Rational Group Chairman and Chief Executive Officer Mark Scheinberg today announced that Rafi Ashkenazi has joined the Group as Chief Operating Officer and will be responsible for the day-to-day operations of the Group and its brands, including PokerStars and Full Tilt Poker, the two largest online poker sites in the world. Ashkenazi is an experienced gaming industry executive and joins Rational Group from Playtech, a global gaming software company, where he served as COO and board member