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ShareIn a one-on-one with DNA, Tony Lewis of the famed Duckworth-Lewis pair says the D/L method is logical and simple but one must be willing enough to understand it.
What inspired you to come up with the mathematical solution called Duckworth-Lewis?
The 1992 World Cup semifinal was the catalyst for many people to try to find a fair rain-rule. We realised that it was not a simple problem; it was a mathematical problem that required a mathematical solution. The one we came up with has since been acclaimed by the academic community.
Is it necessary to know the intricacies of the game? Do you have a cricketing background?
I played for my grammar school and village teams mainly as a stubborn opening bat. Nowadays it is only armchair cricket but all these give the necessary understanding of the way the game is played and of its intricacies.
The method has never been fully understood by a layman or a cricket fan...
We dispute "never". If you trawl the Internet cricket chat sites you will see there are many correspondents who can provide succinct and sensible answers to bloggers' questions on how the D-L method works. The method can be easily understood if one is prepared to spend a few minutes studying the D-L pages of sites such as Cricinfo (www.cricinfo.com).
Many teams have lost games by miscalculation. For example, South Africa in 2003 World Cup or West Indies coach John Dyson recently against England. How can this be rectified?
Again, we don't agree with "many". There have been a few high-profile errors such as the two you mention. But they have nearly always been misreading of the information supplied. In the 2003 World Cup, the opposing Sri Lankan skipper (versus South Africa), Jayasuriya, knew the state of the game. So did Andrew Strauss for England (versus West Indies) in the recent case in Guyana. Nevertheless, we are always receptive to the need to make reviews in the way the D-L information is conveyed in order to minimise the chances of such errors.
It has been over 10 years since its inception and you have since updated the system. Don't you think players, support staff and administrators should be trained to work better with it?
Apart from the well-publicised errors, there are very few errors made by the administrators of the D-L method at the higher levels of the game. Detailed instructions are provided and frequent seminars are held to ensure that it runs smoothly. Nevertheless, when there is a problem we always review instructions to try to eliminate them.
Has any player or team management ever come up to you to clear doubts?
In the early years of the method's use the rational of some of the revised targets was not fully understood, especially when the team batting second have to score more runs to win than the team batting first. Generally, now, however, the targets are accepted as logical, although we still get the occasional query from management but only when their team has lost through D-L!
Is there a way to make your table of resource percentages easy to understand?
Many websites contain several pages of explanation on how the tables are used. In addition, our booklet, Your Comprehensive Guide to the Duckworth-Lewis Method, published by Marine Sports in India, contains a comprehensive explanation.
In the infamous South Africa vs England 1992 World Cup match, the target was revised from 22 in seven balls to an impossible 22 in one ball. What would it have been according to Duckworth-Lewis?
Using the current D-L resource tables, which can be seen on the ICC website, the revised target would have been 235, requiring SA to score four runs from one ball; they would have still had a fighting chance of winning the game.
There is also a VJD system developed by V Jayadevan from India. Where does D-L score above it?
We hear of about three or four suggested alternative systems every year, but we don't regard it as our duty to comment on these. It is up to the cricket authorities to decide, and ICC recently reviewed all alternatives and concluded that D-L was the best.
For cricket followers, D-L is almost incomprehensible. Can you do something about this?
Again we disagree with your generalisation and point to the many lucid explanations of the D-L method by cricket followers on websites. Education is important on this, as well as the willingness to be educated! Studying the web pages will assist that understanding. However, we sometimes feel, particularly with some journalists, that they regard the state of ignorance as preferable to the spending of effort to learn about the method. We have frequently offered to give seminars to journalists on the method, but there have been no takers. We seriously wonder why not!
Are you developing any other systems?
Based on the D/L method, I have created performance measures in ODIs that better assess and compare the contribution of players. In contrast to the standard batting and bowling averages and strike rates, these measures take better account of the stage of the innings that runs are made or conceded, and wickets taken or lost.
