Tuesday, March 11, 2008

All about Duckworth-Lewis method

A number of one-day international matches played in the ongoing Commonwealth Bank series suffered the wrath of bad weather. While the first two ties ended up being completely washed out by incessant rain, a few of the other rain shortened games had to be decided by the Duckworth-Lewis method.

While most of the cricket lovers may have heard the term (Duckworth-Lewis), not many might be thoroughly acquaint with the working of this rather complex system. If you too have ever been perplexed by something called the Duckworth-Lewis method (D/L method), then this piece of article may just be the thing that will answer all your queries.




The basics first

Duckworth-Lewis method is a mathematical way of calculating the winning target for the team batting second in a rain affected one-day or Twenty20 international cricket match. Considered to be one of the most accurate ways of calculating the target score, the Duckworth-Lewis method attempts to predict what would have actually happened in a game had it gone through its full course without any interruption.

The method was designed taking into account the number of overs a team has as well as the wickets in hand. Both these resources have been known to have a close relation with the number of runs a team scores from any point in the innings. D/L makes use of a table to predict the result of a rain shortened game.

Ex – In the CB series one day international match played between Sri Lanka and India at Canberra, India batted first and posted a total of 195 runs off 29 overs (the match started late because of heavy rain, reducing the game to 29 overs a side). With another 9 overs lost due to rain, Sri Lanka came in to bat with the target reduced to 154 runs off 21 overs. The target, in this case was calculated considering a possible situation where India only had 21 overs to bat.

Besides being a relatively simple method to apply, Duckworth-Lewis is also known to provoke a good deal of discussion and debate on the cricket ground, which often adds a bit of spark to a dragging, rain affected game. When applied in a 50 over match, each team is required to face at least 20 overs for a match to be considered complete while the number of overs needed to complete a Twenty20 match is 5 per innings.

From the pages of history

Named after English statisticians, Frank Duckworth and Tony Lewis, the method was first used in international cricket during the 1996/7 season in a one day match played between England and Zimbabwe. Subsequently, in 2001, it was adopted by the ICC as the standard method for deciding the result of a rain shortened match. Having undergone several modifications since then, D/L has been used as a successful method to decide the result of rain shortened games.