They must have other qualifications, such as good administrative and technical ability and a wide array of knowledge also, but the rest of the Navy must have absolute confidence in those selected. Should the less qualified personnel be selected, there will come a time in battle in which the Navy will fail because of its leadership. Like begets like (e.g., ducks pick ducks), and inadequate personnel, once they have moved up sufficiently to be on a selection board, will themselves be apt to select other inadequate personnel.
Admiral Arleigh A. Burke
Chief of Naval Operations
Interesting article/post from CDR Michael Junge (former CO USS Whidbey Island) on Flag Officer Selection - WHAT DOES A DUCK LOOK LIKE? - Naval Flag Officers In 2002.