Economy rate
Economy rate is the average number of runs conceded per over in cricket. The calculation is (Econ = Runs/Overs bowled). Overs are written as decimals from 0.1 to 0.6, so must be converted into actual decimals (e.g. 0.3 Overs is actually 0.5 as 3 is half of 6) before used in the calculation.
The economy rate is the average number of runs conceded for each over bowled. From the Bowler’s perspective, extras (byes and leg byes) are not counted as runs, hence not added to his tally of runs conceded in an over, but the error balls i.e. a wide and no ball are counted and added to his over, which is displayed in his bowling figure.
The economy rate is more important in one-day cricket and Twenty20 matches than in Test match cricket. The shorter forms of the game (ODI and T20) demand that bowlers (and fielders) restrict the flow of runs from the opposition to give their team a better chance of finishing the game with more runs on the board. In Tests, however, the priority when in the field is to bowl the opposition out and take all ten wickets in both the innings. A bowler's economy rate is normally calculated from their career record, but one might also calculate it for a specific period of time, such as a calendar year or the duration of a World Cup tournament. In one day matches, a career economy rate of less than five runs per over is good. Conceding too many quick runs in a Test match is sure to get you taken off by your captain and replaced with another bowler, while taking a wicket in limited overs matches invariably slows the run rate. Like many aspects of cricket, economy rate vs bowling average vs bowling strike rate is a matter of finding a good balance. In Twenty20 matches, anything under seven runs per over is considered to be good.
Jade Dernbach is at the top of the list of players who have the worst economy rates in One Day International cricket with 6.35 as economy rate.
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