Black discretely cloaks his Queen and attacks the white bishop at c4.
White defends but is forced to retreat the bishop after the Black knight
enters the fray. Black then captures the pawn at f4. Black still has a
limited position, so White castles Queenside and throws down the
gauntlet - will Black castle Kingside without much cover? Leave his King
in the center? Castle Queenside himself? Black temporizes with his
fourteenth move, but eliminates one choice with his fifteenth move.