A former spy-catcher for the FBI is helping poker players to read their opponents, it has been reported.
Joseph Navarro has helped the likes of hall-of-famer Phil Helmuth Jr, according to the Associated Press.
He claims to have taken three pages of notes at one of Navarro's seminars.
Mr Navarro argues that "the involuntary non-verbal mannerisms dictated by the brain will always betray the strength or weakness of a player's hand".
He claims that he can work out anyone after just a few minutes and that the tactic of hiding behind sunglasses does not work.
Mr Navarro left his role as a spy-catcher in 2003 but still trains agents from the CIA and FBI in the art.
He has been used by media outlets such as MSNBC in the past as an expert on interrogation techniques and torture.