In the game of cricket, an over is a set of six balls, which is bowled from one end of a cricket pitch.
In a normal over, one bowler delivers six balls in an over, from one end of the pitch, to the batsman end. After six deliveries in an over, the umpire who stands on the bowler side, calls ‘over’; the bowling team switches ends, and another bowler is come to bowl an over from the opposite end of the pitch, while the batsmen do not change ends. The captain of the bowling team choose which bowler will bowl now.
An over should consist of six legal deliveries. If the fielding team bowls a wide or a no ball, that is not count in illegal delivery, and bowler bowl extra delivery..
In the occasion that a bowler is injured or hurt, during the middle of an over, a team-mate completes any remaining deliveries by law of cricket.
Because a bowler may not bowl consecutive overs, the general tactic is for the captain to appoint two bowlers to alternate overs from opposite ends. When one bowler tires or becomes ineffective, the captain will replace that bowler with another. The period of time during which a bowler bowls every alternate over is known as a spell.
In restricted overs cricket matches, such as one-day cricket (for example, a One-Day International, “ODI”) and Twenty20 (“T20”), each team has one batting and bowling innings, which end seither all batsmen out or played complete over. In such a match, bowlers are normally limited to the total number of overs they may bowl in a match. The universal rule is that no bowler can bowl more than 20% of the selected overs per innings; thus, in a 50 overs match each bowler can bowl maximum of 10 over in a one day match.
In Test and first class cricket, there is no limit of over for a team, bowler can bowl maximum over in test match. In these matches, there is a requirement to bowl a minimum of ninety overs in a day’s play.