Topgrading is considered The Bible of hiring A players.
The methodology uses a behavioural style (Tell me about a time when you... or Describe a situation where you..) to be able to best assess a candidate. One of the core principles is that if a candidate doesn't answer your question directly, you ask it again and probe deeper until you get a real answer. This in-depth probing (zing!) often flusters candidates who aren't prepared to answer these types of questions.