Net run rate (NRR)

Net run rate (NRR) is a team's overall run rate across a tournament minus the run rate it has conceded, used to separate teams level on points.

The formula is:

NRR = (runs scored / overs faced) - (runs conceded / overs bowled)

Both halves are totals over the whole tournament, not an average of individual matches. A side that has scored 640 runs from 80 overs and conceded 600 from 80 has an NRR of 8.00 minus 7.50, or +0.500.

The rule that catches people out is that a team bowled out is treated as having faced its full quota of overs. Get all out for 120 in 15 overs of a T20 and your run rate for that innings is 120 divided by 20, not by 15. The same applies to the opposition when you bowl them out. That is why bowling a side out is worth more to the table than restricting them, and why a chasing team that has already won still hurries to finish: every over saved in a chase is added straight to the numerator side of the sum. In rain-affected matches, the DLS-adjusted figures are used.

NRR decides places on the points table, and therefore who gets the second chance in the playoffs, more often than any other tiebreaker.

In Masterstroke: the league table shows net run rate next to points, and the board is well aware of it when it reviews your season.