have someone's number

Verb

 * 1)  To understand a person's character, capabilities, or situation.
 * 2) * 1994, Marilyn Stasio, "Crime" (review of One for the Money by Janet Evanovich), New York Times, 4 Sept. (retrieved 20 Nov. 2009):
 * Morelli has her number: "Lots of energy, not much control, sexy as hell."
 * Morelli has her number: "Lots of energy, not much control, sexy as hell."