Amaurosis scacchistica

Amaurosis scacchistica (Latin for chess blindness) is the failure of a chess player, during a chess game, to make a normally obvious good move or see a normally obvious danger. The term was coined by Dr. Siegbert Tarrasch. Similar to chess blindness is the Kotov syndrome, in which a player, after a long period of calculation, suddenly makes a move they have not analyzed at all. [Wikipedia]

Sergio Mariotti – N. N.
Simultaneous chess exhibition; Rome, June 29, 1980
Sicilian Defence B94

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6. The sharp Najdorf Variation. 6. Bg5 Nbd7 7. Bc4 e6. “[...] the more common continuation, so what need to play first 6. ... Nbd7?”, wonders International Master Stefano Tatai in his book “Tatai insegna la Najdorf”, Rome, Caissa Italia editore, 2008, p. 20. 8. 0-0 b5? If 8. ... h6?! then 9. Bxf6! Nxf6 10. Bb3 b6 11. f4 Bb7 12. Qd3 Be7 13. Nxe6!± Stean – Browne, 21st Chess Olympiad, Nice 1974. More convincing, however, is 8. ... Qa5(!) 9. Qd2 Be7 10. Rad1 h6 11. Bh4 Ne5 12. Be2! g5 13. Bg3 (Kaplan – Mater, Jerusalem 1967) 13. ... Bd7 14. f4 gxf4 15. Rxf4 0-0-0∞ (R. Marić’s analysis). 9. Bxe6! fxe6 10. Nxe6 Qb6 11. Nd5 Nxd5

12. exd5?? Strange things can happen everywhere! 12. Qxd5 was easy and deadly, for if 12. ... Bb7 then 13. Nc7+! Qxc7 14. Qe6+ and mate next move. 12. ... Ne5 13. Be3 Qb7 14. f4 Nc4 15. Bd4 Bxe6 16. dxe6 0-0-0 17. b3 Nb6 18. f5 Rg8 19. a4 b4 20. Qe2 Be7 21. Rad1 Nd5 22. Kh1 Kb8 23. Bg1?? The “Italian Fury” is going crazy! After 23. Qd2 Nf6 Black stands better, but the game is not yet over. 23. ... Nc3-+ 24. Qf2 Nxd1 25. Rxd1 Rc8 26. Rd4 Rc7 27. Rg4 d5 28. Qg3 Bf6 29. Qd6 Ka8 30. Rxb4 Qc6 31. Qg3 Qc3 32. Qd6 Qc6 ½ : ½. A gallant agreement between the two sides, being Black content of saving the day... his own and that of Grandmaster Mariotti too! Source: Due Alfieri, July-August 1980, p. 157.