DLS Calculator – Duckworth Lewis Stern Revised Target & Par Score

What Is the Duckworth-Lewis-Stern (DLS) Method?

The Duckworth-Lewis-Stern method is a mathematical system used to reset targets in interrupted limited-overs cricket. When rain or another interruption removes playing time, the second team may no longer have the same batting opportunity that existed when the match began. DLS attempts to make the revised target reflect the scoring resources still available to each side.

The important idea is that batting opportunity is not represented by overs alone. A team with many overs remaining and several wickets in hand has more scoring resources than a team with the same number of overs remaining but many wickets already lost. The DLS framework therefore combines overs remaining and wickets lost into a resource percentage.

The ICC describes DLS as the method used to recalculate targets when limited-overs matches are interrupted. The methodology expresses resources as percentages of the resources available in a complete 50-over innings.

Why Does Cricket Need DLS?

A simple run-rate method would treat every over as if it had the same value. That is not realistic. Early in an innings, a batting side may have all ten wickets available and a large number of overs in which to build an innings. Near the end, the same number of overs can represent a very different scoring opportunity depending on how many wickets remain.

For example, losing five overs when a team has ten wickets in hand is not necessarily equivalent to losing five overs when that team has already lost seven wickets. DLS accounts for this difference by using a pre-calculated resource table.

The purpose is therefore not simply to “take away runs for lost overs.” It is to compare the relative resources available to the two teams and then set a target that reflects that comparison.

How DLS Resources Are Measured

For a table-based calculation, the resource percentage is read from the combination of overs remaining and wickets lost. The table values are percentages of a full 50-over innings resource.

Overs remaining

More overs remaining generally means more scoring opportunity. As an innings moves from 50 overs remaining toward the end, the remaining resource percentage decreases.

Wickets lost

More wickets lost generally means less scoring resource. The resource table therefore gives a lower percentage for the same number of overs remaining when more wickets have already fallen.

Why a 20-over innings does not start at 100%

The table is normalized to a complete 50-over innings. A shorter scheduled innings starts with only part of those 50-over resources. This is why a 20-over starting resource is below 100% even before any wicket is lost. The DLS methodology also applies the resource framework to matches with fewer than 50 overs per innings; in that case, the starting resource is below 100% of a complete 50-over innings.

How to Determine R1 and R2 From an Interruption

The target calculator requires R1 and R2 as the final resources available to Team 1 and Team 2. In a real interrupted match, these percentages can be built from the resource table by looking at the innings before and after an interruption.

1. Record the overs remaining and wickets lost immediately before the suspension.
2. Use the resource table to find the resources remaining at the start of the suspension.
3. Record the overs remaining and wickets lost when play resumes.
4. Use the table again to find the resources remaining after the interruption.
5. Subtract the post-interruption resource from the pre-interruption resource to determine the resource lost.
6. Subtract the resource lost from the resources available when that innings started. The result is the resources available for the innings.

DLS Revised Target Formula

The published Standard Edition uses different calculations depending on whether Team 2 has fewer, equal, or greater resources than Team 1. The target is rounded down to a whole number before the one run required to win is added.

When R2 is less than R1

This is the most common “downward revision” situation. Team 2 has less batting resource available, so the target is reduced in proportion to the resource ratio.

When R2 equals R1

If both sides have equal resources, there is no resource-based adjustment. Team 2 simply needs one more run than Team 1’s score.

When R2 is greater than R1

When Team 2 has more resources available, the Standard Edition increases the target using the excess resource and the competition’s applicable G50 value, representing the average 50-over total used by the method. The Standard Edition regulations specify G50 values by class of game; for the full-member/first-class category used here, the value is 245.

Worked DLS Example: Team 2 Has Fewer Resources

Worked DLS Example: Team 2 Has Equal Resources

This is the familiar situation in an uninterrupted 50-over match where both innings receive the same full resource allocation.

Worked DLS Example: Team 2 Has More Resources

This example demonstrates why the G50 input matters when Team 2 has more resources. It is not used in the downward-revision or equal-resource cases.

How to Use the DLS Calculator

1. Enter Team 1’s final score in runs.
2. Enter R1, the resources available to Team 1.
3. Enter R2, the resources available to Team 2.
4. Keep G50 at the applicable value for the relevant Standard Edition competition, or change it when the competition rules require another value.
5. Click Calculate DLS Target.
6. Review the revised target, par score, resource ratio and step-by-step calculation.

For a resource lookup, select the whole number of overs remaining and wickets lost, then click Find Resource %. The lookup is useful when manually building the resource inputs required by the target calculation.

How the DLS Resource Lookup Works

The lookup is a direct table read. For example, with 35 overs remaining and no wickets lost, the published whole-over table gives 82.7% resources. With 35 overs remaining and three wickets lost, the resource value is lower because the batting side has less wicket resource available.

The resource percentage is not a prediction of the number of runs a team will score. It is a measure of the remaining scoring opportunity used by the DLS methodology to compare interrupted innings.

Five Practical Sections for Rain-Affected Cricket

Rain calculations have two separate layers. First, match officials determine the revised playing allocation when playing time is lost. Then DLS uses the resulting overs and wickets to calculate resource loss, a revised target or a par score. The five sections below separate those jobs so the user does not confuse an overs reduction with a DLS target calculation.

Section 1: How Are Overs Deducted After Rain?

The revised-overs decision is made from the available playing time under the competition’s playing conditions; DLS itself does not simply decide how many minutes of rain occurred. For current ICC men’s ODIs, the revised number of overs is based on a rate of 14.28 overs per hour of remaining playing time. For men’s T20Is, the corresponding rate is 14.11 overs per hour. The playing conditions also account for intervals, interruptions, extensions and permitted extra time.

This is deliberately labelled an estimate. The official calculation can be more involved because the match clock and competition-specific playing conditions determine the total playing time available. Once the umpires announce the revised overs, those official overs should be entered into Scenarios 1–4.

Scenario 1: First Innings Complete, Rain Before the Second Innings

In this situation Team 1 has completed its innings and produced an actual score. Rain then delays Team 2 and the number of overs available to Team 2 is reduced. Team 1’s resource percentage is based on the resources it was allocated for its completed innings, while Team 2’s resource percentage is taken from the resource table for its new reduced allocation.

For example, if a 45-over match has Team 1 scoring 212 in its full 45 overs and rain reduces Team 2 to 35 overs, the Standard Edition table gives the two sides different starting resource percentages. The target is then calculated from the ratio of Team 2’s available resources to Team 1’s resources. This is the classic “delay to the start of Team 2’s innings” situation described in the published methodology.

Scenario 2: Second Innings Has Started, Then Rain Interrupts the Chase

Here Team 2 already has a score and has lost some wickets when rain stops play. The calculation is more involved because DLS must measure the resource lost during the suspension rather than simply looking at the new number of overs.

First, find the resource percentage remaining immediately before the interruption using the overs left and wickets lost. Next, find the resource percentage remaining after the revised overs are set, using the same wickets lost. The difference between these two resource values is the resource lost because of the suspension. That loss is deducted from Team 2’s starting resources to produce the new R2.

The revised target is then recalculated from Team 1’s score and the new R1/R2 relationship. If the match is abandoned at that point, the current Team 2 score is compared with the resulting par score. A score equal to par is a tie; a score above par means Team 2 is ahead under the applicable result procedure; a score below par means Team 1 is ahead.

Scenario 3: Match Has Not Started, Rain Reduces the Overs

If no ball has been bowled when rain reduces the match, there is no Team 1 score to revise. Both teams simply receive the new shortened allocation. The resource table gives the starting resource percentage for that reduced number of overs with no wickets lost.

For an educational Standard Edition estimate, the shortened-match starting resource can be expressed against G50 to produce an expected starting par/target benchmark. This is fundamentally different from Scenarios 1 and 2 because there is no actual first-innings score and therefore no conventional “revised target” based on S.

Scenario 4: Second Innings Partially Completed, Rain Ends the Match

This is the abandonment/result situation. Team 1 has a completed score, Team 2 has batted for part of its innings, and play cannot resume. DLS first determines Team 2’s resource position at the moment of abandonment. For the Standard Edition, when an innings is terminated, the resource remaining at suspension is treated as the resource lost; the remaining resource after termination is zero.

The resulting R2 is compared with R1 to calculate the DLS par score. The winning target is one run above par, but when the match is abandoned the actual Team 2 score is compared directly with par: above par means Team 2 wins, equal to par means the match is tied, and below par means Team 1 wins, subject to the minimum-overs and result provisions of the applicable playing conditions.

DLS and T20 Cricket

DLS can be applied to limited-overs formats shorter than 50 overs. The important point is that the resource table is normalized to a 50-over innings, so a shorter scheduled innings does not begin with 100% of the 50-over resource.

For example, a T20 innings has a lower starting resource than a full 50-over innings because it contains fewer overs. If an interruption then removes part of those 20 overs, the available resource is reduced further.

This calculator can help explain the resource concept and perform Standard Edition-style calculations when appropriate resource percentages are known. It should not be treated as an official T20 match calculator because competition playing conditions and the current authorized DLS implementation determine the official target.

DLS and ODI Cricket

In an uninterrupted 50-over ODI, both teams normally begin with the same full resource allocation. If the first innings is completed normally and the second innings also receives its full allocation, R1 and R2 are equal and no resource adjustment is needed.

Rain or another interruption can change the resource balance. If Team 2 receives fewer resources than Team 1, the target is reduced. If Team 2 receives more resources than Team 1, the Standard Edition upward-adjustment formula can increase the target.

Under ICC playing conditions, revised targets are calculated using the applicable DLS method, with the target expressed as a whole number for the relevant result procedure.

What Is the DLS Par Score?

The par score is the benchmark score corresponding to the state of the chase at a particular point in time. In the simple target calculation used here, the winning target is one run above the calculated par score.

During an interrupted chase, the par score can be used to determine whether the chasing side is ahead, level or behind at the point of suspension under the applicable playing conditions. The applicable playing conditions use this comparison between the team’s score and the DLS par score.

It is important not to confuse a par score with a forecast of the final score. Par is a DLS benchmark based on the resources available at that moment.

Why Wickets Matter in DLS

DLS treats wickets as a resource because a batting side with wickets in hand can generally take greater scoring risks. Losing wickets reduces the side’s remaining scoring potential even when the number of overs left is unchanged.

This is why DLS does not use a single “runs per over” correction. The same number of overs remaining can correspond to different resource percentages depending on wickets lost. The resource table is designed to capture that interaction between time and wickets.

Standard Edition vs DLS Professional

Standard Edition

The Standard Edition is the table-based form of the methodology and can be operated manually using published resource percentages. It is useful for understanding the underlying resource concept and for backup/manual calculations.

DLS Professional

The professional implementation is computer-based and is the authorized system used for official high-level cricket. The Professional Edition was introduced to improve the handling of situations where the older manual approach could produce less satisfactory adjustments, including unusually high-scoring matches.

The official ICC DLS resources provide the methodology and Standard Edition table, while current playing conditions refer to the applicable DLS method for official matches.

Common DLS Calculation Mistakes to Avoid

• Reducing the target directly by lost overs: DLS is resource-based, not a simple proportional-overs calculation.
• Ignoring wickets: Wickets lost change the resource percentage even when overs remaining are identical.
• Treating every innings as 100% at the start: A scheduled innings shorter than 50 overs starts with less than 100% of the 50-over resource.
• Using the wrong G50: The applicable G50 depends on the class of game under the Standard Edition rules.
• Assuming the whole-over table is ball-by-ball exact: Mid-over states can require finer resource values.
• Calling a Standard Edition result an official ICC Professional result: The official calculation can use the current authorized DLS implementation and competition-specific conditions.

Limitations and Accuracy

This calculator is designed to make the DLS resource concept understandable and to perform transparent Standard Edition-style calculations. It is intentionally not presented as official match-official software.

• Target calculations depend on the R1 and R2 resource percentages entered by the user.
• The built-in lookup uses whole-over resource rows rather than the complete ball-by-ball table.
• Multiple interruptions may require several resource-loss calculations before R1 or R2 is known.
• Competition rules can determine which DLS implementation, parameters and procedures apply.
• The editable G50 field should be set according to the applicable Standard Edition class of game when the upward-adjustment formula is used.
• Official international matches should use the current authorized DLS system and the applicable playing conditions.

Frequently Asked Questions

References and Data Sources

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