Explaining the D/L method and revised targets

The Duckworth/Lewis system has been around for a while now, but there is still plenty of confusion about how the method works. When Australia's target was increased by just one run, many blamed it on the fact that India lost three wickets in the last over and were bowled out. Had they been only seven down, went the analysis, Australia's target would have been much higher.

As it turns out, this was just another instance of tailenders being blamed for the incompetence of top-order batsmen. What spoilt India's chances of making the D/L rule count in their favour wasn't the fall of wickets at the end, but the fact that they had already lost so many at the time of the interruption.

The D/L system is based on resources available to a team, and in an ODI, both overs and wickets in hand count as resources. A team exhausts all its resources either when it runs out of overs or wickets.

During an interruption, the loss of overs translates into loss of resources for the team, the compensation for which is the extra runs added to the opposition's target. An example makes this easier to understand: let's say India had been 190 for 2 after 38, at which stage rain reduced the contest to 40 overs. The batsmen, who had been pacing their innings for 50 overs, suddenly have just two overs in hand, which is patently unfair to them, and offers the opposition a huge advantage. The increase in the target score is then obviously justified.

However, the potential to utilise the lost overs depends on wickets in hand. At the Gabba, the Indians were already six down at the time of the interruption, which left them with little resources to capitalise on in the five overs which were lost during their innings.

For instance, if India had been 128 for 2, instead of 128 for 6, after 36, and had eventually been bowled out for 194, Australia's target would have been 211. If India had been 128 for 4 at the interruption and then gone on to score 194, Australia's target would have been 205. To think of this intuitively, a team which is denied five overs when they've lost only two wickets has a much greater chance of making those overs count, than a team which is denied five overs when they've already lost eight wickets. The fact that India were bowled out counts for nothing, since their resources would anyway have been exhausted if they had used up all their overs with wickets in hand.

As it turned out, none of this mattered as the rains returned to have the final say later in the evening.