The Duckwoth Lewis Method

This article is specially meant for the cricket crazy junta in our country and in our college. The Duckworth Lewis method has been in use for quite sometime now for resetting targets in rain shortened one dayers and T-20s.For many of us its very goofy and complicated and we wonder whether its fair, but I would like to tell you people out there its fair, at least much fairer than most of the other “rain rules” as they call it. 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 Quantitative Methods in Management in the Business School at Oxford Brookes University.
Had this method been there at the 1992 world cup, South Africa would not have had to score 22 runs off one ball.
I hope u have as much fun reading the article as I had writing it.

Basic Idea of the Method:

The basic concept is that the batting team has two types of resources with which they can make as many runs as possible, wickets and overs left.The percentage of resources lost is determined by a table and a revised score is determined by scaling down the first innings target if the team batting first had the same amount of resources available.An extract of the table has been given to let you understand(those who want the full table can leave their email ids in the comment, I’ll mail them).

Table : Extract from the table of resource percentages remaining

Reading the table:

Reading the table is very easy, suppose rain stops play in the second innings and the 2nd team has played 30 overs and has lost 5 wickets.
Then the percentage of resources remaining from the table is 40%.

Applying the D/L Method:

1. For each team’s innings
(a) from the table note the resource percentage the team had available at the start of their innings;
(b) using the table, calculate the resource percentage lost by each interruption;
(c) hence calculate the resource percentage available.
2. If Team 2 have less resources available than Team 1, then calculate the ratio of the resources available to the two teams. Team 2’s revised target is obtained by scaling down Team 1’s score by this ratio. The figure so obtained is rounded down to the next whole number to give the score needed for a tie. The target is one more run than this. The procedure by which a tie is always possible is a consequence of a change in playing conditions introduced internationally from April 1999.
3. If Team 2 have more resources available than Team 1, then calculate the amount by which Team 2’s resource percentage exceeds Team 1’s. Work out this excess as a percentage of 225 [the average 50-over score in ‘first class’ matches and one-day internationals (ODIs)]. Rounding this down to the next whole number gives the extra runs to add on to Team 1’s score to give the score to tie. Adding one run gives Team 2’s target.

I know this would have gone like a bouncer over your head(at least it went over mine).It would be better if we had an example.

In a practical scenario 3 types of interruptions r possible:

1.The second team is chasing a target and rain interrupts and no further match can take place and a par score has to be determined.
2.The 2nd team is chasing and rain interruption leads to a loss of a few overs and a revised target has to be determined.
3.1st innings and the innings ends at thar interruption and the 2nd team has to be set a target because the 1st team was playing thinking the game to be 50 overs and they were pacing their innings at the point where rain interrupted so 2nd team has to set a target greater than what 1st team had scored.

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