In his fourth installment of this video series, Grandmaster Khachiyan brings us a two part lesson: The first being a "blunder fest" between GMs Fischer and Gligoric; and the second being one of the more advanced defensive methods when dealing with an enemy corner pawn. The "Vancura Defense" describes a technique in which the rook can defend by checking laterally -- a very awkward yet effective defensive maneuver. Enjoy!