Swingin' in the rain

The irony of the rain rule in limited overs cricket is that the One Day International was itself a product of the rain - Australia and England played the first one when three days of the MCG test in 1971 were washed out. Nonetheless, with early ODIs, rain interruptions and target recalculations were a matter of Class V math. Until the early 1990s, the average run rate (ARR) was used to interpolate targets if rain or any sort of inclement conditions curtailed a match.

...a new method called the Most Productive Overs (MPO) was introduced. The concept was that the team that was chasing would have its target revised based on the runs scored in the most productive overs of the team that batted first.

It all seemed ok, until its unfairness was exposed in the semi final. When rain stopped play with South Africa needing 22 runs off 13 deliveries against England, the resulting recalculation knocked off two of the maiden overs from England's innings and the revised requirement became a ludicrous 22 runs off 1 ball. The MPO looked to have run its course, unwittingly turning a world cup semifinal into a farce.

Prof. Frank Duckworth was listening to the radio commentary of this match and decided to work on something better. His reasoning was that this was a math problem and needed a mathematical approach for a fair solution. In association with another statistician Tony Lewis he developed the Duckworth-Lewis method (or the D/L method, for short) which took the stage of the match and the situation into account when revising targets. The key idea was to focus on how much of their 'resources' a team had remaining.

The method was formally introduced in international cricket in January 1997. Despite the calculations being complicated, it was 'utterly confusing to the ordinary fan but quite fair'.

In 2014, the Duckworth-Lewis method became the Duckworth-Lewis-Stern (DLS) method as Prof Steven Stern took over the custodianship of the method, which requires updates and tweaks to keep up with the changing dynamics of the game. It remains broadly accepted and is perceived as fair even if it is not wildly popular. There have been fringe attempts at alternatives to the DLS method, the most talked about being the VJD method (developed by an engineer from Kerala, V Jayadevan) which even Sunil Gavaskar pitched for at one point.