Net run-rate is the common method for differentiating teams level on points in a limited-overs cricket tournament.

It is a formula that measures a team’s average margin of victory, or defeat – a side with several big wins will have a positive net run-rate, while those who have suffered sizeable losses will have a negative one.

To understand net run-rate, you have to first get your head around run-rate.

That’s the average number of runs scored per over by a team in the innings of one match – so, for example, a score of 140 off 20 overs for Team A equals seven runs per over.

Net run-rate is then calculated by subtracting the opposition’s run-rate from the other team’s run-rate.

So if Team B scored 130 off 20 overs, their run-rate would be 6.5 runs per over.

Therefore Team A would emerge from the encounter with a positive net-run rate of 0.500 (7 – 6.5), while Team B would take away one of -0.500 (6.5 – 7).

Once a side has played more than one match in a competition, these figures are calculated cumulatively.

Let’s say Team A scored 160 runs from 20 overs in their next match, then they would have a tournament total of 300 runs, divided by 40 overs – a run-rate of 7.5.

If their second opponents scored 180 runs from 20 overs, we first add that to Team B’s score, making 310 divided by 40 overs – that makes 7.75.

Take 7.75 from 7.5 and Team A end up with a run-rate of -0.25.

Are we done with the calculations now? Well, not quite…

If a team loses and is bowled out early, then we wouldn’t want to divide their score by the overs they played, as that would potentially deliver them a higher run-rate than their opponent.

Therefore if a team is bowled out inside their allotted overs, their run-rate is calculated by dividing their runs by the maximum overs they could have batted.

Got all that?