Duckworth-Lewis method

Duckwoth-Lewis method is generally accepted a fair method of deciding the revised targets in rain interrupted matches, but at times does gets into controversies. This post covers in layman terms what Duckworth-Lewis(D/L) method is about and also gives you some facts regarding the origin of the method.
I came to know from wikipedia that 'The D/L method was devised by two English statisticians, Frank Duckworth and Tony Lewis, originating from an undergraduate final-year project at the University of the West of England.' Even I'm bound to do my final year project, which would start in a months time, so D/L method originating from a UG student is what fails to impress me, I get the feeling that ICC deserves a higher qualified statisticians to design a method for them. There are certainly some draw backs in the D/L method which would be discussed appropriately later in the post as they would mean more if the method of calculation is understood.
D/L method uses the principle of resources and would calculate the targets. Resources available are determined from the following factors:
* Number of over left.
* Number of wickets in hand.

The principle followed by D/L is simple , more resources you have more is the number of runs you make. for example a team having 25 overs left still has more resources than when it has 20 overs left at the same number of wickets down. A team having 7 wickets in hand has more resources than a team having 5 wickets in hand with the same number of overs left.
D/L method uses the scoring rates and statistics from previous matches and had concluded with a weight of resource to be given for the number of wickets left.

The simple formula for the revised target in a rain interrupted match is:
'T = (S x R2/R1) + 1 (rounded down to a whole number, if necessary)'

Here T is the target, S is the score made by team batted first in the resources R1 and R2 are the resources with team batting second after the interruption by rain.
The method goes on and on and is not easy to be listed on this blog, so the technical details of the method will be stopped here.

Every one remembers the 1992 worldcup semifinal where South Africa needed 22 runs from 13 balls to spare before the rain came down. The tournament used a method called "best-scoring overs" which recalculated the total and made it to 21 runs from 1 ball remaining. Clearly the method was a flaw. D/L method scores in this case it would reduce the total to 5 runs from the last ball for a win and 4 runs for a draw, which is considerably fair. D/L method anyway was born in 1996 only and was used first between Zimbabwe & England in 1996/7 which Zimbabwe won by 7 runs. The ICC adopted this method officially in 2001.With the changing scoring rates and targets the method was split into professional version and standard version. professional version requires the use of a computer and is more complicated and is used for international levels. while standard version is worked out with a sheet of paper and is used in lower levels of the game.

This method now looks convincing , no it still has some drawbacks. This method does not consider the fact that when you chase a target you try to keep wickets in hand and take lesser risks while scoring, but when the match ends prematurely because of an unexpected shower you would tend to loose because of the slow scoring rate. The par-score of the team batted first would go high.
The second fact which I feel D/L over looks the fact that after it rains the outfield is wet, there is some wind and the bowlers get assistance. The scoring becomes very difficult and the bowling side has undisputed advantage. The resources should consider this fact too.
The third disadvantage of the D/L method is that it does not consider the power play overs and other fielding restrictions. The reduced number of overs and the minimum overs to be played to apply D/L method are decided by the rules agreed before the tournament or the rules layed by ICC. D/L method has no say in rescheduling the number of overs. The power play overs are decided by the ration of overs to be played over fifty. If rain interrupts after the power play, the batting side has taken it's advantage.