When there are ungeocoded records, you need to geocode the remaining records interactively.
When geocoding, you might refer to objects whose names are used for other objects that do not interest you. (For example, a city name that is common to two or more states.) To eliminate this problem, refine your search by selecting another column (from, typically, another table). To further refine the search, specify the state for each city, rather than just the city name.