DUCKWORTH-LEWIS-STERN SYSTEM

About: 

• The Duckworth–Lewis (D/L) method is a mathematical formula used to calculate the target score for the team batting second in a limited overs cricket match interrupted by weather (e.g. Rain) or other circumstances. 
  
  
• Nomenclature: The D/L method was devised by two English statisticians, Frank Duckworth and Tony Lewis. After their retirements, Professor Steven Stern became the custodian of the method. In 2014, it was renamed the Duckworth–Lewis–Stern method (or DLS method). 
  
  
• History: It was first used in international cricket in 1997 and was formally adopted by the ICC in 1999. 
  
  

Working: 

• Each team in a limited-overs match has two resources available with which to score runs (overs to play and wickets remaining). 
  
  
• The target is revised proportionally in the combination of these two resources to set a statistically fair target for the second team's innings, which is the same difficulty as the original target. 
  
  

Recent update: 

• The International Cricket Council (ICC) announced the new version of the Duckworth-Lewis-Stern (DLS) System that comes into effect from September 30, 2018.
  
  
• This is the third version but second update of the DLS System since its introduction into international cricket in 2014
  
  
• It is based on information from 700 ODIs and 428 T20 Internationals, which comprise over 240,000 outcomes of individual deliveries.
  
  
• This has been carried out following a detailed ball-by-ball analysis of scoring patterns, including in the Powerplays, in all limited overs internationals played during the previous four years.