Guyana is slowly becoming the home of the Duckworth-Lewis Method.  While Zimbabwe imploded making the rain-caused abandonment a welcome cover for their embarrassing performance. England were definitely lucky. 120/8 against Ireland, under the D-L method, Ireland needed about 27 in 5 overs and they were already 14 in 3.3. overs.

So more than Mahela’s batting and Darren Sammy’s virtuoso performances, it is the maths pair about whom there is much discussion. So let’s spend a few words about the method.

There are a number of fundamental axioms when adjusting a score for a match interrupted by rain

  • It has to be fair to both teams i.e. the team chasing the score must feel it is within their reach while the team bowling should feel it is defendable
  • There should be change in the balance of the game – i.e. if one team has complete dominance of the game, then that state of the match should continue.

The D-L method was adopted in 1999. Until then there was no standard rule. Every tournament or series had its own version of the rules. There were some which were highly bizarre (what was even more bizarre was that captains actually agreed to play under the rules). Like the 1992 World Cup semi-final between England and South Africa. Incidentally, the target of 22 in 1 ball under the D-L method would have been 5 runs in 1 ball (4 runs to tie).

The basic logic of the D-L method is summarised below

  • Based on a set of historical with appropriate weightages on recency, status of teams (e.g. test playing nations, associate nations, etc) and other factors, a table of par scores for 50 over games and 20 over games is created. This table is regularly updated as scoresheets of new matches come in.
  • A multiplication table comprising of the D-L formula – % combined resources and the likely score they can make is prepared. Combined resources include wickets and overs with some weightages.

Here are the ICC rules on application of the D-L Method.

The D-L method sets revised targets in rain-interrupted limited-overs matches in accordance with the relative run scoring resources which are at the disposal of the two sides.

These are not in direct proportion to the number of overs available to be faced, as with the average run rate method of correction. Instead they depend on how many overs are to go and how many wickets are down when the interruptions occur.

To calculate the revised targets, you need to know the resources available at the stage of the match when suspensions and resumption of play occur. All possible values of resources have been pre-calculated and these are listed in the accompanying table.

Actually, the demand for simplicity is basically about application. With the appropriate formulas and calculators given to the umpires, I guess there is no problem whatsoever. Commentators may say many things out of ignorance but a little digging and studying the method helps.

Having said that, looking at all the matches where D-L has been applied, I would say there has not been any loss of fairness or balance. One has to also note that it is the umpires who decide on the number of overs.

I will close this post here. I will spend some more time reading up on D-L and write about it in a subsequent post.


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