The Cocktail
G. H. Hardy on chess problems–
"… the key-move should be followed by a good many variations, each requiring its own individual answer."
(A Mathematician's Apology, Cambridge at the University Press, first edition, 1940)
Brian Harley on chess problems–
"It is quite true that variation play is, in ninety-nine cases out of a hundred, the soul of a problem, or (to put it more materially) the main course of the solver's banquet, but the Key is the cocktail that begins the proceedings, and if it fails in piquancy the following dinner is not so satisfactory as it should be."
(Mate in Two Moves, London, Bell & Sons, first edition, 1931)