Editing Duckworth–Lewis–Stern method (section)

==Use and updates==
The published table that underpins the D/L method is regularly updated, using source data from more recent matches; this is done on 1 July annually.<ref>{{cite news |url=https://www.theregister.co.uk/2016/09/12/just_not_cricket_microsofts_big_data_googly_declared_no_ball_bowled_by_rain_man/  |title=Simon Sharwood |first=Simon |last=Sharwood |date=12 Sep 2016 |work=[[The Register]]}} (Professor Steven Sern interview)</ref>

For 50-over matches decided by D/L, each team must face at least 20 overs for the result to be valid, and for [[Twenty20]] games decided by D/L, each side must face at least five overs, unless one or both teams are bowled out and/or the second team reaches its target in fewer overs. 

If the conditions prevent a match from reaching this minimum length, it is declared a [[no result]].

===1996–2003 – Single version===
Until 2003, a single version of D/L was in use. This used a single published reference table of total resource percentages remaining for all possible combinations of overs and wickets,<ref name="DLMethod">[http://static.ecb.co.uk/files/3140-fc-domestic-duckworthlewis-2013-p127-140-lr-12376.pdf Duckworth/Lewis Method of Re-calculating the Target Score in an Interrupted Match] ECB, 2013 {{webarchive|url=https://web.archive.org/web/20140222211845/http://static.ecb.co.uk/files/3140-fc-domestic-duckworthlewis-2013-p127-140-lr-12376.pdf |date=22 February 2014 }}</ref> and some simple [[mathematical]] calculations, and was relatively transparent and straightforward to implement.

However, a flaw in how it handled very high first innings scores (350+) became apparent from the 1999 Cricket World Cup match in Bristol between India and Kenya. Tony Lewis noticed that there was an inherent weakness in the formula that would give a noticeable advantage to the side chasing a total in excess of 350. A correction was built into the formula and the software, but was not fully adopted until 2004. One-day matches were achieving significantly higher scores than in previous decades, affecting the historical relationship between resources and runs. The second version uses more sophisticated statistical modelling, but does not use a single table of resource percentages. Instead, the percentages also vary with score, so a computer is required.<ref name=FAQ/> Therefore, it loses some of the previous advantages of transparency and simplicity.

In 2002 the resource percentages were revised, following an extensive analysis of limited overs matches, and there was a change to the [[Duckworth–Lewis method#Step 2. Convert the two teams' batting resources into Team 2's target score|G50]] for ODIs. (G50 is the average score expected from the team batting first in an uninterrupted 50 overs-per-innings match.) G50 was changed to 235 for ODIs. These changes came into effect on 1 September 2002.<ref name="DLM2002"/> As of 2014, these resource percentages are the ones still in use in the Standard Edition, though G50 has subsequently changed.

The tables show how the percentages were in 1999 and 2001, and what they were changed to in 2002. Mostly they were reduced.

{|
|
{| class="wikitable" style=" margin: 1em 1em 1em 1em; text-align:center; width:25%;"
|+ Percentage total resources remaining: 1999<ref>{{cite web|url=http://static.espncricinfo.com/db/ABOUT_CRICKET/RAIN_RULES/DUCKWORTH_LEWIS_1999.html|title= The Duckworth-Lewis Method (1999)|work=Cricinfo|publisher=ESPN Sports Media|date=1999|author1=Frank Duckworth |author2=Tony Lewis}}</ref> and 2001<ref>{{cite web|url=http://static.espncricinfo.com/db/ABOUT_CRICKET/RAIN_RULES/DUCKWORTH_LEWIS_2001.html|title=The Duckworth-Lewis Method (2001)|date=2001|author1=Frank Duckworth |author2=Tony Lewis |work=Cricinfo|publisher=ESPN Sports Media}}</ref>
|-
! rowspan="2" style="background: #ffdead;" | Overs remaining
! colspan="5" style="background: #ffdead;" | Wickets in hand
|-
| '''10''' || '''8''' || '''5''' || '''3''' || '''1''' 
|-
| '''50''' || 100.0 || 83.8 || 49.5 || 26.5 || 7.6 
|-
| '''40''' || 90.3 || 77.6 || 48.3 || 26.4 || 7.6 
|-
| '''30''' || 77.1 || 68.2 || 45.7 || 26.2 || 7.6 
|-
| '''20''' || 58.9 || 54.0 || 40.0 || 25.2 || 7.6 
|-
| '''10''' || 34.1 || 32.5 || 27.5 || 20.6 || 7.5 
|-
| '''5''' || 18.4 || 17.9 || 16.4 || 14.0 || 7.0 
|}
|
{| class="wikitable" style=" margin: 1em 1em 1em 1em; text-align:center; width:25%;"
|+ Percentage total resources remaining: 2002<ref name="DLM2002"/>
|-
! rowspan="2" style="background: #ffdead;" | Overs remaining
! colspan="5" style="background: #ffdead;" | Wickets in hand
|-
| '''10''' || '''8''' || '''5''' || '''3''' || '''1''' 
|-
| '''50''' || 100.0 || 85.1 || 49.0 || 22.0 || 4.7
|-
| '''40''' || 89.3 || 77.8 || 47.6 || 22.0 || 4.7
|-
| '''30''' || 75.1 || 67.3 || 44.7 || 21.8 || 4.7
|-
| '''20''' || 56.6 || 52.4 || 38.6 || 21.2 || 4.7
|-
| '''10''' || 32.1 || 30.8 || 26.1 || 17.9 || 4.7
|-
| '''5''' || 17.2 || 16.8 || 15.4 || 12.5 || 4.6 
|}
|}

===2004 – Adoption of second version===
The original version was named the Standard Edition, and the new version was named the Professional Edition. Tony Lewis said, "We were then [at the time of the [[2003 Cricket World Cup Final|2003 World Cup Final]]] using what is now known as the Standard Edition. ... Australia got 359 and that showed up the flaws and straight away the next edition was introduced which handled high scores much better. The par score for India is likely to be much higher now."<ref>{{cite web|url=http://www.dnaindia.com/sport/report-tony-lewis-of-duckworth-lewis-interview-journalists-denigrate-system-by-publishing-rubbish-without-understanding-1880623|title= Tony Lewis, of Duckworth-Lewis, Interview: Journalists denigrate system by publishing 'rubbish' without understanding|date= 27 August 2013|work=DNA|publisher=Diligent Media}}</ref>

Duckworth and Lewis wrote, "When the side batting first score at or below the average for top level cricket&nbsp;..., the results of applying the Professional Edition are generally similar to those from the Standard Edition. For higher scoring matches, the results start to diverge and the difference increases the higher the first innings total. In effect there is now a different table of resource percentages for every total score in the Team 1 innings."<ref name=FAQ/> The Professional Edition has been in use in all international one-day cricket matches since early 2004. This edition also removed the use of the G50 constant when dealing with interruptions in the first innings.<ref name=FAQ/>

The decision on which edition should be used is for the cricket authority which runs the particular competition.<ref name=FAQ/> The ICC Playing Handbook requires the use of the Professional Edition for internationals.<ref name="ICCPH1314">{{cite web|url=http://icc-live.s3.amazonaws.com/cms/media/about_docs/526958a73c839-Playing%20Handbook.pdf|title=ICC Playing Handbook 2013/14|page=Section 6|publisher=International Cricket Council|via=Amazon Web Server|date=2013}}</ref><ref name="ICCPH">{{Cite web |url=http://www.icc-cricket.com/about/113/publications/playing-handbook |title=ICC Playing Handbook |access-date=18 April 2014 |archive-url=https://web.archive.org/web/20140419012918/http://www.icc-cricket.com/about/113/publications/playing-handbook |archive-date=19 April 2014 |url-status=dead |df=dmy-all }}</ref> This also applies to most countries' national competitions.<ref name=FAQ/> At lower levels of the game, where use of a computer cannot always be guaranteed, the Standard Edition is used.<ref name=FAQ/>

===2009 - Twenty20 updates===
In June 2009, it was reported that the D/L method would be reviewed for the Twenty20 format after its appropriateness was questioned in the quickest version of the game. Lewis was quoted admitting that "Certainly, people have suggested that we need to look very carefully and see whether in fact the numbers in our formula are totally appropriate for the Twenty20 game."<ref>[http://www.expressindia.com/latest-news/DuckworthLewis-to-review-their-formula-for-T20-matches/477860/ Duckworth–Lewis to review their formula for T20 matches] Indian Express, 17 June 2009 {{webarchive |url=https://web.archive.org/web/20121010101509/http://www.expressindia.com/latest-news/DuckworthLewis-to-review-their-formula-for-T20-matches/477860/ |date=10 October 2012 }}</ref>

===2015 – Becomes DLS===
For the [[2015 Cricket World Cup|2015 World Cup]], the ICC implemented the Duckworth–Lewis–Stern formula, which included work by the new custodian of the method, Professor [[Steven Stern]], from the Department of Statistics at [[Queensland University of Technology]]. These changes recognised that teams need to start out with a higher scoring rate when chasing high targets rather than keep wickets in hand.<ref>{{cite web|title=Duckworth-Lewis method in new avatar for World Cup|url=http://www.espncricinfo.com/icc-cricket-world-cup-2015/content/story/841481.html|work=Cricinfo|publisher=ESPN Sports Media|access-date=7 July 2016|date=1 March 2015|author=Daniel Brettig}}</ref>