Rain formula came after 1992 World Cup semi-final fiasco January 1, 2007

A decade of Duckworth-Lewis

Cricinfo staff

Duckworth-Lewis has been deciding rain-hit matches for 10 years © Getty Images
It still often has players and commentators unfolding sheets of paper, and leaves supporters scratching their heads to work out the sums, but the Duckworth-Lewis method of reaching targets in interrupted one-day internationals has now been the official decider for 10 years.

On January 1, 1997, Zimbabwe beat England by seven runs at Harare after the target had been adjusted with the D-L method, the first match to be effected after the method was sanctioned by the ICC. The third ODI between New Zealand and Sri Lanka at Christchurch on Tuesday will mark 10 years at the top.

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

However, it had been used for a lengthy period of time before then. 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 World Cup in 1999 in England, although remarkably it was not necessary to implement it throughout the entire tournament.

The main impetus for the development of what became known as the Duckworth-Lewis method was the 1992 World Cup semi-final fiasco when, after a short rain delay at the SCG, 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 realised that it was a mathematical problem that required a mathematical solution," recalls Duckworth.

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, the former ICC High Performance Manager and now Pakistan coach, the D-L method is the best that anyone has managed to come up with.

"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."

Although the majority of use for the D-L method have been because of rain or bad light, it 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).