Gilmoy: Black sells out in the opening to triple on the weak c4 (Ba6, Nc6-a5, Qd7-c6). It wins a pawn, but the price is too high: the slow-moving Knight gets stranded far from the action, and never moves or contributes again.
With Black essentially a piece down, White offers a Knight, and his Queen twice. Black is trapped between Philidor and Weak Back Rank, and has about as much freedom to respond as a pinata.
Knight: 26 ... Qxg5?? 27. Qf7+ 1-0
27 ... Qf8? 28. Qa2+ 29. Nf7+ 31. Rxf8+ reducing to canonical Philidor 32. Qg8+ etc.
30. Ne5 cleverly defends White's own weak back rank, freeing his Rook to sortie 31 Rf7.
Queen: 34(38). Qxe6?? 35(39) Rxf8 1-0. Both times, Qd8 is Black's only move that protects his own Rook.
37. Nh6 utterly traps Black's King (by denying h6), locking in the Weak Back Rank theme. Clever point 1: It also prevents defending g7 by Rg8. Clever point 2: 36 ... Rxf7? Any upward Rook move exposes Black's weak back rank, hence 37. Qxf6! and Black has three problems: (a) recover Queen, (b) save Rook, (c) defend back rank. Rxf6 loses to (c), gxf6 loses to (b). One move can't cover three flaws!
39. Qe5 threatens mate at g7, and Black can't defend g7 from below. An over-eager Rook trade gets Black's Queen forked, so Black wants a Queen move that also stops mate: 39 ... pin-Q 40. break-pin R-block-g7 and 41. Qe7 is an insidious triple-fork: g7 and d7 (threatening 43. Qc8+), and skewers h7 (hence 42 ... gxh6 becomes impossible). Black's Rook can't save both g7 and either one of d7,c8.