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ICC consider Duckworth-Lewis replacement

David Hopps
May 30, 2012
The Duckworth-Lewis method has been probed in recent times © Getty Images

The intricacies of the system used to recalculate run targets in rain-affected one-day matches are unfathomable to most people, but the ICC's cricket committee must grapple with the subject at Lord's over the next two days when it is presented with proposals to replace the dreaded D/L method which has been adopted in international cricket in the past 15 years.

The Battle of the Rain Gods might not quite rival the best of Greek mythology - Hollywood is not yet thought to be interested - but it does not lack importance. A World Cup could one day depend on the outcome.

On one side are two reserved statisticians from Lytham St Annes, a peaceful seaside resort on the Lancashire coast, Frank Duckworth and Tony Lewis, whose system has benefited from an ever-increasing amount of data and has gradually won acceptance in cricket circles as making the best of a bad job.

On the other side is a persistent engineer from the southern Indian state of Kerala, V Jayadevan, who has had the audacity to challenge the established order by claiming that the D/L method "comprises several silly mistakes."

In its place, he proposes the alternative that he has worked on tirelessly for the past 15 years - the VJD method. VJD, to British minds at least, sounds disturbingly like the return of Mad Cow Disease, but Jayadevan insists that cricketing sanity is one of the advantages of his system, which has already been trialled in Indian domestic cricket and was also adopted in the now-defunct Indian Cricket League.

The D/L system was eventually introduced in response to a farcical finish to England's World Cup semi-final against South Africa in Johannesburg in 1992 when South Africa resumed after rain to find their target had been reduced to 22 runs from one ball.

There is a sense that Jayadevan's rival system is too much for the ICC to cope with. It took cricket officials years to respond to his letters. One set of rain rules was quite enough. But gradually Jayadevan, a deputy director in the Keralan Engineering Research Institute, won support, notably from the former India captain Sunil Gavaskar.

And so, the ICC annual meeting in Hong Kong last June received his proposals and, doubtless with a grimace, passed them down to the cricket committee at Lord's for their consideration. Dave Richardson, the ICC's chief-executive-in-waiting, has indicated that they will be taken seriously. Clive Lloyd, the former West Indies captain, chairs the committee and played in an era when the response to rain was to turn to the newspaper crossword and put your feet up.

"I wish they get time to go through my views that bring out the anomalies in the D/L method," Jayadevan has told India's Mail Today. "If the members read it, half the job is done.

"The inherent fear of people for mathematics seems to have helped D/L method being questioned beyond a limit. The D/L system comprises several silly mistakes. But somehow it has managed to create an impression in the entire cricket community that it's highly scientific."

The challenge for the ICC, and indeed the cricket public, is to go beyond nationalistic rivalries, judge the stringency of two complex systems and calculate the benefits they can bring to the game. There are differences and a few can be outlined in laymen's terms.

The battle between Duckworth and Lewis on one hand and Jayadevan on the other has been characterised as a battle between mathematics and engineering. The mathematician pins faith in the purity of the mathematical algorithm; the engineer is prepared to put more emphasis on the evidence of what works.

In other words, Jayadevan will adopt what one specialist called "intelligent use of trial and error" if it produces a better outcome.

To add to the debate that is raging in statistical circles, the view is growing that Twenty20 behaves very differently from ODIs and requires its own separate tables.

"Like in cricket, the ultimate result of a stroke is more important than how it is played," Jayadevan said. "The most important point regarding the acceptability of a method is its reasonability to adjust targets in a truncated match, and here my system is far ahead. A majority of cricketers and officials are looking for a change and hence it makes sense to give an opportunity to VJD system at least for the next two years."

Both systems recalculate a rain-reduced target based on the number of overs faced and the number of wickets remaining - described as the "resources" still available. There are, however, key differences.

Firstly, the D/L method relies upon a pure mathematical curve that assumes a team's scoring rate accelerates throughout a team's innings. Jayadevan argues that this is no longer the case because of fielding restrictions in the early overs which cause a rush of early scoring before mid-innings consolidation. His tables are adjusted empirically to take this into account. He even claims to take Powerplays into account.

Secondly, and this is where it gets difficult, the D/L method relies upon a single curve which is used to make adjustments to the target. Jayadevan uses two curves: a normal curve to adjust runs already scored, and a target curve to adjust runs still to be scored. The normal curve takes note of both runs scored and wickets lost, but the target curve takes note of only runs remaining.

The greater complexity of Jayadevan's system is less of a problem than it once was. Both methods are computer-based. Calculations are no longer made on the back of an envelope. In theory at least, you can just key in the match details and await the printout.

David Hopps is the UK editor of ESPNcricinfo

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