The DLS method explained simply
When rain or bad light cuts overs from a limited-overs match, the DLS method sets a fair new target. It looks complicated on television, but the idea fits on one page, and you can work out a club match by hand.
By the Manage Cricket team · Updated
Contents
Why a simple run rate is not fair
Suppose a team scores 160 in 20 overs and rain leaves the chasing side only 15 overs. Scaling by overs gives a target of 121. That sounds fair until you remember that the chasing side still has all ten wickets for just 15 overs, so it can attack from the first ball. The run-rate method favours the side batting second when its innings is shortened, and it ignores wickets completely.
The method devised by Frank Duckworth and Tony Lewis, and later developed by Steven Stern (hence Duckworth-Lewis-Stern, or DLS), fixes this by counting both of a batting side's resources: the overs left and the wickets in hand.
Resources: overs and wickets together
A full 50-over innings with no wickets down is 100% of the resources. The DLS table gives the percentage still left for every combination of overs remaining and wickets lost. Fewer overs or more wickets down means a smaller percentage, and losing wickets late in an innings costs less than losing them early.
Shorter matches use the same table and simply start lower: a T20 innings starts with 56.6% and a T10 innings with 32.1% of a 50-over innings' resources. Here are the values used in the examples below, from the Standard Edition table:
| Overs left | 0 wickets lost | 2 wickets lost |
|---|---|---|
| 20 | 56.6% | 52.4% |
| 15 | 45.2% | 42.6% |
| 12 | 37.6% | 35.8% |
| 8 | 26.4% | 25.5% |
The rule in one line
Call the first side's resources R1 and the second side's R2. When the side batting second has fewer resources (the usual case after rain), its target is the first side's score scaled down: target = score × R2 ÷ R1, rounded down, plus 1. The number before adding 1 is the par score: finish level with it and the match is a tie, beat it and you win.
A worked club T20 example
Team A bats its full 20 overs and makes 160 for 6. R1 = 56.6%.
Rain falls in the break and Team B's innings is cut to 15 overs. R2 = 45.2% (15 overs, no wickets lost).
160 × 45.2 ÷ 56.6 = 127.77, rounded down to 127. That is the par score.
Team B needs 128 to win in 15 overs, not 121 as a run rate would say.
Team B, chasing 161 in 20 overs, is 70 for 2 after 8 overs when rain stops play. It has 12 overs left: 35.8%.
Four overs are lost. When play restarts Team B has 8 overs left with 2 wickets down: 25.5%.
The rain cost Team B 35.8 - 25.5 = 10.3%, so R2 = 56.6 - 10.3 = 46.3%.
160 × 46.3 ÷ 56.6 = 130.88. Par 130, target 131 in 16 overs: 61 more from the last 8 overs.
Team B used 56.6 - 35.8 = 20.8% before the rain.
Par score: 160 × 20.8 ÷ 56.6 = 58.80, rounded down to 58.
Team B is 70, ahead of par, so it wins by 12 runs on DLS, provided at least 5 overs of the chase were bowled, the usual minimum for a result in a T20.
Notice that Team B's wickets matter: had it been 70 for 6 at the stoppage, far less of its resources would have been left, and the par score would have been much higher.
When the first innings is cut short
Sometimes the side batting first loses overs and the side batting second does not. Then R2 is bigger than R1, and scaling would be unfair the other way, because the first side had no warning to accelerate. The Standard Edition instead adds runs: target = score + G50 × (R2 - R1) ÷ 100, rounded down, plus 1. G50 is the average score in a full 50-over innings: the Standard Edition rules use 245 for international and first-class teams and 200 for lower levels of the game, which is the sensible choice for club cricket.
Standard Edition and Professional Edition
There are two versions of the method. The Standard Edition is the published table you can read and use with a calculator, and the ICC keeps it as the fallback whenever the computer program is not available. The Professional Edition is a computer program used in international and top professional matches. It is not published as a table, and in high-scoring matches its targets can differ from the Standard Edition's.
For club and tournament cricket the Standard Edition is the practical choice: anyone can check the numbers. Just agree before the season which edition, which G50 and what minimum number of overs make a match, and write it into your tournament rules.
Tips for the scorer on a rainy day
- Write down the exact score, overs and wickets at the moment play stops. DLS needs the wickets as well as the runs.
- Note how many overs are lost when the umpires restart, and for which side.
- Agree the minimum overs for a result before the match: 5 overs of the chase is the usual T20 figure.
- When you score in the Manage Cricket scoring app, record the stoppage and the app works out the revised target with the same table.
- A rain-shortened match still counts in the points table, with adjusted figures: the net run rate guide explains how.