DUCKWORTH-LEWIS RULE IN CRICKET
Today in India cricket has become so much favorite that even a three year old baby wants to play cricket. Many leagues are starting; people are making great money out of it. But sometimes they are very upset of result of the cricket even they suicide being that much emotional. There was news when India won a match with Pakistan in the World-Cup 1996, a fan of Pakistan made suicide and a man from India died of heart-attack. Have you ever think of a situation, if the decision of the match is in the hand of a single person or a computer. That happens when there comes some natural obstruction in the middle of a match. There is rule naming DUCKWORTH-LEWIS RULE which decides the fate of a team in this situation. The D/L method was devised by two English statisticians, Frank Duckworth and Tony Lewis. Various different methods had been previously used to achieve the same task, including run-rate ratios, the score that the first team had achieved at the same point in their innings, and targets derived by totaling the best scoring overs in the initial innings. All of these methods have flaws that are easily exploitable. For example, run-rate ratios do not account for how many wickets the team batting second have lost, but simply reflect how quickly they were scoring at the point the match was interrupted; thus, if a team felt a rain stoppage was likely, they could attempt to force the scoring rate without regard for the corresponding highly likely loss of wickets, skewing the comparison with the first team. Notoriously, the “best-scoring overs” method, used in the 1992 Cricket World Cup, left the South African cricket team requiring 21 runs from one ball (when the maximum score from any one ball is generally six runs). Prior to a brief rain interruption, South Africa was chasing a target of 22 runs from 13 balls – which was difficult but at least attainable – but the possibility of an exciting conclusion to the game was destroyed when the team’s target was reduced by only one run, to be scored off 12 fewer balls.[3] The D/L method removes – or at least normalizes – this flaw: in this match, the revised D/L target would have been four runs to tie or five to win from the final ball.
It is only applied in the one day 50-50 over match or latest edition of cricket 20-20 match. In the 50-50 over match at least one team should have minimum played 20 over. This is a probabilistically based approach. The essence of the D/L method is ‘resources’. Each team is taken to have two ‘resources’ to use to make as many runs as possible: the number of overs they have to receive; and the number of wickets they have in hand. At any point in any innings, a team’s ability to score more runs depends on the combination of these two resources. Looking at historical scores, there is a very close correspondence between the availability of these resources and a team’s final score, a correspondence which D/L exploits.
Using a published table which gives the percentage of these combined resources remaining for any number of overs, ie. balls left and wickets lost, the target score can be adjusted up or down to reflect the loss of resources to one or both teams when a match is shortened one or more times. This percentage is then used to calculate a target also called as ‘par score’ that is usually a fractional number of runs. If the second team passes the target then the second team is taken to have won the match; if the match ends when the second team has exactly met (but not passed) the target (rounded down to the next integer) then the match is taken to be a tie. Sometime many critical matches get unexpected results causing criticism of this rule. A simple example of the D/L method being applied was the first One Day International (ODI) between India and Pakistan in their 2006 ODI series. India batted first, and were all out in the 49th over for 328. Pakistan, batting second, were 7 wickets down for 311 when bad light stopped play after the 47th over.
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