Ten years at the top for Duckworth-Lewis

While we all might not understand the intricacies of the Duckworth-Lewis method of scoring in the one-day form of the game, its presence is now as familiar to us as the white ball and coloured clothing.

And after ten years, the system is working better than ever.

On 1 January 1997, Zimbabwe beat England by six runs, after the target had been revised, in an ODI at Harare in what was the very first ICC-sanctioned match to operate the Duckworth-Lewis method.

When New Zealand plays Sri Lanka in the 3rd ODI of their current series in Christchurch tomorrow (Tuesday) the method will have entered its second decade in the top flight.

The revolutionary and ingenious system was devised by UK-based statisticians Frank Duckworth and Tony Lewis and was formally adopted by the ICC in 2001, firstly on a trial basis, and from 2004 on a more permanent basis, being subject to three-yearly review.

But that was not the start. Prior to this, the D-L method was applied in the ICC Trophy in Malaysia in 1997 and in New Zealand, South Africa, Pakistan, India and West Indies in 1998. The ICC adopted this system for the ICC Cricket World Cup in 1999 in England, although remarkably it was not necessary to implement it throughout the entire tournament.

Since then, whenever there is an unscheduled interruption in play, Messrs Duckworth and Lewis - or at least the results of their calculations - take centre stage.

The main impetus for the development of what became known as the Duckworth-Lewis method was the 1992 ICC Cricket World Cup semi-final fiasco when, after a short rain delay at the Sydney Cricket Ground, South Africa went from needing 22 runs to beat England from 13 balls to needing the same 22 runs, but from just one ball.

"I recall hearing Christopher Martin-Jenkins on radio saying 'surely someone, somewhere could come up with something better' and I soon realized that it was a mathematical problem that required a mathematical solution," recalls Duckworth.

A good measure of its fairness is the fact that the proportion of matches won by the team batting first is virtually the same (at 52 per cent) for uninterrupted and interrupted matches using the D-L method.

Lewis adds: "It is very satisfying when watching matches that players generally accept revised targets now as fair, in contrast with the previous systems, and that we have made a significant contribution to the history and development of the game."

According to Bob Woolmer, former ICC High Performance Manager and now Pakistan national coach, the Duckworth-Lewis method is the best that anyone has managed to come up with.

"Ever since the ICC Cricket World Cup 1992 in Australia when South Africa were set 22 runs to win off 1 ball, I believe that the revised version of the Duckworth-Lewis method has been the fairest system yet for interrupted cricket matches.

"I believe there will be moments in one-day cricket which will test any system and as long as the D-L method is monitored, it will remain the fairest system. The inventors should be congratulated for arriving at this formula," Woolmer said.

David Richardson, ICC's General Manager - Cricket, said: "The D-L method has been adjusted and amended over time taking account of the changing scoring trends in ODI cricket. The lack of a serious controversy surrounding the result of a rain-curtailed match is indicative of the method's proficiency.

"No one likes it when the result of a game has to be settled by the mathematicians. Cricket, by its nature, is unpredictable and fortunes can fluctuate extravagantly during the course of a match.

"However, if one is forced to find an answer to the question 'who is winning' at a particular time during a match, the D-L method gives you as fair a method of doing so as you are likely to get."

Although the great majority of these have been because of rain or bad light, D-L has also been used for stoppages due to 14 cases of floodlight failure, three of crowd disturbances, and one each for sandstorm (Rawalpindi), snow (Durham) and the sun (Derby).

For more information about the Duckworth-Lewis method including all the mathematics behind it, go to