A rain-affected limited-overs match is rarely abandoned outright. Instead the target is recalculated using a method that treats overs and wickets as a combined resource rather than counting overs alone.
Why simple proportion fails
The obvious approach is to scale the target by the fraction of overs remaining. It is also badly wrong, because runs do not accumulate evenly across an innings.
A side batting first paces itself for a full innings, holding wickets back for a late acceleration. Cutting the second innings short removes the expensive overs and keeps the cheap ones.
Proportional targets therefore hand a large advantage to the chasing side. Correcting that distortion is the entire purpose of a rain rule.
Resources rather than overs
Modern methods treat a batting side as holding a stock of resources determined jointly by overs remaining and wickets in hand. Both dimensions matter, and they interact.
Ten wickets with five overs left is a very different position from two wickets with five overs left, even though the overs are identical.
A published table converts any combination into a percentage of full resources. The revised target is set from the difference between what each side actually had.
Where the numbers come from
The resource values are derived from large samples of completed matches, describing how scoring has historically progressed from each position. They are descriptive rather than theoretical.
Because scoring rates have risen over time, the tables are periodically revised. A method calibrated to an earlier era would understate what a modern side can achieve late.
Different versions exist for different levels of cricket, with the fuller version used in international matches where the highest scores occur.
What the method cannot capture
The calculation knows nothing about conditions. A pitch that deteriorates, an outfield soaked by rain or a ball that swings under floodlights are invisible to it.
It also assumes both sides would have used their resources in an average way, which disadvantages a team whose strength lies in an unusual approach.
Teams accept these limits because the alternative is arbitration by judgement, which would be less predictable and far harder to defend after the fact.
Why matches still get abandoned
A revised target requires a minimum number of overs for each side, commonly twenty in a one-day match. Below that, the sample is considered too small to mean anything.
Tournament regulations then determine what follows, usually a shared result in a group stage or a reserve day in a knockout fixture.
The threshold is a judgement about credibility rather than fairness. A result produced from a handful of overs would be defensible arithmetically and indefensible as cricket.
