Know about the Duckworth Lewis(D/L) method, controversial yet reliable to get a result

New Delhi: The first semi- final between Sri Lanka and West Indies which was billed as potboiler had the most unlucky ending when the West Indies team had to accept defeat in the combined effort of the Sri Lankan Bowling and nature's fury to some extent.But it is not the first time that an outcome of an interesting match had to be decided off the field and not by players playing capability but with the help of mathematics and statistical formula.Applied to 50-over matches, each team must face at least 20 overs before D/L can decide the game. In Twenty20 games, each side must face at least five overs.These method was devised by two British statiscians, Frank Duckworth and Tony Lewis. It was first used in international cricket in the second game of the 1996/7 Zimbabwe versus England in an ODI series. which Zimbabwe won by seven runs, and was formally adopted by the ICC in 2001 as the standard method of calculating target scores in rain shortened ODI matches.Various different methods had been used previously, 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. likely loss of wickets, skewing the comparison with the first team.Earlier the "best-scoring overs" method, used in the 1992 Cricket World Cup, left the South Africa requiring 21 runs from one ball (when the maximum score from one ball is generally six runs). Before a brief rain interruption, South Africa was chasing a target of 22 runs from 13 balls but, following the stoppage, the team's amended target became 21 (a reduction of only one run) to be scored off just one ball (a reduction of 12 balls). The D/L method avoids 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.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. It is based on the percentage which is used to calculate a target (sometimes called a '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.Duckworth Lewis keeps the heart beats high when nature interrupts a cricket match. It leads to sudden change in tactics to prevail over the opposition. It has been criticised on the ground that the wickets in hand are much more given weight age in the calculations leading to tactics of not losing wickets when chasing a target. It is also criticised to be very complex and not easily understood.But it still remains to be the best option to decide a curtailed cricket match and continue to spoil sport many a cricket match decisions.