 Tim Krabbé explains that the pawns on d4 and e4 are blocked "and" pinned, the knight is bound to the defense of e4, the rook is bound to the defense of d4, and the pawn on b4 is bound to the defense of the knight.Krabbé analyzes as best for Black 74...b3!75.Rxd4 Rxd4 76.Rxc3 Rd8 77.Rxb3 Re8 78.Re3 Re5 79.Rc3 (79.Kxf6?