No number of dives will necessarily give a diver the experience required, but more dives is usually better than fewer. Requiring diversity in diving experience is a step in the right direction. Some agencies require it by requiring candidates to have at least 10 dives in each of various conditions such as fresh water, salt water, low visibility (less than 3 feet), night, surf, drift, current, deeper than 80 ft, etc. None of this replaces the instructor trainer's (by whatever name any particular agency might use) judgement.
