My wife just got her GE and we wanted to test the PreCheck for the first time today; she got the three beeps (approved) but was randomly selected for further screening. We understood that getting expedited screening is not guaranteed at PreCheck as the TSA reserves the right to randomly select the PreCheckers for further screening. It just so happens that my wife got selected on the very first time she used it. Was she just unlucky or the odds are better than 50/50 you get selected for full screening?