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เรากำลังจัดทำคู่มือการศึกษาที่ครอบคลุมสำหรับ Duckworth-Lewis-Stern Calculator กลับมาเร็วๆ นี้เพื่อดูคำอธิบายทีละขั้นตอน สูตร ตัวอย่างจริง และเคล็ดลับจากผู้เชี่ยวชาญ
The Duckworth-Lewis-Stern (DLS) method is perhaps the most mathematically sophisticated rule ever adopted in mainstream sport. In the 1992 Cricket World Cup semi-final, England needed 22 runs from 13 balls when rain stopped play against South Africa. When play resumed, the outdated 'Most Productive Overs' method revised South Africa's target to an impossible 21 runs from 1 ball — a result widely condemned as absurd and prompting a global search for something better. Statisticians Frank Duckworth and Tony Lewis answered that call in 1997, and their method was adopted by the ICC in 1999. Professor Steven Stern refined the system in 2014, lending his name to the current version. The DLS method works on a core insight: a batting team has two resources at any point in an innings — overs remaining and wickets in hand. Both deplete as the match progresses, and their combined value determines how many runs a team can be expected to score from that point. The method encodes this relationship through a mathematically derived resource table covering all combinations of overs (0–50) and wickets lost (0–9). When rain interrupts play, the method calculates the proportion of resources lost by each team and adjusts the target accordingly, ensuring the revised chase reflects equal resource availability wherever possible. DLS is used in all ICC-sanctioned limited-overs matches worldwide — ODIs and T20Is — as well as in domestic competitions across every cricket-playing nation. Match referees, umpires, and team analysts all monitor live DLS targets throughout any match where weather is possible. Broadcasters display the DLS par score in real time so fans can follow along. Critique remains. The method struggles when very high or very low scoring conditions prevail because its resource percentages were calibrated on historical average-scoring data. In matches where teams routinely score 350+, the standard tables may underestimate the value of resources, a known limitation that Stern's 2014 revision partially addressed by introducing a match-type parameter (G50) that can be calibrated to the scoring environment. Despite its complexity, DLS is the fairest rain-rule ever devised for cricket and has withstood decades of scrutiny.
DLS Target Formula: Team 2 Target = Team 1 Score × (R2 / R1) Where: R1 = Resources available to Team 1 (always 100% if no interruption) R2 = Resources available to Team 2 after all stoppages Resource% = Z(u, w) = Z_max × [1 − exp(−b(u) × u / Z_max)] where u = overs remaining, w = wickets lost Simplified Par Score formula: Par Score = Team1_Score × (Resources_Team2 / Resources_Team1) Worked Example: England score 250/5 in 50 overs (R1 = 100%) Rain reduces India's innings to 40 overs starting after 0 wickets lost Resources available to India = R2 = Z(40, 0) ≈ 89.3% of full resources Revised Target = 250 × (89.3 / 100) = 223.25 → rounded up = 224 runs in 40 overs Par score at any point during India's chase is read from the live DLS table.
- 1Before the match begins, both teams are assigned 100% of their available batting resources, representing the full combination of 50 overs and 10 wickets.
- 2When rain halts play, the official scorer or match referee calculates the resource percentage consumed or lost for the affected team using the ICC-approved DLS resource tables.
- 3If Team 1's innings is interrupted, their final score is scaled up to reflect what they would have scored with full resources, or Team 2's target is adjusted downward to reflect Team 2's reduced resources.
- 4If Team 2's innings is interrupted mid-chase, the DLS par score is consulted — if Team 2 is ahead of par when the match is abandoned, they win; if behind, they lose.
- 5The revised target is always rounded up to the next whole number to ensure Team 2 must score one more run than the par score to win outright.
- 6In T20 matches, the same DLS logic applies but uses a separate resource table calibrated for 20-over matches, reflecting the higher run-scoring environment and the premium on early wickets.
- 7Professional scorers use ICC-certified DLS software (currently administered by CricHQ) to compute live targets automatically, reducing manual calculation errors during time-pressured stoppages.
When both teams have full resources, DLS is not triggered. Pakistan needed 337 to win in a straightforward chase, ultimately losing by 89 runs.
Brief drizzle in the final did not formally trigger DLS, but the scenario illustrates how minor stoppages are monitored — any loss of overs would have recalibrated the target immediately.
Team 2 loses 10.7% of resources so the target drops proportionally. This is one of the most common DLS scenarios in everyday county and domestic cricket.
This illustrates the critical par-score mechanism: even though Team 2 had scored 180, they needed 196 at that exact point with those wickets in hand to be ahead of DLS par.
ICC match officials use DLS software in real time during all international limited-overs matches to compute revised targets the moment overs are confirmed lost.. This application is commonly used by professionals who need precise quantitative analysis to support decision-making, budgeting, and strategic planning in their respective fields
Team analysts track live DLS par scores to advise captains on whether to accelerate, consolidate, or protect wickets based on where they stand relative to par at each over.. Industry practitioners rely on this calculation to benchmark performance, compare alternatives, and ensure compliance with established standards and regulatory requirements
Broadcasters (Star Sports, Sky Sports, Willow) overlay live DLS par score graphics so television audiences can follow the match narrative during and after rain delays.. Academic researchers and students use this computation to validate theoretical models, complete coursework assignments, and develop deeper understanding of the underlying mathematical principles
Fantasy cricket platforms automatically adjust points and scoring projections when DLS is triggered, recalibrating expected totals for all remaining players in the affected match.. Financial analysts and planners incorporate this calculation into their workflow to produce accurate forecasts, evaluate risk scenarios, and present data-driven recommendations to stakeholders
When Team 1's innings is itself interrupted and they receive fewer overs, their
When Team 1's innings is itself interrupted and they receive fewer overs, their score must be scaled upward using a 'notional' full-innings score before computing Team 2's target — simply using the raw score would be unfair. When encountering this scenario in duckworth lewis stern calculations, users should verify that their input values fall within the expected range for the formula to produce meaningful results. Out-of-range inputs can lead to mathematically valid but practically meaningless outputs that do not reflect real-world conditions.
In very low-scoring conditions (scores under 100 in a 50-over match), the DLS
In very low-scoring conditions (scores under 100 in a 50-over match), the DLS target can sometimes appear to be more than Team 1 actually scored, because resources imply Team 1 under-performed given the overs available. Analysts must check whether the pitch/conditions justify a manual adjustment via the G50 parameter. This edge case frequently arises in professional applications of duckworth lewis stern where boundary conditions or extreme values are involved. Practitioners should document when this situation occurs and consider whether alternative calculation methods or adjustment factors are more appropriate for their specific use case.
Multiple rain interruptions compound: each stoppage recalculates resources
Multiple rain interruptions compound: each stoppage recalculates resources cumulatively, and the final target is derived from the net remaining resources after all interruptions. Teams can theoretically face several different DLS targets during a single innings. In the context of duckworth lewis stern, this special case requires careful interpretation because standard assumptions may not hold. Users should cross-reference results with domain expertise and consider consulting additional references or tools to validate the output under these atypical conditions.
| Overs Remaining | 0 Wickets Lost | 2 Wickets Lost | 5 Wickets Lost | 7 Wickets Lost | 9 Wickets Lost |
|---|---|---|---|---|---|
| 50 | 100.0% | 83.8% | 49.5% | 26.1% | 7.6% |
| 40 | 89.3% | 75.1% | 44.6% | 23.5% | 6.9% |
| 30 | 75.1% | 63.4% | 37.6% | 19.8% | 5.8% |
| 20 | 56.6% | 47.6% | 28.2% | 14.9% | 4.3% |
| 10 | 32.1% | 26.9% | 16.0% | 8.4% | 2.4% |
| 5 | 17.2% | 14.4% | 8.5% | 4.5% | 1.3% |
| 1 | 3.6% | 3.0% | 1.8% | 0.9% | 0.3% |
What is the DLS method in cricket?
The Duckworth-Lewis-Stern (DLS) method is a mathematical formula used to recalculate targets in rain-interrupted limited-overs cricket matches. It accounts for both overs remaining and wickets in hand to ensure fair revised targets. It replaced the flawed 'Most Productive Overs' method in 1999. In practice, this concept is central to duckworth lewis stern because it determines the core relationship between the input variables.
How is the DLS target calculated?
DLS multiplies Team 1's score by the ratio of Team 2's available resources to Team 1's available resources. Resources are percentages derived from tables that factor in wickets lost and overs remaining. The resulting target is always rounded up by one run. The process involves applying the underlying formula systematically to the given inputs. Each variable in the calculation contributes to the final result, and understanding their individual roles helps ensure accurate application.
What is DLS par score?
The DLS par score is the number of runs Team 2 must have scored by a specific point in their innings (at a given wickets-lost state) to be 'level' with Team 1's resource-adjusted score. If play is abandoned, a team ahead of par wins and a team behind par loses.
Why is DLS controversial?
Critics argue DLS can produce targets that feel counterintuitive, especially when very high or very low scores are involved. The method was calibrated on historical scoring rates, so in an era of 400-plus ODI scores, some believe resources are undervalued. Steven Stern's 2014 update addressed some of these concerns. This matters because accurate duckworth lewis stern calculations directly affect decision-making in professional and personal contexts.
Is DLS used in T20 matches?
Yes, DLS applies to all ICC-sanctioned T20I matches and most domestic T20 leagues. A separate resource table calibrated for 20-over cricket is used, which reflects the much faster scoring pace and different strategic dynamics of T20 compared to ODIs. This is an important consideration when working with duckworth lewis stern calculations in practical applications. The answer depends on the specific input values and the context in which the calculation is being applied.
What is the minimum overs requirement for DLS to apply?
In ODIs, the ICC requires a minimum of 20 overs per side for a result to stand under DLS. In T20Is, the minimum is 5 overs per side. If these minimums are not met, the match is declared a no-result or rescheduled. In practice, this concept is central to duckworth lewis stern because it determines the core relationship between the input variables.
Who administers the DLS method?
The ICC owns the intellectual rights to the DLS method and licenses its implementation to CricHQ, which develops the official DLS software used by scorers worldwide. Steven Stern of Queensland University of Technology (now Bond University) serves as the official custodian of the method's statistical framework. This is an important consideration when working with duckworth lewis stern calculations in practical applications.
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When watching a rain-interrupted match, track both the DLS target AND the par score simultaneously. The target is fixed once overs are confirmed, but the par score changes ball by ball — it's the more dynamic and tactically critical number for the chasing team's captain.
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The original Duckworth-Lewis method was first published in a statistics journal in 1997 and initially computed by hand using printed tables. Frank Duckworth kept the resource percentages in a spreadsheet on a single floppy disk, and the first official match to use it was Zimbabwe vs England in January 1997 — a match England won under the new system.