Strike rate

The strike rate is a calculation to show the speed at which a batsman scores runs or the frequency at which a bowler takes wickets.
For a batsman, it is a figure of runs 'per hundred balls' faced. That doesn't mean that the batsman has to face one hundred deliveries; it can be calculated at any time. If the striker comes in to bat to face the last ball of the innings, say, and hits it for a boundary 6 he will actually have achieved a strike rate of an incredible 600 runs per hundred balls! To maintain that strike rate would, of course, mean hitting every delivery received in an innings for 6 - and that is most unlikely to happen for more than a ball or two.
Knowledge of batsmen's strike rates is useful in limited-overs matches, since it can help captains decide who to send in to bat in certain situations - when runs are wanted quickly or, perhaps, when a period of quieter consolidation is required.
Strike rate for a bowler is a figure of deliveries per wicket taken. So, if a bowler bowls 13 overs and then finishes the match by taking the last wicket on the fourth ball of his fourteenth over, he would have bowled a total of 82 balls (assuming he didn't bowl any No balls or Wides). If he had taken four wickets in all, his strike rate is 82 divided by the number of wickets he took - 4, which gives the result 20.5. In other words he was taking wickets at a rate of one for every 20.5 balls he bowled.