Bowling Restrictions
In limited overs cricket, there is a limitation on the number of overs each bowler can bowl. This number depends on the match length, and is usually 20% of the total overs in the innings. For example, the usual limit for twenty-over cricket is four overs per bowler, for forty-over cricket eight per bowler and for fifty-over cricket ten per bowler. There is, however, no limit on the number of overs each bowler may bowl in first class cricket matches, except that no two overs can be bowled consecutively thus restricting any one bowler from a maximum of 50% (plus 1 over) of each innings total.
Read more about this topic: Bowling (cricket)