History of the Duckworth-Lewis-Stern Method in Cricket
How rain-affected limited-overs matches came to be settled by the Duckworth-Lewis-Stern method: its origins, the idea of resources, and its criticisms.
Rain has always been the great disruptor of cricket. In Test matches, lost time often leads to a draw, but in limited-overs games a result is expected, so a fair way of adjusting the target when play is interrupted is essential. The Duckworth-Lewis-Stern method, commonly shortened to DLS, is the system that cricket settled on, and its history shows how much thought went into a problem that looks simple.
The problem before DLS
In the early years of one-day cricket, interruptions were handled with rough measures. One approach, the average run rate method, simply scaled the target according to the overs available, which ignored how many wickets a side had in hand. Another, known as the most productive overs method, removed the least productive overs from the first innings total, which often favoured the team batting second.
The weaknesses of these methods were exposed at the 1992 World Cup semi-final in Sydney between England and South Africa. After a rain delay, South Africa’s target was recalculated under the most productive overs rule and the equation was reduced to an impossible demand from a single ball. The outcry made it clear that the game needed something better.
Two statisticians and one idea
Frank Duckworth and Tony Lewis, two British statisticians, developed an alternative built on the concept of resources. The central point is that a batting side has two resources to use, namely the overs left to face and the wickets it still has in hand. Together these determine how many runs a team can be expected to score from any point in an innings.
When a match is shortened, the method works out the percentage of resources each team had available and adjusts the target in proportion. A side that is well placed with plenty of wickets in hand loses less when overs are cut than a side that has already lost several batters.
Adoption
The Duckworth-Lewis method was first used in international cricket in 1997, in a one-day match between Zimbabwe and England, and the International Cricket Council adopted it as the standard method for interrupted limited-overs matches in 1999. It soon became familiar to supporters worldwide, and it was also taken up in domestic competitions and in Twenty20 cricket.
From Duckworth-Lewis to DLS
Over time, scoring patterns changed. Totals grew larger and batters became more aggressive, particularly in the closing overs, so the underlying tables needed adjusting. A professional edition of the method, which relied on a computer to reflect the way a match had unfolded, was used in top-level cricket.
In 2014 Professor Steven Stern, an Australian statistician, took over stewardship of the system from the original pair, and the name was updated to Duckworth-Lewis-Stern. His work refined the way the model reflects modern high-scoring cricket.
Criticisms
DLS has never been free of debate. Some critics argue that it still favours the side batting second, or that it does not always capture the importance of a strong start in an innings. Others note that the sums are hard for spectators to follow, even when the resource idea is understood. Because the calculation involves a table or software rather than a simple formula, results can feel opaque.
Defenders point out that every method has trade-offs and that DLS is far fairer than the systems it replaced. The fact that it has remained the accepted standard for more than two decades is itself a sign of broad acceptance.
Why it matters
For a team chasing a revised target, the useful lesson is that wickets in hand are as valuable as overs. A side that preserves its wickets can attack late on, and DLS recognises that. Understanding the method helps supporters make sense of the sometimes surprising targets that appear on the scoreboard after a rain break.
Frequently asked questions
What does DLS stand for?
DLS stands for Duckworth-Lewis-Stern, named after the statisticians Frank Duckworth and Tony Lewis and later steward Professor Steven Stern.
What are the resources in the DLS method?
The two resources are the overs a team still has to face and the wickets it has in hand. Together they estimate how many runs the side can still be expected to score.
When did the ICC adopt the method?
The International Cricket Council adopted the Duckworth-Lewis method as the standard way of setting revised targets in 1999, after its first international use in 1997.