[Event "Varna Olympiad"] [Site "?"] [Round "0"] [White "Rivera"] [Black "Fischer"] [Result "0-1"] [ECO "E40"] [Opening "Nimzo-Indian: Rubinstein"] 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 d5 5. a3 Bxc3+ 6. bxc3 c5 7. Bd3 dxc4 8. Bxc4 Qc7 9. Bb3 b6 10. Ne2 O-O 11. Bb2 Nc6 12. O-O Na5 13. Ng3 Bb7 14. Rc1 { This loses instructively--White obviously saw Black's next but figured that after 15.f3 he had met the threat, but didn't notice that 14...Qb6 contained a subtler threat.} 14... Qc6 15. f3 Qb5 {The subtler threat of 14... Qb6--White must now lose a bishop, and, though he gives it a try, he can't trap Black's queen.} 16. Ba4 Qxb2 0-1