Generic move factories should really be just a MoveSelector instead.

A MoveFactory is just a user-friendly interface, wrapped by a MoveFactorySelector.

But a true Selector can be made much more powerful:

• randomizeType: NONE, GENERATE_ALL_AND_RANDOMIZE, RANDOM_SELECT_WITHOUT_COMPLETENESS, ...
• terminate aware
• filterable (includes, excludes)
• otherwise configurable

Completeness is the effect that randomly selecting n moves from a selector with n moves will have selected all moves exactly once.