Net run rate

Net run rate (NRR) is a number used in cricket to decide which of two teams is better, if both teams are equal on points gotten from winning games during a competition (i.e. they may have won and lost an equal number of games during a World Cup). It is calculated using the difference between the number of runs scored by a team and its opponents, while dividing each of these by the number of legal deliveries (in batches of 6 i.e. the number of overs) that team and its opponents have each batted throughout all of the games involving that team in the competition. This calculation does not look at how many times each team's batsmen have gotten out, so it gives teams that score many runs very quickly an advantage even if they have more batsmen get out than their opponents.
As an example, if a team wins a game 300 runs to 200, with it having batted 200 legal deliveries (33.2 overs, meaning 33 overs and 2 deliveries, or 33 overs plus a third of an over) and its opponents having batted 185 legal deliveries (30.5 overs), then the team's Net Run Rate during that game is (6*((300/200)-(200/185)))= 2.51.