Rain has decided more cricket matches than any captain would like, and when a limited-overs game is cut short, someone has to work out a fair new target. That job belongs to the Duckworth-Lewis-Stern method – usually shortened to DLS – a mathematical formula that resets the score a chasing team needs to win. It can look baffling on the scoreboard, so this guide explains, in plain English, what DLS is, how it works and why it decides so many rain-affected results.
What is the Duckworth-Lewis-Stern method?
The Duckworth-Lewis-Stern method is a calculation used in limited-overs cricket – One-Day Internationals (ODIs) and Twenty20 (T20) matches – to set a fair revised target when rain or another delay shortens the game. It is the official system approved by the International Cricket Council (ICC), the sport’s world governing body.
The core problem it solves is simple: if a chasing team suddenly has fewer overs to bat, you cannot just scale the target down by overs alone, because a side with all ten wickets in hand can score far faster than one that is nearly all out. DLS values both the overs a team has left and the wickets it still has, then works out a target that reflects what each side really had to work with.
Key Facts
| Full name | Duckworth-Lewis-Stern method (DLS) |
|---|---|
| Purpose | Sets a fair revised target in rain-shortened limited-overs cricket |
| Created by | Frank Duckworth and Tony Lewis (English statisticians) |
| First used | 1 January 1997 (Zimbabwe v England ODI) |
| Adopted by the ICC | 1999 |
| Renamed DLS | 2014, after Steven Stern became custodian |
| Used in | One-Day Internationals and Twenty20 cricket |
| Minimum overs for a result | 20 per side (ODI); 5 to the side batting second (T20I) |
| Governing body | International Cricket Council (ICC) |
Why cricket needs a rain rule
Before DLS, rain-hit matches used crude fixes. The best-known failure came at the 1992 World Cup semi-final between South Africa and England. With South Africa closing in on a gettable target, a short rain break under the old “most productive overs” rule left them, when play resumed, needing an impossible number of runs off the final ball – a result almost everyone agreed was unfair.
Two English statisticians, Frank Duckworth and Tony Lewis, built a fairer model based on how teams actually score across an innings. It was first used in international cricket on 1 January 1997, in a Zimbabwe versus England ODI, and the ICC adopted it as its standard method in 1999.
In 2014 the statistician Steven Stern became the method’s custodian and updated it to reflect modern, higher-scoring cricket, especially the fast run rates of T20; his name was then added and the system became the Duckworth-Lewis-Stern method. Tony Lewis died in 2020 and Frank Duckworth in 2024, but the method they created still carries all three names.
How DLS works: resources, par and target
DLS treats every batting side as having two “resources” at any moment: the overs it still has to face, and the wickets it still has in hand. A team starting a full 50-over ODI innings with all ten wickets has 100% of its resources. As overs are used and wickets fall, that figure drops. Every possible combination of overs left and wickets down maps to a resource percentage, read from a pre-calculated table.
Par score versus target
Two terms cause most of the confusion. The par score is the total a chasing side should have reached at a given moment to be level with the first team, given the resources used so far; it changes as wickets fall. The target is the score needed to actually win – the par figure plus one run. If a team finishes exactly on par, the match is a tie.
The formula in plain terms
Write Team 1’s score as S, the resource percentage Team 1 had as R1, and the resource percentage Team 2 has as R2. There are three cases:
- R2 equals R1: both sides had the same resources, so the target is simply S + 1.
- R2 is less than R1: the chasing side has fewer resources, so the target is scaled down in proportion – par = S × (R2 ÷ R1), then rounded down and one run added.
- R2 is greater than R1: the chasing side has more resources (for example, if Team 1’s innings was the one cut short). The Standard Edition adds the extra runs those resources are worth, using a figure called G50 – the average score expected from a full 50-over innings, set at 245 for top-level men’s cricket. The target becomes S + (R2 − R1) × G50 ÷ 100 + 1.
A simple worked example
Imagine Team 1 bats its full 50 overs and posts 250 (so R1 = 100%). Rain then cuts Team 2’s innings, and the DLS table shows they have, say, 85% of the resources Team 1 had. Because R2 is less than R1, par is 250 × (85 ÷ 100) = 212.5, so the score needed to win is 213. The actual resource percentage always comes from the official DLS table, but the arithmetic is as plain as that.
Minimum overs and “no result”
DLS can only decide a match once enough cricket has been played. For a 50-over game, each side must face at least 20 overs; for a T20 international, at least five overs must be bowled to the side batting second. If rain prevents a match from reaching that minimum, it is declared a no result. The exceptions are the obvious ones – a side that is bowled out, or a chasing team that passes its target early, produces a result regardless.
Standard versus Professional editions
There are two versions of the method. The Standard Edition uses a single published table of resource percentages and can be worked out by hand, which makes it suitable for club and lower-level cricket and as a backup if a computer fails; it is the version that uses the G50 figure. The Professional Edition adjusts the resource percentages according to the first team’s total as well, so it needs the ICC’s official software to run. It copes far better with very high scores and has replaced the Standard Edition at professional level since 2003.
Is the DLS method fair?
No rain rule can be perfect, but DLS is widely accepted as the fairest practical system, precisely because it is built on how thousands of real innings have actually unfolded rather than on a single crude ratio. Its main criticisms are that a revised target can feel harsh after multiple interruptions, and that the maths cannot read a team’s batting plan on the day. The Stern update specifically improved its accuracy in the high-scoring games that exposed the older model, which is why it remains the global standard.
What DLS means for Kiwi cricket bettors
For anyone following the scoreboard with a wager in mind, the key point is that the official DLS result is the one that counts. When rain revises a target, match-winner markets are normally settled on that DLS outcome, not on the original score. Some markets – such as total match runs or a player’s projected total – may be voided if the shortened game no longer fits the bet, so it is always worth checking an operator’s own rules.
If you are new to the wider topic, our guide to cricket betting covers the main formats and markets, while the explainers on sports betting odds and decimal odds show how a price turns into a potential return. For the bigger picture, see how how sports betting works in New Zealand under current law.
Responsible gambling
This article explains a cricket rule for general information only. It is not betting advice and does not encourage anyone to gamble. Betting carries financial risk, and no formula or strategy can guarantee a winning outcome. You must be 18 or over to bet on sport or racing in New Zealand. If gambling is causing harm for you or someone you know, free and confidential help is available from the Gambling Helpline Aotearoa on 0800 654 655, and from the Problem Gambling Foundation of New Zealand. Gambling in New Zealand is regulated by the Department of Internal Affairs.
Sources
- International Cricket Council – Ten years at the top for Duckworth-Lewis (first use, 1 January 1997)
- International Cricket Council – ICC expresses sadness at death of DLS method founder Tony Lewis
- International Cricket Council – Cricket mourns loss of Frank Duckworth
- International Cricket Council – Duckworth-Lewis-Stern methodology (Stern Edition, G50)
- England and Wales Cricket Board – Duckworth/Lewis/Stern Methodology (Standard Edition, pre-October 2003)
- International Cricket Council – Men’s T20I Match Clause 13: Innings (minimum overs)
- SportsCafe – Powerplay in cricket: P1, P2 and P3 explained
- Omni Calculator – Duckworth-Lewis method calculator and explanation
- YouthLaw Aotearoa – Gambling (minimum age to bet at the TAB)
- Gambling Helpline Aotearoa – 0800 654 655
- Department of Internal Affairs – Gambling in New Zealand
Frequently asked questions
What is P1, P2 and P3 in cricket?
P1, P2 and P3 are not DLS terms at all. They are a common shorthand for the three powerplay phases of a one-day international innings – the mandatory powerplay (overs 1-10), the middle phase (overs 11-40) and the final phase (overs 41-50), each with different fielding restrictions. The DLS calculation instead uses resource percentages, written R1 and R2 in the formula above.
Does the DLS method apply to T20 cricket?
Yes. The same resources-and-wickets logic is used in T20 as in 50-over cricket; only the scale differs. In a T20 international, at least five overs must be bowled to the side batting second for DLS to produce a valid result.
Can a DLS target be higher than the original score?
It can. If the team batting first was the one interrupted, the chasing side may end up with more resources, so the method adds expected extra runs and the revised target can be above the first team’s actual total.
What happens to my bet if a cricket match is a no result?
If rain stops play before the minimum overs are bowled, the match is a no result, and most sportsbooks then void match-winner bets and refund the stake because there is no official outcome to settle on. When a DLS result is reached instead, match-winner bets stand on that revised result. Either way, side markets that no longer fit the shortened game can still be voided, so check the operator’s settlement rules.
