In cricket, an over is a set of six consecutive deliveries bowled by the same bowler from one end of the pitch to the batsman at the other end)). After six deliveries, the umpire calls over; the fielding team switches ends, and a different bowler is selected to bowl from the opposite end)). The captain of the fielding team decides which bowler will bowl any given over, and no bowler may bowl two overs in succession)). Although this has not always been so, with overs of four and eight balls used in the past, currently an over must consist of six legal deliveries). If the bowler bowls a wide or a no-ball, that illegal delivery is not counted towards the six-ball tally, and another delivery must be bowled in its place). In theory, an over could continue indefinitely if the bowler continued to bowl wides and no-balls, but it is not common. In Test and first-class cricket, there is no limit to the number of overs in a teams innings, nor is there any limit to how many may be bowled by a single bowler). In these matches, there is a requirement to bowl a minimum of 90 overs in a days play, to ensure a good spectacle, and to prevent the fielding team from wasting time for tactical reasons). The over is a fundamental consideration in the tactical planning of the fielding side, as a single bowler has only six legal balls to bowl before they must hand the ball to another bowler).