What Is the Duckworth-Lewis-Stern Method?
The Duckworth-Lewis-Stern method — universally abbreviated to DLS, and sometimes still referred to as D/L or Duckworth-Lewis — is the internationally recognised formula used to recalculate target scores in limited-overs cricket matches interrupted by rain, bad light, or other unavoidable delays.
When a rain interruption reduces the number of overs available to one or both teams, simply scaling the target proportionally by overs would produce unfair results. A team chasing 250 in 50 overs, reduced to 25 overs after a stoppage, cannot simply be asked to score 125 — because in the original innings, the batting team would have been batting far more aggressively in the final 25 overs, with wickets in hand and a clear run rate target. Asking the chasing team to score at a steady run rate across 25 overs ignores the reality that the final phase of a 50-over innings is the most productive.
DLS solves this by accounting for both dimensions of batting resource simultaneously: overs remaining and wickets remaining. The method was developed by statisticians Frank Duckworth and Tony Lewis, adopted by the ICC in 1997, and updated in 2014 by Steve Stern — which is why the full name now includes his surname.
The Two Resources: Overs and Wickets
The fundamental insight behind DLS is that a batting team’s scoring potential is determined by two resources, not one:
1. Overs remaining — the more overs a team has left, the more runs they can score. Obvious enough.
2. Wickets remaining — the more wickets a team has in hand, the more aggressively they can bat. A team on 100/0 with 10 overs left can score far more freely than a team on 100/8 with 10 overs left, even though both have the same overs.
These two resources interact. A team that has lost many wickets cannot fully exploit the overs they have remaining, because each delivery carries the risk of ending the innings. A team with all wickets intact can take risks on every ball.
DLS quantifies exactly how much combined batting resource a team has at any point, expressed as a percentage. A full 50-over innings with all 10 wickets intact represents 100% resource. As overs are used and wickets fall, the remaining resource percentage decreases.
How the Target Is Calculated: The Principle
The DLS calculation uses a resource table — a published set of percentage values for every combination of overs remaining and wickets lost. The precise mathematical form is an exponential decay function, but the table values are what matter in practice.
The target adjustment works like this:
If the team batting second has fewer overs than the team batting first:
- Calculate the resource percentage available to Team 1 for their actual innings (usually 100% if they batted a full uninterrupted innings)
- Calculate the resource percentage available to Team 2 given their reduced overs
- Set the target proportionally: Target = Team 1’s score × (Team 2’s resource % ÷ Team 1’s resource %)
If Team 1’s innings was also interrupted:
The calculation is more complex because both teams have had their resources reduced. The method compares the resource percentage lost by each team and adjusts the target accordingly.
A Worked Example: Simple Rain Interruption
Match: England vs Australia, ODI at Lord’s
England bat first, score 280 in 50 overs with no interruption to their innings.
Rain falls before Australia begin their chase. The match is reduced to 30 overs per side.
Australia’s resource for a 30-over innings with all 10 wickets = approximately 75.1% (from the DLS resource table) England’s resource for a full 50-over innings = 100%
DLS target = 280 × (75.1 ÷ 100) = 210.3 → rounded to 211
Australia need 211 from 30 overs to win, or 210 to tie (a Super Over if the competition rules apply). The 30-over target is not simply 280 × (30/50) = 168 — that would ignore the fact that in the last 20 overs of their innings, England would have been batting more aggressively. The DLS target of 211 is higher than the naive proportional calculation because those final overs are high-value batting resource.
A Worked Example: Mid-Chase Interruption
This is the more common betting-relevant scenario: Australia are chasing and rain interrupts during their innings.
England score: 280 from 50 overs Australia’s chase before rain: 80/2 from 20 overs Overs lost to rain: 10 overs. The match resumes with Australia having 20 overs remaining (not 30), still 80/2.
Now two resource calculations are needed:
Australia’s resource at start of chase: 100% (full innings) Resource used before rain: overs faced (20) + 2 wickets lost = resource consumed so far Resource remaining after rain: resource for 20 overs remaining with 8 wickets = approximately 52.4%
Total resource available to Australia = resource used before rain + resource remaining after rain
Compare this to England’s 100% resource.
If Australia’s total available resource is, say, 79% of England’s, the target is set at 280 × 79% = 221. Australia need 221 from their total overs (the 20 played plus 20 remaining = 40 overs total available at match start, effectively).
The exact calculation requires the official DLS software, which match officials use in real time. The principle — comparing the resource percentage available to each team and adjusting the target accordingly — is what matters for understanding DLS and its implications.
When DLS Increases the Target
A common misconception is that DLS always reduces the target when overs are lost. In fact, DLS can increase the adjusted target beyond the straight-line score if the interruption occurs at a particularly expensive point in the chasing team’s innings.
Scenario: Team 2 are chasing 250. After 10 overs, they are 80/0 — well ahead of the run rate. Rain interrupts and 15 overs are lost.
The 80 runs at 10 overs represents high scoring relative to the resource used (10 overs with all wickets). The resource remaining — 25 overs with all 10 wickets — is valuable. But the resource lost (15 overs that would have been played at full batting potential) was also significant.
In some versions of this scenario, particularly when the interruption removes overs from the middle of a innings during which the batting team was scoring very freely, the DLS calculation can set a revised target that is higher than the score the chasing team was on track for. The chasing team is “penalised” for having scored so freely early, because the model recognises those overs were used when batting resource was plentiful.
This counterintuitive outcome has caused controversy in high-profile matches — most notably the 1992 Cricket World Cup semi-final between England and South Africa, which used a predecessor method (not DLS) and produced the infamous situation where South Africa needed 21 runs off 1 ball. DLS was developed specifically to prevent outcomes like that.
DLS vs. Its Predecessors
Before DLS, various less sophisticated methods were used, all of which had significant flaws:
Run Rate method: Simply adjusted the target by the ratio of overs available. Completely ignored wickets remaining, making it easily exploitable by teams that had scored freely early while retaining wickets.
Most Productive Overs (MPO) method: Used the highest-scoring overs from the first innings to calculate what the team batting second had “lost.” Systematically biased toward the team batting second because the first team’s best overs were typically their final overs — meaning the chasing team got credit for the most productive part of the first innings being removed.
Average Run Rate method: A simplistic calculation that ignored both the distribution of scoring across overs and wickets remaining.
DLS replaced all of these and is universally recognised as the most statistically sound method available. Its 2014 update (incorporating Steve Stern’s refinements) improved accuracy particularly in high-scoring T20 matches, where the original D/L tables slightly underestimated first-innings par scores at extreme totals.
DLS in Different Formats
ODIs (One-Day Internationals — 50 overs)
DLS was originally designed for ODI cricket and works most cleanly in this format. Interruptions that reduce a 50-over match to a minimum of 20 overs per side typically produce well-calibrated revised targets. Most ODI competitions require a minimum of 20 overs for a result; if fewer overs are possible, the match is abandoned.
T20 Internationals and T20 Leagues (20 overs)
DLS applies in T20 formats but requires the most careful reading of its outputs. T20 cricket’s inherently high-scoring nature — particularly in modern franchise competitions with small grounds and flat pitches — means small numbers of overs lost can create significant target revisions. The minimum overs required for a DLS result in T20 is typically 5 overs per side (ICC minimum for T20Is), though competition-specific rules vary.
T20 DLS targets are more frequently disputed than ODI ones because the shorter format amplifies the impact of any single over being lost from the calculation.
List A and Domestic Competitions
Domestic competitions (The Hundred, Vitality Blast, county one-day competitions) apply DLS under their specific competition rules. The Hundred uses a modified format (100 balls per side rather than overs) but applies DLS principles adapted for the ball-count structure. Always check the specific competition rules for how rain targets are calculated.
DLS and Betting: What You Need to Know
Rain-affected matches create specific and important betting considerations. Getting this wrong before a bet is placed is one of the most avoidable sources of unexpected settlement outcomes in cricket betting.
How Bookmakers Settle Rain-Affected ODI and T20 Bets
Different bookmakers apply different rules for rain-affected match settlement. The key distinctions:
Full match bets (match winner): Most bookmakers settle on the official result including DLS-adjusted outcomes. If a team wins via DLS, they win the bet. If the match is abandoned without a result, most bookmakers void the bet and return stakes. A reduced match that produces a DLS result typically stands.
Minimum overs clauses: Many bookmakers require a minimum number of overs to be bowled for match winner bets to stand. Common minimums are 20 overs per side (ODI) or 5 overs per side (T20), though this varies. If the match does not reach the minimum, the bet is voided. Always check your bookmaker’s specific minimum overs clause before placing.
In-play bets: If rain interrupts a match mid-innings and your in-play bet was placed during the first innings, the settlement depends on whether the match reaches the minimum for a result. If it does not, your in-play bet is typically voided. If it does, the DLS result stands.
Player performance markets (top scorer, man of the match, over/under runs scored): These markets often have specific rules for rain-affected matches. Top batter markets may settle on the most runs scored in the available overs, or may be voided if fewer than a specified number of overs are bowled. Check the market-specific terms.
The Par Score Concept: Betting In-Play
Professional cricket bettors and broadcasters use the concept of a DLS par score when assessing whether a chasing team is on track during a match that might be interrupted.
The par score is the DLS target at any given point in a chase — the exact score the chasing team would need if rain were to fall at that moment. If the chasing team is above par, they are winning on DLS. If they are below par, the fielding team is winning on DLS.
During live broadcasts of ODI and T20 matches, the par score is typically displayed on screen alongside the chasing team’s current score. This is the most practically useful application of DLS for in-play betting — knowing whether a team is ahead or behind the DLS line tells you which team holds the advantage if rain intervenes.
Example: England are chasing 270 and are currently 140/2 from 28 overs. The DLS par score at this point is, say, 133. England are 7 ahead of par. If rain falls now, England win. This information is directly relevant to in-play market pricing.
Situations Where DLS Creates Betting Value
Certain DLS scenarios create exploitable information gaps in the in-play market:
A powerplay wicket glut for the chasing team: If the chasing team loses three or four wickets in the first 10 overs, their DLS resource has been significantly depleted — a rain interruption would now produce a much lower par score for them to hit than if they had preserved wickets. The market may not instantly price in the DLS implication alongside the immediate match state.
A very high first innings score: When the first team scores significantly above the DLS “par” for their resource (posting 320 in 50 overs when average is 260), the chasing team’s target under DLS remains very high even after overs are reduced. Rain actually helps the fielding team in this scenario — a reduced target is still a high number.
Weather forecasts with rain expected mid-chase: If rain is forecast 20–25 overs into a 50-over chase, knowing whether the chasing team is likely to be above or below DLS par at that point shapes which team benefits from the interruption. Professional bettors monitor weather forecasts and par scores simultaneously.
Frequently Asked Questions
What is the minimum for a DLS result in cricket?
In ODI cricket, ICC rules require a minimum of 20 overs per side for a result. In T20Is, the minimum is 5 overs per side. Domestic competition rules vary — check the specific competition’s playing conditions.
Can DLS make a target higher than the original score?
Yes, in specific circumstances. If the team batting second is chasing aggressively and scoring well above the DLS par when rain falls, the revised target after overs are lost can exceed the original par trajectory. The target is adjusted based on the resources available to each team, not simply downward proportionally.
Why was the method renamed Duckworth-Lewis-Stern?
Steve Stern updated the mathematical formula in 2014, principally to improve accuracy in very high-scoring T20 and ODI matches. The ICC renamed the method to acknowledge his contribution. The underlying principle and resource table structure remain as originally designed by Frank Duckworth and Tony Lewis.
Does DLS apply in Test cricket?
No. Test cricket is not limited-overs cricket — the format does not impose a fixed number of overs on each innings, so there is no scoring resource to recalculate. Rained-off time in Tests simply results in overs being lost from the match, potentially causing a draw that would otherwise have produced a result.
Is DLS perfectly fair?
DLS is the most accurate method available and is universally applied at international level. It is not perfect — no formula can perfectly replicate what a batting innings would have looked like without interruption. Criticism tends to focus on extreme high-scoring T20 matches, where the resource table’s assumptions about average scoring rates underweight the batting conditions at certain venues. The 2014 update to the Stern variant addressed much of this, but edge cases remain.
Sources: ICC playing conditions; Duckworth-Lewis-Stern official documentation; ESPN Cricinfo.