Subtle timing and strategy in long helpmate

Chris J Feather, a master of the helpmate, and a vocal critic of weak compositions, has nothing but praise for the strategy in this long helpmate by Babesi composed in 1955. "The best face of the long helpmate.", he writes in Black to Play - a monograph on helpmates, "Some subtle timing and a more dynamic use of the closed corner than in most such problems. The word 'miracle' used by one solver is hardly out of place. Goodness knows how many hours the genial and charming composer spent on this, but Alybadix" (a computer program to check soundness of fairy compositions) " needed 9 hours, 38 minutes, 3 seconds (with a 80486/33 processor).

Indeed, note how the Black king munches a White pawn creating tempi for the white pawn behind it, as it goes to b4, note how the white knight takes on g4 to create a spare move for white, as black's promoted rook is wheeled into place, and note the precise clockwork timing of everything, and I have passed over mentioning the first bishop underpromotion.