Occasionally on a Thursday, when he feels up for it, Magnus Carlsen waltzes into The Good Knight pub in Oslo for their fortnightly contests. He walks past the bar at the entrance, where a beer tap shaped like a knight and another one shaped like a rook welcome visitors. He walks past the stacks of chess books lined up on corners of the pub, and past the many black and white portraits of chess players deep in thought mounted on the walls. He takes his place on any of the 37 tables, each of which has a chessboard inscribed on it. Those Thursday evenings usually end with the world no 1 player winning the fortnightly competitions. Ordinarily, the world’s greatest chess player of the current era winning a game night at his local chess pub would not be news. But Carlsen’s Thursday jaunts are not to play chess. It’s the weekly trivia nights he’s made a habit of winning. “Magnus is a pretty clever guy, not just in chess. There are in fact no chess …