Rama: In the last round, Spassky gets the chance to make up for his loss to Larsen. Quinones puts up weak resistance.Starting with 9. ... a5, he makes four moves in a row that seal his fate. At any point, ... Bd7, and ... a6, would be simple and good. Instead he becomes impatient and plays 12. ... g5, which might be okay except for 17. ... Bxf3, eliminating the defender of the white squares weakened by the g-pawn's advance.
And why 16. ... cxb6? The whole point of 12. ... g5, was to break the pin and allow the Nf6 to move to d7 and cover the Bb6. By recapturing with the pawn, Quinones faces a lost K+P ending under certain circumstances.
Boris makes it happen, starting with 28. dxe5 ..., opening the file, and continuing with 30. Rd6 ..., which makes exchanges imperative due to numerous threats along the 6th rank.
36. Bxd7 ..., takes off black's last piece, and 37. Kd3 ..., simply and clearly makes his point -- due to favorable King-position white wins by force.
This put Spassky into the Candidate's Matches; first up: Riga and Paul Keres.