The Duckworth-Lewis method in cricket is a mathematical formula used to set a fair revised target when rain or another interruption shortens a limited-overs match. Its core idea is simple: a batting side has two resources, the overs it can face and the wickets it has in hand, and when weather steals some of those overs, the target is recalculated in proportion to the resources each team actually had. That is why a side chasing in a rain-hit game rarely just has its target cut by the same fraction as the overs. This explainer from newsreverse com breaks down how the method works, why cricket needed it, and how it became the Duckworth-Lewis-Stern, or DLS, method used around the world today.
Why does cricket need the Duckworth-Lewis method at all?
Limited-overs cricket has a scheduling problem that timed formats do not: both teams are supposed to get the same number of overs, but rain does not respect the fixture list. Before a proper formula existed, officials used crude fixes that regularly produced absurd outcomes. The most notorious was the “most productive overs” approach used at the 1992 World Cup, where South Africa, needing a gettable 22 runs off 13 balls against England, returned after a rain break to find the target had become 22 off a single ball, an impossible ask that had nothing to do with fairness. Methods like average run rate were no better, because they ignored the crucial fact that wickets in hand are as valuable as overs remaining. A team with all ten wickets can attack far more freely than one that is seven down. Cricket needed a method that accounted for both. That is exactly what two English statisticians, Frank Duckworth and Tony Lewis, set out to build.
How does the Duckworth-Lewis method actually work?
The method rests on the concept of resources. At the start of an innings a team has 100 percent of its resources: all its overs and all ten wickets. As the innings goes on, those resources deplete. Every over bowled uses some up, and every wicket lost uses up more. Published resource tables give the percentage remaining for any combination of overs left and wickets down. When an interruption changes how many overs a team can face, you compare the resources each side had available and scale the target accordingly.
In its simplest published form, the revised target for the team batting second is calculated as:
- Revised Target = (Team 1 score x Team 2 resources / Team 1 resources) + 1
If the team batting second has fewer resources than the first team enjoyed, its par score is scaled down; if it somehow has more, the target is scaled up. The full official calculation uses detailed resource tables and is more involved than this one line, but the principle is exactly that: targets track the resources available, not just the raw number of overs.
A simple worked example
Imagine Team 1 bats a full 50 overs and scores 250. That innings used 100 percent of its resources. Rain then delays the chase, and Team 2 is cut to 40 overs from the start, so it never had a full innings. Suppose the resource tables say Team 2 has only 85 percent of resources available for its shortened innings. Applying the formula, the revised target becomes roughly 250 x 85 / 100, which is about 212, plus one run, so 213 to win off 40 overs. Note what has happened: Team 2’s target of 213 is lower than 250, but the runs required per over, about 5.3, is actually higher than Team 1’s original 5.0. That reflects reality. A team batting only 40 overs can take more risks than one pacing itself over 50, so the method asks it to score a little faster in return for a lower total. This is the sort of adjustment that pure run-rate maths would get badly wrong.
What changed when it became DLS?
The method was introduced internationally in the late 1990s and quickly became the standard. But cricket kept evolving, and by the 2000s scores in one-day internationals were climbing steeply, with totals well beyond 300 becoming common. The original model had been tuned to an era of lower scoring, and it did not always cope well with very high totals. In 2014 an Australian academic, Professor Steven Stern, revised the formula to better reflect modern batting, and the method was renamed the Duckworth-Lewis-Stern method, or DLS. It remains the version officially recognised by the International Cricket Council and used in professional cricket worldwide. The name honours all three statisticians whose work shaped it.
When is a DLS result possible?
Rain does not automatically produce a DLS result. A minimum amount of play is required so that the shortened contest is still meaningful. The exact thresholds are set by the playing conditions for each competition, but the widely used minimums are shown below.
| Format | Minimum overs per side for a result | Governing document |
|---|---|---|
| One Day International | Generally 20 overs each | ICC / tournament playing conditions |
| T20 International | Generally 5 overs each | ICC / tournament playing conditions |
If the weather prevents even these minimums, the match is usually declared a no-result rather than being decided by DLS. Individual tournaments can and do set their own precise rules, so the figures above are the common standard rather than a universal law; the official playing conditions for a given series are always the definitive reference.
How do you read the DLS par score during a chase?
If you watch a rain-threatened chase, you will often see a “par score” or “DLS par” figure on the broadcast graphic. This is one of the most useful things a fan can understand, because it tells you, at any moment, whether the batting side is ahead of or behind where the method says it should be. The par score is the total the chasing team should have reached, for the number of overs bowled and wickets lost so far, to be exactly level on resources. If the batting side is above par when rain ends the game, it wins; if it is below par, it loses; if it is exactly level, the result can be a tie. This matters in practice because a team batting second in bad weather is not only chasing the eventual target but also constantly managing its position against par, in case the rain returns and ends the innings early. A captain who knows a storm is closing in may push for quick runs to stay ahead of par, accepting the risk of losing wickets, precisely because the DLS par line, not the final target, could decide the match. Reading that line turns a tense, weather-hit finish into something you can follow with real understanding.
What are the criticisms of the method?
No system for rain-affected cricket pleases everyone, and DLS has its critics. Fans sometimes find the revised targets counterintuitive, especially when a chasing side is asked to score at a rate that feels punishing. The method also assumes teams would have batted in a broadly typical way, which cannot capture a specific match situation, such as a side deliberately holding wickets back for a planned late assault that rain then cuts short. Some argue it can slightly favour the team batting second in certain scenarios, while others make the opposite case. What is not in serious dispute is that DLS is far fairer and more consistent than the ad hoc methods it replaced, and that it handles the central truth those older methods ignored, that overs and wickets together define a team’s true position. It is a model, and like any model it is an approximation, but it is a well-tested and transparent one.
Why the method still matters
For Indian fans in particular, who follow cricket across the monsoon-affected subcontinent and beyond, DLS is a familiar presence. Rain-interrupted games in the IPL, in bilateral series and at World Cups are routinely settled by it, and a “par score” flashed on screen during a chase is the method quietly at work, telling you whether the batting side is ahead or behind where DLS says it should be. Knowing the logic turns a confusing scoreboard adjustment into something you can follow ball by ball. The essential idea is worth carrying with you: the target moves with the resources, the overs available and the wickets in hand, so that a shortened game still produces a result both teams can accept as fair.
It is also useful to know that broadcasters and scorers do not calculate DLS by hand in the middle of a match. Official software approved by the governing bodies holds the full resource tables and computes revised targets and par scores instantly, which is why the numbers appear on screen the moment rain stops play. That standardisation is part of the method’s strength: the same tables and the same program are applied everywhere, so two identical match situations produce the same target regardless of the venue or the officials involved.
Cricket is full of rules that reward a closer look, from playing conditions to the mechanics of a result. If you enjoy understanding the systems behind the sport, you can find more clear, sourced explainers in our sports section, where we break down the numbers, laws and decisions that shape the games India loves to watch.