The Duckworth-Lewis method of calculating rain-shortened matches provokes strong debate among cricket followers.
There's no ducking the Duckworth-Lewis method. Cricket's much maligned arithmetical solution to a rain-interrupted match remains the best-known way of configuring a shortened match, as has been seen in the Twenty20 World Cup.
What's been good to New Zealand eyes is that the Black Caps have taken into account the fact this tournament is being held in the rainy season and that working knowledge of the Duckworth-Lewis Method (DLM) is an advantage.
When the DLM came into the reckoning against Zimbabwe this week, it was reassuring to see some presence of mind in the dug-out.
Next-man-in Ross Taylor was huddled next to Daniel Vettori as the skipper pored over several pages; working out exactly where the team needed to be after each ball before the rain arrived.
Better that than the situation which stumped Proteas skipper Shaun Pollock when South Africa hosted the World Cup in 2003. His side needed to beat Sri Lanka to reach the super six stage. The game was abandoned with South Africa tied under the DLM because batsman Mark Boucher had been given incorrect instructions before the final downpour.
In Guyana, however, England captain Paul Collingwood wasn't happy over a perceived unfair result in the group stage. England set the West Indies 192 to win off 20 overs, only to have it reduced to 60 runs off six overs with the arrival of rain.
Collingwood claimed such a monster total deserved a monster chase. What he failed to acknowledge was the impact of the West Indies' openers, who reached 30 without loss in 2.2 overs, leaving just 30 required off 3.4 overs when they returned. Had the West Indies lost two wickets before the rain, the target would have been 71.
Duckworth and Lewis have defended the value of their system. They claim that in 70 rain-affected Twenty20 matches since 2002, there has only been one other example where the system has come in for such severe criticism - at the last Twenty20 World Cup when hosts England, again captained by Collingwood, were beaten out of the semifinals, again by the West Indies.
What distinguishes DLM is the fact no one has come up with a more equitable system.
Necessity was the mother of invention thanks to South African Brian McMillan at the SCG against England in the 1992 World Cup semifinal. When the Proteas left the field they needed 22 runs off 13 balls; when they returned, McMillan had to hit the same 22 runs off one delivery. It didn't seem fair.
The creators, Frank Duckworth and Tony Lewis, say the problem is not with the DLM maths - but because the minimum number of overs that officially constitute a Twenty20 match is five. If a match has passed that point when it rains, DLM applies. If they haven't got past five overs - match abandoned.
Many think it becomes a lolly scramble when vital tournament points can potentially be decided over as few as 30 balls.
"If people think that the [England] match was unfair, the question should be asked about the minimum overs," Duckworth told the Guardian this week.
"Rather than look at the DLM, which has to take account of the fact that West Indies were leading at the time the rain came, one might well ask whether five overs is sufficient for a valid match."
In a One-Day International, 20 overs constitute a valid match, 40 per cent of the innings total. In T20 that would be eight rather than five overs.
Many are bamboozled by the DLM but after taking away the logarithms, permutations and pages of charts, the DLM is simply based on past evidence, making it the fairest source to turn to.
Duckworth and Lewis regularly update the charts - inputting match data to adjust for current trends like teams scoring runs at quicker rates. This provides a gauge as to how many runs are needed when there are a certain number of wickets in hand.
Magnifying the problem in this World Cup has been playing in Guyana in the rainy season. Four of the six matches there were affected.
Fortunately there have been no such difficulties so far in Barbados and St Lucia, where the remainder of the tournament will be played.
