
Why Does the DLS Method Exist?
In limited-overs cricket, rain or other interruptions frequently reduce the number of overs available in an innings. When overs are lost, the chasing team faces a different target than the team that batted first — the DLS method recalculates the target to account fairly for the overs lost. Before DLS, methods like 'run rate' adjustments produced absurd results in famous cases, most notably South Africa's infamous World Cup 1992 rain interruption that left them needing 22 runs off 1 ball.
The Core Concept: Resources
DLS (originally Duckworth-Lewis, now Duckworth-Lewis-Stern after mathematician Steve Stern updated the formula) works on the concept that a batting team has two 'resources': overs remaining and wickets in hand. When overs are lost due to rain, the batting team loses overs — hence resources. The DLS table assigns a percentage resource value to every combination of overs remaining and wickets in hand. The system calculates how many resources each team had available and adjusts the target accordingly.
Simple DLS Example
Team A scores 250 in 50 overs. Rain interrupts between innings; Team B now has only 40 overs. DLS calculates Team B has approximately 90% of the resources Team A had (40 overs, all 10 wickets vs 50 overs, all 10 wickets). The revised target = 250 × (Team B's resources / Team A's resources) = 250 × (90.3% / 100%) ≈ 226. Team B need 226 to win in 40 overs.
When Rain Interrupts the Chase
DLS also handles rain during the second innings — the more complex scenario. If Team B are batting and rain stops play when they have scored 150 in 30 overs with 6 wickets down, and the game cannot resume, the DLS par score is calculated for that point in the innings. If Team B's score exceeds the DLS par at that moment, they win; if not, they lose. This is why a team chasing might actually win via DLS even without completing the full required score.
Common DLS Misconceptions
- DLS doesn't punish aggressive batting in the early overs — but a team that loses wickets early and then faces rain is significantly disadvantaged because lost wickets reduce the resource percentage.
- The formula is not simply run-rate-based — it accounts for wickets, making it more sophisticated than 'how many runs do you need per over'.
- DLS par scores change ball by ball — meaning a batting team can go from winning to losing DLS within an over if they don't score.
Frequently asked questions
Why is it called Duckworth-Lewis-Stern?
The method was originally developed by statisticians Frank Duckworth and Tony Lewis. In 2014, mathematician Steven Stern took over maintaining and updating the formula, adding his name to the method.
Does DLS always produce a fair result?
The DLS method is mathematically the fairest rain interruption system ever devised for cricket, but it cannot be perfect in all scenarios. Critics argue it can produce counterintuitive results when rain falls at very specific match moments, particularly in the first 10 overs of a 50-over chase.