Required run rate equals runs still needed multiplied by six, divided by valid balls remaining. Use the announced winning target, not the opponent's total. If the target is 181 and the chasing team has 121, it needs 60 more runs, not 61.
A chase with an unchanged target
In this hypothetical 20-over innings, the team has 121 after 15.0 overs and the target remains 181. The allocation is 120 valid balls, 90 have been used, and 30 remain. Runs needed are 181 minus 121 = 60. The required rate is 60 × 6 / 30 = 12.00 runs per over.
Keeping balls remaining as an integer avoids the mistake of subtracting overs notation as if it were decimal time.
Two different next-ball outcomes
The following are separate alternatives from the same starting point, not consecutive events.
| Next valid ball | Runs needed | Balls left | Required rate |
|---|---|---|---|
| Dot ball | 60 | 29 | 12.41 |
| Four runs | 56 | 29 | 11.59 |
For the dot-ball branch, calculate 360 / 29. For the four-run branch, calculate 336 / 29. The first increases the pressure represented by the rate; the second reduces it. Neither calculation gives a win probability.
Check target changes before recalculating
After an interruption, use the officially revised target and remaining allocation. Do not reduce the original target in direct proportion to the lost overs and call that a DLS target. A target revision is a separate match calculation; this article only explains the rate once the correct target is known.
A displayed par score and a winning target are not interchangeable. Confirm which field you copied before subtracting the current team score.
When the formula must stop
If no balls remain and runs are still needed, do not divide by zero or print a meaningful-looking finite rate. If the target has been reached, report the chase state rather than a negative required rate. An all-out innings can also end a chase with unused balls; the arithmetic alone does not make those balls available.
Should another run be added to the target? No. A target of 181 already states the total needed to win under the given scenario. Return to the article centre.