Cricket Statistician Tony Lewis No More

Tony Lewis, one of the men behind the Duckworth-Lewis methodology for deciding the outcome of rain affected limited cricket matches, has died aged 78.

A university lecturer and career academic, he was an unknown mathematician when, 1999, the formula he developed with Frank Duckworth was chosen by the ICC to decide the outcome of matches during that World Cup which had been affected by weather.

In 2014, the model was renamed the Duckworth-Lewis-Stern system, after another statistician, Steven Stern, helped refine and update the methodology.

Lewis first became involved in the project after listening to the commentary on the 1992 World Cup between England and South Africa. The South Africans were chasing down an England total when the rain began to fall. When play resumed, with the system then in use, which saw the lowest scoring overs deducted from a sides innings, South Africa were set the farcical target of needing to score 23 runs off one ball.

That promoted Christopher Marin-Jenkins, the BCC radio commentator, to remark that there should a better system to decide the outcome of cricket matches. Lewis decided to apply his mind to the problem, recognising it as a mathematical problem which required a mathematical solution.

Duckworth, meanwhile, had been working on his own solution, but it had been largely ignored as being too complex. However the turning point came when he explained his thinking at a meeting of the Royal Statistical Society. That came to the notice of Lewis, and the two men started collaborating together.

The Duckworth Lewis method was first used on New Years Day in 1997 in Zimbabwe, when England were chasing 201 in the second ODI. It began to rain and, when play resumed, the visitors were set a revised target of 186 to win, in the end falling short by seven runs.

The methodology differed from previous models in that, not only does it give credit to the ide chasing runs, but it also seeks to recognise the advantages gained by the side defending a total which has taken wickets.

Over the years, the Duckworth-Lewis-method has been criticised because it is difficult to follow, and a chart is needed to plot the progress of each team compared to the other on an over by over basis It also is not best adapted to the playing conditions of Twenty20 cricket, which really took off after the system had been developed.

Despite this, nobody has yet come up with anything better, and it is now used all over the world.