What is the best size of follicles to ovulate?

Follicles are minute in size around menstrual days. Slowly they grow and mature. A mature follicle of size more than 16mm is ready to ovulate (release egg). Every follicle in the ovary has the potential to mature and ovulate. However, this seldom happens. Growth of follicles is a complex process, in other words it is a balance between recruitment and senescence of follicles. As a result, some of the follicles grow upto maturity, whereas others decline in the midway.