1. Duckworth/Lewis is the method of resetting targets in interrupted one-day cricket matches by Frank Duckworth & Tony Lewis.
2. The D/L method of resetting targets in rain-affected one-day cricket matches was trialled successfully during 1997 by the International Cricket Council (ICC), the ECB (England & Wales Cricket Board) and the Zimbabwe Cricket Union (ZCU).
3. The method is the invention of Frank Duckworth and Tony Lewis. Frank is a consultant statistician and editor of the Royal Statistical Society's monthly news magazine, RSS NEWS. Tony is a lecturer in mathematical subjects in the Faculty of Computer Studies and Mathematics at the University of the West of England,
4. The D/L method works using the notion that teams have two resources with which to make as many runs as they can, these are the number of overs they have still to receive and the number of wickets they have in hand. From any stage in their innings, their further run-scoring capability depends on both these two resources in combination.
5. When a match is shortened after it has begun, the resources of one or both teams are depleted and the two teams usually have different amounts of resource for their innings. In this case a revised target must be set.
6. In the version of D/L most commonly in use in international and first class matches (the 'Professional Edition'), the target for the team batting second ('Team 2') is adjusted up or down from the total the team batting first ('Team 1') scored, in proportion to the two teams' resources (combination of overs and wickets available).
7. If it's a 50-over match and Team 1 completed its innings uninterrupted, then they had 100% resource available to them, so the formula simplifies to.