Part 4 of the series highlighting the mastery of GM Bent Larsen. The Danish great starts out with a bluff in the opening - a pawn sac which wasn't accepted. He then achieves the better end of an opposite-colored bishop middlegame, punctuated by the rook sac Rb5! which cannot be accepted. Larsen geometrically forms multiple mates on the dark squares, and even throws in a possible underpromotion to finish things off.