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Understanding the Duckworth-Lewis-Stern Method in Cricket: Can it be made fairer?

*Tushar Kumar




Introduction


A staunch follower of a sport will usually have a thorough knowledge of that sport, whether it is the history associated with it, how it is played, or the rules governing the sport. However, as far as cricket is concerned, being the national sport of Australia and England and one of the most decorated sports in South Asia,[1] the unfamiliarity of cricket enthusiasts with the application of the Duckworth Lewis Stern Method (DLS Method) is quite surprising. This obliviousness about DLS Method is restricted to its followers and cricketers, who usually face the implications of its application in the game.[2]


DLS Method is a formula devised to moderate the batting side scores in cricket once a limited over match is interrupted due to rain, bad light, or any other disturbance.[3] However, its usage on interruptions in the game has not been devoid of controversies[4] as the outcome of those matches has invariably changed, much to the dismay of the losing team. To this extent, this article is an attempt by the author to unravel the DLS Method’s mechanism, evaluate its effectiveness and provide suggestions to optimise its functioning. The aim of this article does not extend to analysing the mathematical equations and/or such relationships involved in it.


Evolution of the DLS Method and its Essence


The original Duckworth Lewis Method (Standard Edition) or the D/L Method was invented by FJ Duckworth and AJ Lewis in 1998. The D/L Method works on the premise that, once the match is interrupted, the batting side has two resources available for scoring runs - wickets and overs left to play. A mathematical relationship has been defined, which functions based on these two resources.



An extract of the standard edition table comprising of the calculated values after the data is put in the desired equation [5]


However, in 2003, it was observed that the Standard Edition was not suited for runs scored above the moderate/average scores as, in such matches, more runs were scored at a quicker rate towards the latter part of the innings.[6] For instance, the target of 360 runs in 50 overs, set up by Australia against India in the 2003 World Cup final,[7] was an above par score [8], and D/L Method would have set India a comparatively low target had there been a significant interruption. To account for such situations, a computerised Professional Edition of D/L Method was introduced in 2003, which introduced a match factor into the Standard Edition and thereby incorporated fairness for high scoring matches. Later on, to ensure that the method is commensurate with the ever-increasing high scoring matches, the Professional Method was further redefined by Steven Stern to make it the present DLS Method. The original Standard Edition still continues to be in existence and according to the International Cricket Council (ICC), the DLS Method has to be used in all matches, subject to the condition where there is non-availability of computer or any malfunction, in which case the Standard Edition would be used. Some lower-level competitions or club matches still continue to use the Standard Edition when they are unable to procure the DLS software from the administration.[9] Furthermore, ICC's DLS Method is updated periodically to make it suitable for the rapidly changing cricketing conditions. For instance, recently, the software had been transformed to consider the significance of lower-order partnerships.[10]


Conclusion & Suggestions


Every sport is an unpredictable spectacle, and cricket is no exception. Interruptions, howsoever disheartening for religious followers, are bound to happen, and there has to be an optimum or a near to optimum system for accounting for those interruptions. This system would inevitably turn out to be unsatisfactory for a specific section of followers or players, or teams. The notion of fairness is an abstract one as a method, as subjective as this, can never be devoid of limitations. However, as an alternative, it is high time that the ICC introduces the mandatory practice of keeping one reserve day for crucial ICC tournaments so that matches could be conveniently shifted to the reserve day eliminating the subjectivity resulting from usage of the DLS Method.


Furthermore, the author believes that certain additional parameters would optimise the operation of the DLS Method if incorporated. Firstly, the Standard Edition, which is still being used in some club competitions, relies on the concept of G50 or an average score total score in a 50-over match, which is presently fixed at 245. The author believes that the idea of G50 is obsolete and does not fit in with the norms of contemporary cricket. Its usage in the past could have been considered legitimate because, during those times, average runs hovered around a certain threshold, with a minuscule of matches turning out to be high scoring. Instead of G50 being pre-determined, it must be made match specific by taking into account the actual run rate of the team whose target is being revised. For example, if the match is interrupted due to rain and the batting team’s score is 180 after 30 overs, then the average total score or G50 would be equal to Net run rate (6 runs per over, in this case) * 50 overs, which will be 300 runs. Some teams may also unduly benefit from the pre-determined value of G50 as the average total score of 245 runs in 50 overs presumes the net run rate of the team during the entire innings to be 4.9, which does not represent the innings of a team scoring at 3.5 - 4.5 runs per over. Hence, determining G50 based on net run rate makes it more representative of the batting side’s innings.


Secondly, the DLS Method algorithm needs to distinguish between batsman, bowlers, and all-rounders. When it comes to moderating the team’s scores, not distinguishing the all-rounders from bowlers would be unfair. For example, the team batting first, i.e. Team A, has a score of 180/4 after 30 overs when rain interrupted the match. Suppose Team A is playing with 6 batsmen, 3 all-rounders, and 2 bowlers instead of Team B, which is playing with 7 batsmen and 4 bowlers, then according to the present algorithm. In that case, Team A’s remaining resources will be determined without recognising that they still have 4-5 batsmen (including all-rounders who can bat), making their remaining 6 wickets on an equal footing with Team B’s remaining 6 wickets. The author suggests that due weights/proportionate credits should be given to batsmen, bowlers and all-rounders separately. However, equal weights must be given to every batsman, every bowler and every all-rounder on the basis of the list released by ICC annually for the three categories separately, and not on the basis of the ranking of a player, as proposed recently by two authors from Pakistan,[11] as then the programming of the algorithm would become highly uncertain.


Thirdly, for the DLS Method to be applicable in T20 International matches, both the playing sides must play a minimum of 5 overs.[12] Notwithstanding the constant criticism of the DLS Method in T20 International matches, this basic condition of playing a minimum of 5 overs clearly has unfair consequences for the side batting first, as evidenced in the past. If the team batting first has played 20 overs and later on, due to interruption, the match is reduced to 5 overs per side, then the team chasing the revised target will inevitably be at an advantageous position and can take more risks as it has 10 wickets in hand. For instance, the IPL Match of 2017, where, after the DLS Method’s application, the team batting second was given a target of 48 runs in 6 overs,[13] which is undoubtedly a low time frame for the bowling team to bowl them out. Reducing the number of wickets available to the chasing team is something that has been constantly propounded by many critics of the DLS method,[14] however, the author believes that reducing wickets would not only prove to be unsatisfactory but also arbitrary as the chasing team might play with all the batsmen, or the team composition would have to be re-determined proportionately. The author proposes that both sides must play a minimum of 10 overs for the DLS Method to be applied so that the defending team has some leeway in bowling out the chasing team.


The author believes that the suggestions mentioned above will not completely end the controversies surrounding the DLS Method but will optimise the fairness attached to its applicability.


*The author is a law scholar from Dr Ram Manohar Lohiya National Law University, Lucknow.


(The image used here is for representational purposes only)




References


1. Majumdar, Boria. “South Asia’s Cricket Obsession.” BBC News, 21st December, 2006, http://news.bbc.co.uk/2/hi/south_asia/6171549.stm.

2. “Don’t Really Understand the Duckworth Lewis Method.” The Quint, 8th October, 2017, https://www.thequint.com/sports/cricket/virat-kohli-duckworth-lewis-method-india-vs-australia; “SA didn’t blunder over target: Coach.” Rediff.com, 4th March, 2003, https://www.rediff.com/wc2003/2003/mar/04run.htm.

3. Stern, E. Steven, “The Duckworth-Lewis-Stern method: extending the Duckworth-Lewis methodology to deal with modern scoring rates.” Journal of Operational Research Society, 2016, 1-12, doi:10.1057/jors.2016.30.

4. “Here are controversial cricket matches that were affected by D/L method.” Business Standard, 3rd April, 2020, https://www.business-standard.com/article/sports/here-are-controversial-cricket-matches-that-were-affected-by-d-l-method-120040300317_1.html; Lancaster, Rob. “Why Cricket's Duckworth-Lewis Method Is Outdated and Needs a Complete Overhaul.” Bleacher Report, 25th June, 2015, https://bleacherreport.com/articles/2505332-why-crickets-duckworth-lewis-method-is-outdated-and-needs-a-complete-overhaul; Gardner, Ben. “Forget the interval, the ICC’s rain rule cost Australia the first T20I.” Wisden, 4th November, 2019, https://wisden.com/stories/international-cricket/forget-the-interval-the-iccs-rain-rule-cost-australia-the-first-t20i.

5. Duckworth-lewis methodology for re-calculating the target score in an interrupted match, available at https://www.icc-cricket.com/about/cricket/rules-and-regulations/duckworth-lewis-stern

6. Duckworth, Frank, et. al. “Cricket's raining champion: Two decades of Duckworth–Lewis (and Stern).” Significance Magazine, June, 2019, pages 30-35, https://doi.org/10.1111/j.1740-9713.2019.01278.x

7. http://www.espncricinfo.com/series/8039/scorecard/65286/australia-vs-india-final-icc-world-cup-2002-03

8. Venkat, Ravi. “300 plus totals in ODI cricket.” Holding Willey, 24th July, 2018, http://www.holdingwilley.com/article/stories-from-numbers/300-plus-totals-in-ODI-cricket.

9. “Duckworth-Lewis Methodology For Re-Calculating the Target Score In An Interrupted Match.” International Cricket Council, https://icc-static-files.s3.amazonaws.com/ICC/document/2017/01/09/ca50a5e9-0241-494a-8773-d0cec059b31f/DuckworthLewis-Methodology.pdf.

10. Supra note 6.

11. Ali, Fayyaz and Khusro, Shah. “Player Ranking: A Solution to the Duckworth/ Lewis Method Problems.” Research Gate, November, 2018, DOI: 10.1109/ICET.2018.8603602.

12. https://www.icc-cricket.com/about/cricket/rules-and-regulations/duckworth-lewis-stern (Video about the explanation of DLS).

13. “Kolkata Knight Riders won by 7 wickets (DLS Method).” Indian Premier League, 16th May, 2017, https://www.iplt20.com/match/2017/58

14. “The DLS methodology: answers to frequently asked questions.” International Cricket Council, Question No. 14.