The Queen’s squeeze

Yaacov Bleiman – Roberto Cosulich
21st Chess Olympiad Final B; Nice, June 21, 1974
4r3/4b2k/5R2/3p1P1q/pP2p1pP/P5P1/1B2Q2K/8 w - - 0 59

Comments by FIDE Master Israel Gelfer, Positional Chess Handbook, Dover Publications, Inc., Minneola, N. Y., 2001, p. 167.

In this delicately balanced position White surprised Black with the unexpected 59. Qa6!! quickly turning the tables in his favour.
59. ... Rg8. If now 59. ... Bxf6 60. Qxf6 Rg8 61. Qe7+ Kh6 and 62. Bc1+.
60. Qb7! 1–0. The end could be: 60. Qb7! Rg7 61. Rg6! Rf7 62. Qxd5 Qxf5 63. Rg7+.

Autumn Leaves

With regard to the main question of six-time Italian Chess Vice Champion Roberto Cosulich’s presence or absence in Castelvecchio Pascoli, Italy, in the first week of February 1974, Professor Mauro Berni (Genoa, Italy) offered a possible solution which seems most plausible, namely, that “The only explanation seems to me to be that the photo was taken on the 35th Italian Chess Championship at Il Ciocco, October 1–14, 1974. Concomitantly with the Championship, was held a classic eight-round Festival featuring a Master Tournament which was won by Eslon and Cekro. Thus one should explain the presence of Cosulich — who tied with Mariotti for 3rd and 4th prizes in the Championship — in front of the poster in question. See L’Italia Scacchistica, No. 11, November 1974, pp. 349-351”. Photo: Il Ciocco.

Romeo and Juliet

Heinz Schaufelberger – Roberto Cosulich
2nd International Festival; Verona, April 1976
Queen’s Indian Defence E14

1. d4 Nf6 2. Nf3 e6 3. c4 b6 4. e3 Bb7 5. Bd3 Be7 6. 0-0 0-0 7. b3 d5 8. Bb2 dxc4 9. bxc4 c5 10. Nbd2 Nc6 11. Qe2 Qc7 12. Rfd1 Rfd8 13. Rac1 Rac8 14. Bb1 cxd4 15. exd4 Qf4 16. Ne4. International Master Dieter Keller, in his comments for Neue Zürcher Zeitung, No. 123, May 28, 1976, p. 77, suggested 16. Nf1 as better, preventing Black from playing ... Nc6xd4.
16. ... Nxe4. Critical is 16. ... Nxd4 17. Nxd4 Nxe4 18. g3 Qxf2+! (obviously, 18. ... Qe5?? 19. Nc6 loses on the spot) 19. Qxf2 Nxf2 20. Kxf2 Bg5! with unclear but balanced play.
17. Bxe4 Bf6 18. g3 Qg4 19. d5

19. ... Bxb2? This is the decisive mistake. Black should have played 19. ... exd5 20. cxd5 (20. Bxf6 Re8! 21. cxd5 Rxe4 is good for Black) 20. ... Ne5! which, apparently, holds everything together.
20. dxc6 Bxc6. If 20. ... Bxc1 then 21. cxb7 Rxd1+ 22. Qxd1 Rb8 23. Qd7 winning at once.
21. Rxd8+ Rxd8 22. Rd1 Rxd1+ 23. Qxd1. The back-rank mate threats give White easy ways to win the day.
23. ... Bd5! An ingenious trick that at least saves the piece, if not the game.

24. Qa4! Just so. 24. cxd5? Qxe4 25. dxe6 Bf6 26. Qd6 fxe6! 27. Qb8+ Kf7 28. Qxa7+ Kg6 would leave White empty handed.
24. .. b5 25. Qxb5 Ba3 26. Bxd5 exd5 27. Qxd5. Threatening Qd5xf7+. Whether or not Black exchanges Queens, White’s extra Pawn and initiative would win easily in the endgame.
27. ... Qc8 28. Ne5 Qf8 29. Kg2 g6 30. h3 Qe7 31. Nc6 Qb7 32. Qd8+ Kg7 33. Qd4+ Kg8 34. Qd5 Bf8 35. a4 Qb6 36. Ne5 Qc7 37. Nd7 Be7 38. c5 Qd8 39. c6 1–0.

Vanishing Point

He is almost a double of six-time Italian Chess Vice Champion Roberto Cosulich, but the sign in the background that reads “Il Ciocco. Chess ’74. International Festival” raises a question about it, since Cosulich — as far as I know — did not take part in the inaugural International Festival at Il Ciocco International Tourist and Conference Centre in Castelvecchio Pascoli, Italy, on February 2–9, 1974. Can any reader provide more information about it? Photo: Il Ciocco.

To Each His Own

The following game was originally made public by Massimiliano Enzo Maria Orsi on his own website Italian Castling, which features a constantly updated archive of Italian chess history. The game is all the more interesting because it confirms, once again, that Roberto Cosulich was a bête noire to the American Stuart Wagman.

Roberto Cosulich – Stuart Wagman
4th International Open; Rovigo, September 7, 1976
Sicilian Defence B76

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 g6 6. Be3 Bg7 7. Bc4 0-0 8. f3 Nc6 9. Bb3 Bd7 10. Qe2!? Cosulich is already out of the ordinary. 10. Qd2 is mainstream theory.
10. ... a6 11. 0-0-0

11. ... Qc7? The bet worked. The move in the text allows White’s attack to spread its wings and hit hard. 11. ... Na5! 12. Qd3 b5 was satisfactory for Black in Sax – Velimirović, 1st “Tungsram” International Tournament, Budapest 1973.
12. g4 Nxd4 13. Bxd4 e5 14. Be3 Be6 15. h4 b5 16. h5 Bc4. Time did not bring any improvement: 16. ... b4 17. Nd5 Bxd5 18. Bxd5 Nxd5 19. Rxd5 Rfc8 20. Qh2 Bf8 21. Kb1 Rab8 22. f4 Rb7 23. f5 Qc4 24. Qg2 Rbc7 25. Rh2 Rb8 26. Qh1 Rbb7 27. b3 Qc6 28. fxg6 fxg6 29. hxg6 Qe8 30. Rh5 Rg7 31. gxh7+ Rxh7 32. Rd2 Rxh5 33. gxh5 Rh7 34. Rh2 Bg7 35. h6 Bf6 36. Qf1 Rf7 37. Rg2+ Kh7 38. Rf2 Qe6 39. Bg5 Kg6 40. Bxf6 1–0 Starostits – Eusebe, 1st International Open, Angers 2006.
17. Qh2 Rab8 18. Bg5 Rfc8 19. Qh4 Bxb3 20. Bxf6 Bxf6 21. Qxf6 b4 22. h6 Kf8 23. axb3 bxc3 24. Qxd6+ Qxd6 25. Rxd6 cxb2+ 26. Kxb2 1–0. Black’s Pawns fall like ripe pears.

Afloat

Alar Puhm – Roberto Cosulich
International Team Tournament Mediolanum; Milan, February 12, 1974
French Defence C08

1. e4 e6 2. d4 d5 3. Nd2 c5 4. Ngf3 Nf6 5. exd5 exd5 6. Bb5+ Bd7 7. Qe2+ Be7 8. dxc5 0-0 9. Ne5?!

Technically a novelty, but also an incongruent one which throws away the first-move advantage, leaving Black with a symbolic initiative throughout the entire game. Best is the usual 9. Nb3 which Cosulich himself played and met with both colours: Cosulich – Paoli, 3rd International Tournament, Bari 1972, and Paoli – Cosulich, 35th Italian Chess Championship, Castelvecchio Pascoli 1974.
9. ... Re8 10. Nxd7 Nbxd7 11. 0-0 Bxc5 12. Qd1 a6 13. Bd3 Qc7 14. Nb3 Bd6 15. h3 Rad8 16. Nd4 Be5 17. Be3 Nc5 18. c3 Nxd3 19. Qxd3 Ne4 20. Nf3 Bd6 21. Rfe1 Qc6 22. Nd4 Qd7 23. f3 Nc5 24. Qd2 Bc7 25. g4 Ne6 26. Nxe6 fxe6 27. Bf4 Rf8 28. Bxc7 Qxc7 29. Kg2 Rf6 30. Rf1 Rdf8 31. Rae1 Qf7 32. Qd3 h6 ½–½.

It’s a Hard Life

Július Kozma – Roberto Cosulich
International Team Tournament Mediolanum; Milan, February 11, 1974
Nimzo-Indian Defence E43

1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 b6 5. Bd3 Bb7 6. Nf3 Ne4 7. 0-0 f5 8. Qc2 Bxc3 9. bxc3 0-0 10. Ne1. Or else: 10. Nd2 Qh4 11. f3 Nxd2 12. Bxd2 Nc6 13. Rab1 Ne7 14. c5 Bc6 15. cxb6 axb6 16. Rb2 Rf6 17. e4 fxe4 18. Bxe4 Bxe4 19. Qxe4 Qxe4 20. fxe4 Rxf1+ 21. Kxf1 ½–½ Trincardi – Cosulich, 13th New Year’s International Tournament, Reggio Emilia 1970/71.
10. ... c5 11. f3 Nd6 12. e4 fxe4 13. fxe4 Rxf1+ 14. Kxf1 Qh4?! A bit too compromising. 14. ... e5! 15. Nf3 Nf7 gave Black a more than comfortable game in Muir – King, 74th British Chess Championship, Swansea 1987.
15. Nf3 Qg4 16. h3 Qg3

17. Be3?! Here and on the next few moves White might have played something like 17. d5 Nf7 18. Kg1 and consolidated his space advantage. Instead his half measures enable Cosulich to save himself in a drawn endgame.
17. ... Na6 18. Kg1 Rf8 19. Rf1 cxd4 20. Bxd4 Qg6 21. Ne5 Rxf1+ 22. Kxf1 Qh5 23. Qe2 Qxe2+ 24. Kxe2 Nxe4 25. Nxd7 Nec5 26. Nxc5 Nxc5 27. g3 Bg2 28. h4

28. ... Bf1+! 29. Kxf1 Nxd3 30. Ke2 Nc5 31. Ke3. White dares not exchange his Bishop for the Knight, as after 31. Bxc5? bxc5 32. g4 (32. Kf3 h5!) 32. ... h5! the Pawn ending would be lost for him.
31. ... Kf7 32. Be5 Nd7 33. Kd4 Nxe5 34. Kxe5 Ke7 35. g4 g6 36. g5 Kd7 37. c5! Nevertheless, White could also play 37. Kf6 Kd6 38. Kg7 e5 39. Kxh7 e4 40. h5! gxh5! 41. g6 e3 42. g7 e2 43. g8=Q e1=Q 44. Qd8+ Kc6 45. Qc8+ with a draw by perpetual check.
37. ... bxc5 38. c4! The fortress is now unbreakable.
38. ... Ke7 39. Kf4 Kd6 40. Ke4 ½–½.

The Lagoons of Venice

Jan Hendrik Timman – Roberto Cosulich
11th International Tournament; Venice, November 1974
Nimzo-Indian Defence E45

“Cosulich was the best of the Italian masters in this tournament, although many contestants were of the opinion that his youth led him to extremes. For example, look at his draw against Mariotti: 1. P-KR4 P-QR4 2. P-QR4 P-KR4, draw?! And against Timman he played clownishly and lost in six moves by overlooking a piece”, Grandmaster Pál Charles Benkö wrote in Chess Life & Review, Vol. XXX, No. 2, February 1975, p. 81.
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 b6 5. Ne2 Ba6 6. Ng3

6. ... d5?? It’s quite paradoxical that three years before, a game Gligorić – Cosulich, 10th International Tournament, Venice 1971, continued 6. ... Bxc3+ 7. bxc3 d5 8. Ba3 dxc4 9. e4 Qd7 10. Be2 Nc6 11. 0-0 0-0-0 12. Qc2 h5 13. Rfd1 Nb8!? 14. Bc1! h4 15. Nf1 Qc6 16. Bf3 Bb7 17. Bg5 Rdg8 18. d5 Qd6 19. Nd2 Qe5! 20. Bxf6 gxf6 21. Nxc4 Qf4 with satisfactory play for Black.
7. Qa4+ 1–0. “It is a safe bet that this has happened before. Cosulich missed the international master norm at this tournament by half a point” — Kevin John O’Connell, The Batsfod Chess Yearbook, B. T. Batsford Limited, London, 1975, p. 79.

Adijo

Roberto Cosulich – Bruno Parma
10th International Festival; Imperia, September 1968
Sicilian Defence B87

Comments in quotation marks by Grandmaster Enrico Paoli, L’Italia Scacchistica, No. 10, October 1968, p. 243, and International Master Stefano Tatai, Tatai insegna la Najdorf, Caissa Italia editore, Roma, 2008, pp. 162-163.

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Bc4 e6 7. Qe2 b5 8. Bb3 Bb7 9. Bg5 Nbd7 10. 0-0-0. 10. Bxe6!? — “A sacrifice for risk-takers, or, as Steinitz, a staunch advocate of defence, might say, for aspiring suicides”. (Tatai).
10. ... h6. Also good is 10. ... Rc8! 11. Rhe1 h6 12. Bh4 g5 13. Bg3 Rxc3 14. bxc3 Qa5 15. f3 d5 16. exd5 Ba3+ 17. Kd2 Nxd5 18. Bxd5 Bxd5 with excellent compensation for the Exchange, Rossetto – Panno, “YMCA Chess Club” Tournament, Buenos Aires 1968.
11. Bh4 Rc8. 11. ... Qa5 12. Rhe1 g5 13. Bg3 Rc8? 14. e5! Rxc3 15. exf6 Rxb3 16. Nxe6! fxe6 17. Qxe6+ Kd8 18. Bxd6 Bxd6 19. Rxd6 Bc8 20. Red1 1–0 Mariotti – Eppinger, 11th International Festival, Imperia 1969 is an example of the dangers awaiting Black if unacquainted with the theory of the Sicilian. 11. ... g5 12. Bg3 Qb6∞ is an interesting alternative line for Black.
12. f4

12. ... Rxc3! “In such a position, Black needs to keep his cool, but, at the same time, adopt drastic measures, otherwise things will end badly. Hence the sacrifice, which we might now call ‘classic’, is the only possible and promising reaction. The game now becomes truly difficult for both contenders”. (Paoli).
“It is interesting 12. ... g5!? 13. fxg5 hxg5 14. Bxg5 Be7 even though after 15. h4! Rxc3 16. bxc3 Nxe4 17. Bxe7 Qxe7 18. Qe3 White seems to me, albeit slightly, preferable”. (Tatai).
13. bxc3 Qc7. “Now, however, 13. ... g5 can be considered better than on the previous note. To be sure, the complications after 14. e5!? e 14. Nxe6 would make anyone’s hair stand on end”. (Tatai).
14. c4 bxc4 15. Qxc4 Qxc4 16. Bxc4 Nxe4 (Δ ... ... g7-g5)
17. Be1. “Prophylactic, given the threat ... g7-g5 with complications favourable to Black”. (Paoli).
17. ... Be7 18. Rf1 d5 19. Bb3 Ndc5. “Black has only a Pawn for the Exchange, but his position is solid and the White Rooks have no outlets”. (Tatai).
20. Ba5 0-0 21. g3 Bf6 22. c3 Rc8. “It should be noted that both the White Rooks have no open files to occupy at the moment, while the Black unites are ideally placed”. (Paoli).
23. Kb2 Bc6. “The threats are gathering and White is forced to ease up, but he gives up an important and well-placed Knight”. (Paoli).
24. Nxc6 Rxc6 25. Bb4. “After the fall of the Pawn at c3 Black’s compensation will be more than abundant”. (Tatai).
25. ... Nb7 (Δ ... a6-a5)

26. f5. “The return of the Exchange is tempting but incorrect: 26. Rxd5 exd5 27. Bxd5 Rb6! (28. Bxe4 Rxb4+). On the other hand the threat of ... a6-a5 becomes pressing and since there is no defence, White throws himself into the fray”. (Paoli).
26. ... a5 27. fxe6 fxe6 28. Rxf6 gxf6 29. Ba3 Kg7? (29. ... Rxc3!−+)
“It is not well clear why Black did not take on c3 with the Rook (29. ... Nxc3? 30. Rd3 Nb5 31. Rxd5!)”. (Paoli).
30. c4 dxc4 31. Rd7+ Kg6 32. Bc2 Rb6+ 33. Kc1 f5 34. Bxe4 fxe4

35. Rd4? “If 35. Bb2 then 35. ... Nd6. Not 35. ... e3 36. Bd4 e2 37. Kd2”. (Paoli).
White goes on the wrong track. Correct was to centralise the King at once with 35. Kd2 Kf5 36. Ke3 e5 and the ending, albeit somewhat drawish, appears easier to play Black.
35. ... Kf5 36. Rxc4 Nd6 37. Rc5+ Kg4 38. Rxa5 Nc4 39. Ra7 e3 40. Ra4 Rc6 41. Kd1 Kf3 ½–½. “This is the result also given in the ChessBase online database, but it is evident that the final position is easily won for Black”. (Tatai).

K6

Apparently, before leaving England, Roberto Cosulich played (for a penultimate time?) for Middlesex in a match by telephone against a geographically limited representative of Scotland. As reported by the British Chess Magazine, Volume LXXXV, No. 6, June 1965, p. 164, Cosulich, with Black on board four, drew against H[arry?] W[ard?] Richardson:

Middlesex, as County Champion, recently challenged Scotland to a match over eight boards by telephone. Scotland accepted but were unable to bring together a team representing both the East and West, so they called their team West of Scotland. The match, played on May 1st, ended on a 3–3 score with two games unfinished; these were subsequently adjudicated by P. H. Clarke in Scotland’s favour. The detailed results are as follows (Middlesex had White on the odd-numbered boards)— (1) J. Penrose (Middlesex) 1, W. A. Fairhurst (West of Scotland) 0; (2) D. G. Wells (M.) 0, M. Fallone (S.) 1; (3) T. A. Landry (M.) 0, G. Bonner (S.) 1; (4) R. Cosulich (M.) ½, H. W. Richardson (S.) ½; (5) G. Dickson (M.) 1, K. B. McAlpine (S.) 0; (6) R. Fertoszegi (M.) ½, M. J. Freeman (S.) ½; (7) D. Wright (M.) 0, P. M. Jamieson (S.) 1; (8) D. J. Rogers (M.) 0, H. D. Holmes (S.) 1.—Middlesex 3, West of Scotland 5.

Notes from the Sidelines

Roberto Cosulich – Andrea Grinza
36th Italian Chess Championship; Pesaro, June 1975
Caro-Kann Defence B13

1. e4 c6 2. d4 d5 3. exd5 cxd5 4. c4 Nf6 5. c5!?

The Gunderam Variation, a sideline favoured by Grandmaster Sergio Mariotti. White gets a Queenside Pawn majority, but to the detriment of his own development.
5. ... e6. More often Black is caught in the dilemma of having to choose between a Pawn break in the centre and a Pawn break on the Queenside: 5. ... e5!? 6. dxe5 Ne4⩱ Mariotti – Pfleger, 7th International Tournament, Olot 1972 or 5. ... b6 6. b4 e6 7. Be3 bxc5 8. dxc5 a5 9. Qa4+ Nfd7 10. Nd2 Bb7 11. Nb3 axb4 12. Qxb4 Qc7∞ Mariotti – Flesch, 4th Memorial Ivan Parčetić, Sombor 1970.
6. Nc3 b6. Very instructive is 6. ... Be7 7. Nf3 0-0 8. Bd3 b6 9. b4 a5 10. Na4 Nbd7 11. Bf4 axb4 12. c6 Nc5! 13. dxc5 bxc5 and Black’s Pawn roller more than compensates for White’s extra piece, Prins – Richter, Richard Réti Memorial, Trenčianske Teplice 1949.
7. b4 Be7. 7. ... a5 8. Na4 Nfd7 9. Bb5 would give White much more than he dared hope for.
8. Bb5+ Bd7 9. Bf4 0-0 10. Bxd7 Nfxd7 11. Nge2 a5 12. a3 axb4 13. axb4 Rxa1 14. Qxa1 bxc5 15. bxc5. 15. dxc5 gives White two passed Pawns on the Queenside, but Black counterattacks in the centre by 15. ... d4 16. Ne4 Nc6 with a volatile initiative.
15. ... Nc6. 15. ... e5 16. dxe5 d4 17. Nxd4 Nxc5 seems playable enough for Black.
16. 0-0 e5 17. dxe5 (17. Qa4 Qa8=)
17. ... Ndxe5. Also good is 17. ... Nxc5 18. Rd1 d4 19. Be3 Ne6 with equality.
18. Rd1 Bxc5 19. Rxd5 Qe7 20. Bxe5 Nxe5 21. Ne4 Nd7? The losing mistake, leaving Black’s pieces overloaded with impossible defensive tasks. Both 21. ... Ng4! and 21. ... Ng6! merit consideration, so as to reply to 22. N2g3 with 22. ... Qa7! and apparently Black’s just about holding his own.

22. N2g3! Threatens Ng3-f5.
22. ... f6. Or 22. ... g6? 23. Rxd7! winning right off.
23. Qd1! 1–0.

Man on a Raft

When he could, Roberto Cosulich preferred to live where there were seas and ports. And when there was no sea, he would be content with a river. And so, on his way from the Chilean sea to the Mediterranean, he docked his raft on the English shores in 1965.
With the precious help of John Saunders, we succeeded in spotting him here and there around the British docks:

9th Easter Congress — Major A
Southend-on-Sea, April 16–19, 1965

                         1  2  3  4  5  6  Pts
1 WHITBREAD, Alan W.     •  1  ½  ½  1  1   4
2 COSULICH, Roberto      0  •  1  1  1  1   4  
3 ROE, Philip L.         ½  0  •  ½  1  1   3
4 WINSER, William A.     ½  0  ½  •  1  1   3
5 HAWSON, John B.        0  0  0  0  •  1   1
6 HARDER, J. H.          0  0  0  0  0  •   0

16th Ilford Whitsun Congress — Premier Reserves A
Ilford, June 4–7, 1965
As we read on the BritBase website, “The final scores were: (1) Raymond D. Keene 3½; (2) T. Goodhill 3; (3-4) Kenneth W. Lloyd, George W. Wheeler 2½; (5) Andrew J. Whiteley 2; (6) Roberto Cosulich (Santiago, Chile) 1½”.
Even in this case none of his games are given.

Furthermore, a few references to Cosulich playing board seven for Middlesex in the 1964/65 Southern Counties Championship appear on The Monthly News Bulletin of the Southern Counties Chess Union, No. 46, Volume 7, June 1965. Cosulich, with White, first defeated John G. Brogden of Surrey, and then David G. Levens of Leicestershire, leading Middlesex to the Semi-Final match against Chesire which took place on June 12, 1965. “Some of the players on higher boards were well-known (Wade, Hartston, etc.)”, Saunders writes. “He drew his game (playing Black) with Vernon Dilworth. Middlesex qualified for the final but he did not play in that match, so perhaps he left the country at that point”.
It should be noted that the distinguished English amateur Vernon Dilworth was not only the originator of the homonymous variation in the Open Ruy López (1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. 0-0 Nxe4 6. d4 b5 7. Bb3 d5 8. dxe5 Be6 9. c3 Bc5 10. Nbd2 0-0 11. Bc2 Nxf2), but also the proponent of a controversial gambit in the Nimzo-Indian (1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e4).

What Was Left

Pál Charles Benkö – Roberto Cosulich
11th International Tournament; Venice, November 1974
English Opening A29

Notes by Grandmaster Pál Charles Benkö, Chess Life & Review, Vol. XXX, No. 2, February 1975, pp. 81-82, and The Chess Player, No. 7/1974, 883, p. 220.

I had to play Cosulich in the last round, and whether or not he would make the IM norm depended on this game. But for me it was the last chance to improve my standing after my bad luck the previous day.
1. c4 e5 2. g3 Nf6 3. Bg2 Nc6?! (3. ... c6!?)
4. Nf3! White deliberately delays Nb1-c3, since then Black could play ... Bf8-b4 adopting a very popular line today which my opponent played in this tournament. Also, my game with Malich (Skopje 1972) followed that line, which I analyzed in CL&R.
4. ... Bc5 5. 0-0 (5. Nxe5?!)
5. ... 0-0 6. Nc3 d6 7. d3 Bd7 8. e3⩲ Bb4?!

Obviously, Black has not achieved what he wanted with his ... Bf8-c5, so he tries to get back in known lines.
9. Ne2!? Not much advantage was promised by 9. Nd5, e.g. 9. ... Nxd5 10. cxd5 Ne7 and 11. Qb3 to capture the QNP is not recommended.
Also possible was the simple 9. Bd2, but the text move is psychologically better motivated, as Black will have trouble with his KB later.
9. ... e4?! Trying to secure the position of his KB, but now the center is opened advantageously for White.
10. dxe4 Nxe4 11. Qc2 Re8 (11. ... Bf5? 12. Nh4)
12. a3 Bc5 13. b4 Bb6 14. Bb2±

14. ... Qe7?! (14. ... Nxf2!? 15. Kxf2!?)
Black already stands badly since the position of his Knight on e4 is far from secure. On 14. ... Bf5 White could answer 15. Nh4. If the Knight moves away, c4-c5 is menacing. Perhaps Black should have considered 14. ... Nxf2, although White’s two minor piece may prove stronger than Black’s Rook. Even capturing with the King is to be considered after 14. ... Nxf2.
15. Nf4! Black’s Queen does not stand well on e7 because of the weakness of his d5, which explains the following blunder. Black’s entire setup does not meet the demands of the position. Now if 15. ... Nxf2 16. Nd5 wins.
15. ... Nf6? (15. ... f5)
Now Black’s game collapses but his situation was not hopeful anyway.
16. Ng5!+−

Decisively strong, leaving Black no way out. On 16. ... g6, defending against the threats to his h7, 17. Bd5 would have been very strong, e.g. 17. ... Nxd5 18. Nxd5 Qxg5 19. Nf6+ and Black’s Queen is lost. Moreover, on 17. ... Nd8 or 17. ... Rf8 protecting the weak f7, 18. Nxg6 would win easily.
16. ... Ne5 17. Nd5 1–0. After 17. Nd5 Qd8 18. Bxe5 Rxe5 19. Nxf6+ Qxf6 20. Qxh7+ Kf8 21. Qh8+ White will be ahead the Exchange and two Pawns.

Monte Cristo

With the exception of the two Olympiads in which he competed, Roberto Cosulich rarely played outside of Italy. One of these times was when he tore up an invitation to Tunisia.

“The 6th International Tournament in Tunis, to which an Italian Master is invited every year, was narrowly won by the Dutch International Master Ree, the only undefeated player. Tied at second place were Austrian Grandmaster Robatsch and Master Cosulich. The defeat suffered by our representative in the direct clash with Robatsch prevented him from winning the tournament”. L’Italia Scacchistica, No. 5, May 1972, p. 113.

Roberto Cosulich – Slim Bouaziz
6th International Tournament; Tunis, December 1971
Sicilian Defence B51

1. e4 c5 2. Nf3 d6 3. Bb5 Nc6 4. Bxc6 bxc6 5. 0-0 e6 6. e5! d5 7. d3 Ne7 8. c4 Qc7. If 8. ... Ng6 then 9. Nc3 Be7 10. b3 0-0 11. Na4!⩲ Cosulich – Paoli, 13th New Year’s International Tournament, Reggio Emilia 1970/71.
9. Bf4 Ng6 10. Bg3 Be7 11. Nc3 Qb7 12. Na4 Nf8 13. Rc1 Nd7 14. d4 cxd4 15. c5 Qc7 16. Re1 Ba6 17. Nxd4 Rb8

18. Nf5?! A tempting but unsound sacrifice, although at first glance White’s storming attack may seem doomed to success. More systematic is 18. a3 (so as to prevent ... Rb8-b4 and also preparing for b2-b4) 18. ... 0-0 19. f4 leaving White with a clear superiority on both wings.
18. ... exf5 19. e6 f4 20. exd7 Kd8 21. Rxe7. If you say a you must say b.
21. ... Kxe7 22. Bh4 f6. Clearly not 22. ... Kxd7? because of 23. Qg4+ Ke8 24. Qxg7 with too many threats.
23. Qg4

23. ... Kf8? Probably Cosulich was expecting 23. ... Kf7 when 24. Re1 Bd3! gives White hardly anything more than a draw by perpetual check after 25. Qe6+ Kg6 26. Qg4+. But both he and Bouaziz overlooked here the way of coming out of the storm, say 23. ... Qe5!! 24. Qxg7+ Ke6 when White is left with a handful of flies.
24. Re1 Rd8

25. Bxf6! A devastating blow. Bouaziz was still hoping for 25. Re7? Kxe7 26. Qxg7+ Ke6 27. Qxf6+ Kxd7 28. Qf5+ Ke8 29. Qe6+ Kf8 with a draw by perpetual check. The rest is a foregone conclusion.
25. ... gxf6. Neither 25. ... Qxd7 26. Qg5!! nor 25. ... Rxd7 26. Qe6 Qc8 27. Be7+ Ke8 28. Qe5! saves Black.
26. Qe6 Kg7 27. Qg4 Kf8 (27. ... Kh6 28. Re7+−)
28. Qf5 Kf7 (28. ... Qxd7 29. Qxf6+ Kg8 30. Re7+−)
29. Qh5 Kf8 30. Re8 Kg7 31. Re7 1–0.

Trip trap

Roberto Cosulich – Francesco Scafarelli
7th Italian Team Chess Championship; Monticelli Terme, April 1966
Sicilian Defence B56

Notes and punctuation by International Master Francesco Scafarelli, Le mie 50 Siciliane, Editrice Scacchistica Internazionale, Napoli, 1980, p. 50.

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 d6 6. Be3 e5 7. Ndb5 a6 8. Na3 Ng4 9. Nc4! Nxe3 10. Nxe3 Be7 11. Ncd5 Be6 12. c3! 0-0 13. h4 h6 14. g3 b5 15. Bd3 Rb8 16. b4 Re8 17. Qe2 Qc8 18. 0-0 Bd8 19. a4 Qb7 20. axb5 axb5 21. Rfd1 Ne7 22. c4 Nc6 23. cxb5 Nd4 24. Qf1 Qd7 25. f3! Nxb5 26. Bxb5 Rxb5 27. Ra6 Qb7 28. Ra7 Qxa7 29. Qxb5 Kf8 30. Kh1?
Editor’s note: Scafarelli’s question mark is perhaps out of place, but there is no doubt that 30. Kf1 would prevent the next irruption of the Black Queen on f2.
30. ... Be7 31. Rc1 Bxd5 32. Nxd5 Qf2! 33. Qf1 Qxg3 34. b5 Bxh4? (34. ... Qxh4+)
35. b6 Bg5 36. Rc2! Rb8 37. b7

37. ... Qh4+?
Editor’s note: Self-trapping the Queen, but, as two students of the Associazione Culturale “Il Delta della Luna” noted, the correct defence was by no means obvious, i.e, 37. ... Bd8!! (Niccolò & Riccardo), so as to reply to 38. Rc8? with 38. ... Qh4+! 39. Kg2 Rxb7 and it’s Black who wins!
38. Rh2 Qg3 39. Rh3 1–0.

Incredible, but possible

Professor Mauro Berni (Genoa, Italy) shared some pages from a booklet entitled Le mie 50 Siciliane by Francesco Scafarelli that combines history and not always happy endings.

Roberto Cosulich – Francesco Scafarelli
8th Italian Team Chess Championship; Recoaro Terme, May 1967
Sicilian Defence B75

Notes by Scafarelli, Le mie 50 Siciliane, Editrice Scacchistica Internazionale, Napoli, 1980, pp. 40-41 and pp. 49-50.

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 Nc6 6. Bc4 Bd7 7. Be3 g6. Preferable is 7. ... Ng4 8. 0-0 or 8. Nxc6. It is more convenient for Black to submit himself to attack on the f-file by eliminating the e3-Bishop, than to deal with heterogeneous castling.
8. f3! Bg7 9. Qd2. Now White’s position is ideal for attacking on the Kingside.

9. ... Na5 10. Bb3 Nxb3 11. axb3 h5. Preventing g2-g4.
12. h4 a6 13. 0-0-0 Rc8 14. Nd5 Nxd5. Questionable. More interesting is 14. ... Bc6.
15. exd5 0-0. Black cannot abstain himself from castling because of the e-file.
16. g4 Rc5? An oversight in a difficult position after that, as consequence of Black’s castling, the g2-g4 advance regained purpose.
17. Nc6! bxc6. Editor’s note: 17. ... Rxc6! 18. dxc6 Bxc6 seems most acceptable to Black.
18. Bxc5 cxd5. If 18. ... dxc5 19. dxc6!.
19. Be3 d4. Editor’s note: 19. ... hxg4! 20. h5! gxf3 21. hxg6 fxg6 22. Qxd5+ Rf7 23. Bh6 Qf8 24. Bxg7 Qxg7 25. Rd2 Bg4 26. Rdh2 Bh5 is the cold-blooded defence recommended by the mighty engines, but Scafarelli may well be excused for having been afraid of it.
20. Bxd4 Bxd4 21. Qxd4 Qa5 22. Kb1 Rc8 23. Rd3 Qc5. Black is again compelled to simplification.
24. Qxc5 Rxc5 25. Re1 hxg4 26. fxg4 Kf8 27. Rd4 Rc6 28. c4 e5 29. Rxe5? An unnecessary sacrifice.
29. ... dxe5 30. Rxd7 f5! 31. gxf5 gxf5 32. Kc2 Re6 33. c5 f4 34. Rd6! Re7 35. Rxa6 Kg7! 36. Kd2 e4 37. Ra1 Kf6 38. c6 Rc7 39. Rc1 Ke5 40. b4 Kd4 41. b3? (41. b5)
41. ... e3+ 42. Ke2 f3+ 43. Kxf3 Rf7+ 44. Ke2 Rf2+ 45. Ke1 Rg2? (45. ... Rh2!)
46. Rd1+ (46. Kf1!)
46. ... Ke4

Editor’s note: It goes without saying that the ending is an elementary book win for White after 47. Rd8, but...
47. c7?? Kf3 48. Kf1 e2+ 0–1. Incredible, but possible. This also is part of the charm of the game of chess.

Gate to the East

Vladimir Konstantinovich Bagirov – Roberto Cosulich
International Tournament; Naples, December 1977
Nimzo-Indian Defence E30

1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Bg5. The Leningrad Variation, so named because it was in great favour among the players from that city, including also 10th World Chess Champion Boris Vasilievich Spassky.
4. ... h6 5. Bh4 c5 6. d5 Bxc3+ 7. bxc3 d6 8. Nf3 e5. Wikipedia’s popular assessment is open to question: “Black has achieved a Hübner Variation-like blockade, the difference being that White’s dark-squared Bishop is outside the Pawn chain. The pin on the f6-Knight is very annoying, and Black often breaks it by playing the drastic ... g7-g5, which also clamps down on a potential f2-f4 break by White. This move weakens Black’s Kingside, so rather than castle on that side, Black usually safeguards the King by playing ... Ke8-d8-c7”.
9. Nd2 Nbd7 10. e3 Nf8 11. Bd3 Qe7. If 11. ... Ng6 then 12. Bg3 0-0 13. 0-0 Ne7 14. f4! exf4 15. Rxf4 Ng6 16. Rxf6!? Qxf6 17. Ne4 Qd8 18. Nxd6 with enough compensation for the Exchange, Spassky – B. Larsen, USSR vs. Rest of the World, Belgrade 1970.

12. Qb1!? Quite a good idea — even though, years later, White would prefer to play 12. Bxf6! Qxf6 13. 0-0 Qe7! 14. Qc2 Nd7 15. f4 Nf6 16. Rae1 0-0 17. f5 a6 18. Ne4⩲ with a slight edge, Timman – Romanishin, 9th Interpolis Chess Tournament, Tilburg 1985.
12. ... g5 13. Bg3 Rg8 14. Bf5 Ng6 15. a4 Nh5 16. h3?! An unnecessary weakening of the Kingside. White ought either to exchange or retreat his light-squared Bishop, after which the Black King would have to decide whether to go West (... Ke8-d8-c7), or East (... Ke8-f8-g7-h8), with complex play and reciprocal chances in both cases.
16. ... Bxf5 17. Qxf5 Ng7 18. Qb1 f5 19. f3 0-0-0 20. Bf2 Rdf8 21. a5

The rush is on.
21. ... e4! A brilliant positional Pawn sacrifice which vacates the e5-square for the g6-Knight in preparation for a future attack.
22. fxe4 Ne5 23. 0-0? Castling into it. After this mistake, Black’s attack grows irresistible. 23. exf5! still offered White the means to escape the worst: a) 23. ... Nxf5 24. g4 Nf3+! 25. Ke2 (25. Nxf3? Nxe3! would be very bad for White) 25. ... N5d4+! 26. cxd4 Nxd2 27. Qd3 Ne4 (very harsh balanced); or b) 23. ... g4!? (who knows, maybe Cosulich would have played like this) 24. e4 Nxf5! 25. a6! b6 26. exf5 Nd3++ 27. Kf1 Nxf2 28. Kxf2 g3+ 29. Kf3 Qe5 30. Ne4 Rxf5+ 31. K~ Re8 regaining the piece with an easier game to play.

23. ... g4! 24. h4. 24. hxg4 is also answered by 24. ... Nh5! 25. gxh5 Qg5 26. g3 f4! 27. exf4 Rxf4 with a vehement attack.
24. ... Nh5. Threatening ... g4-g3 followed by ... Qe7xh4.
25. a6 b6 26. Be1. Not 26. g3 on account of 26. ... Nf3+ 27. Nxf3 gxf3 28. Kh2 Nxg3! 29. Bxg3 Rxg3! 30. Kxg3 Qg7+ 31. Kxf3 fxe4+ 32. Ke2 (if 32. Kxe4 then 32. ... Qg6+ followed by mate) 32. ... Qg2+ with mate in two.
26. ... g3 27. Rxf5 Qxh4 28. Nf1. White to play and selfmate in three moves: 28. Rxf8+?? Rxf8 29. Nf1? Qh1+! 30. Kxh1 Rxf1#. However, Bagirov can do little or nothing to prevent the final attack.
28. ... Rxf5 29. exf5 Nf6! The bells toll for His Majesty as Black is threatening ... Nf6-e4-f2.
30. Nxg3 Kc7! No illusion is left.
31. Qc2 Nfg4 32. Qe4 Qh2+ 33. Kf1 h5! 34. Ke2 Nf6 35. Qf4 h4 36. Ne4 Qxg2+ 37. Nf2 Rg4 38. Qh6 Ne4 39. Qh7+ Rg7 40. Qxg7+. Desperation, but 40. Qxh4 Qf3+ 41. Kf1 Ng3+ leads to mate in a few moves.
40. ... Qxg7 41. Nxe4 Qg4+ 0–1. In his book Memorabili Battaglie di Scacchi. Un MI ai Raggi X, Le Due Torri, Bologna, 2016, p. 22, International Master Antonio Martorelli, one of the eight participants in the tournament, well recounts the moment when the Soviet Grandmaster surrendered: “Bagirov, disgusted by the outcome of the game, commented: ‘Ah, well, I lost, but this game means just nothing at all to me’. And Cosulich: ‘This victory means nothing to me too!’”.

End of the Line

The following game was published, among others, in The Chess Player, No. 16/1977, (31), p. 12, with annotations by the winner, and once again it is thanks to the good offices of Mr. Dominique Thimognier that it reappears here with brief notes by French chess Master and journalist Sylvain Zinser.

Florin Gheorghiu – Roberto Cosulich
1st International Open; Val Thorens, July 1977
English Opening A28

Notes by Master Sylvain Zinser, Europe Échecs, Nos. 225-226, September-October 1977, p. 297.

1. c4 e5 2. Nc3 Nf6 3. Nf3 Nc6 4. d4. This continuation is now abandoned in favour of 4. g3.
4. ... exd4 5. Nxd4 Bb4. Necessary to prevent or delay e2-e4.
6. Bg5 h6 7. Bh4 Bxc3+. Otherwise White, by Ra1-c1 or Qd1-b3, would avoid the shattering of his Pawn structure with a good game.
8. bxc3 Ne5. 8. ... d6 is more precise, forcing White to reveal his intentions in the centre: e2-e3 or f2-f3 followed by e2-e4. Then the manoeuvre ... Nc6-e5-g6 gains more strength.
9. f4! Ng6. After 9. ... Nxc4 10. e4 Ne3 11. Qe2 Nxf1 12. e5 0-0 13. Nf5 gives White a dangerous attack.
10. Bxf6 Qxf6 11. g3 0-0 12. Bg2 c5. 12. ... d6 13. 0-0 Re8 14. Rb1 c6 15. Qd2 Nf8 16. e4 and White is also better.
13. Nb5 d5?! An attempt to rehabilitate the variation.
14. Qxd5 a6

15. Nd6! A game Chukaev – Buslaev, Riga 1964, continued with 15. Nc7 and Black obtained excellent chances by 15. ... Nxf4 16. gxf4 Qh4+ 17. Kd1 Rd8 18. Nxa8 Be6 19. Nc7 Bxd5 20. Nxd5 Qxf4 etc.
15. ... Qxc3+ 16. Kf2 Bg4 17. Qxc5! Bxe2 18. Qe3! 18. Kxe2? Rae8+! 19. Nxe8 Rxe8+ 20. Kf2 Qb2+! and 21. Kf3? is not possible because of 21. ... Qe2# mate.
18. ... Qb4 19. c5 Bd3 20. Rhc1! Bb5 21. Bxb7 Rab8 22. Rab1 Qa4 23. Bd5 Ne7 24. Bb3 (24. Qxe7 Qd4+ and ... Qd4xd5)
24. ... Qa5 25. Nxb5! Nf5 26. Qd3 axb5 27. Qxf5 Qd2+ 28. Kg1 Qe3+ 29. Kg2 Rbd8 30. Rc2 Rd3 31. Rf1 1–0.

Snow White and the Prince that never came

The following game, played many years ago in the 1st International Open at Val Thorens (France), is not included nor mentioned in public databases, and it’s only thanks to the kindness of Mr. Dominique Thimognier, editor of the excellent website Héritage des Echecs Français, that it appears here.

Jean-Luc Roos – Roberto Cosulich
1st International Open; Val Thorens, July 1977
Sicilian Defence B37

Notes by Grandmaster Bachar Kouatly, Europe Échecs, Nos. 225-226, September-October 1977, p. 298.

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 g6 5. c4 Bg7 6. Nc2 Nf6 7. Nc3 d6 8. Be2 0-0 9. 0-0 Nd7 10. Bg5. A rarely played but interesting move.
10. ... Nc5 11. f3 Be6. More precise was 11. ... Bd7 with the plan ... Ra8-b8, ... a7-a6, ... b7-b5, or the advance ... f7-f5.
12. Qd2 Qa5? 13. Rab1 Bxc3. Weak, but after 13. ... Qd8 14. b4 White is fine.
14. bxc3 Rfc8 15. Nd4 Qc7. Black’s strategy is refuted.
16. Bh6! A move which paves the way for a very strong attack. The weakness of the dark squares becomes now appreciable.
16. ... b6. 16. ... f6 ought to be tried out.
17. Nxe6 fxe6 (17. ... Nxe6 18. f4)

18. f4! Nxe4 19. Qe3 Nc5 20. Bg4 Qd7. If 20. ... Nd8 21. Qd4 wins.
21. f5! exf5 22. Rxf5. On 22. Bxf5 e6 is annoying; if now 22. ... e6 23. Rxc5 followed by Bg4xe6+, or 22. ... gxf5 23. Qg5+ wins.
22. ... Qc7 23. Rbf1 Ne5 24. Rxe5! dxe5 25. Bxc8 Qxc8. If 25. ... Rxc8 26. Qf3! and mate is unavoidable.
26. Qxe5 1–0. If 26. ... Ne6 27. Rf8+ Qxf8 28. Bxf8 Nxf8 29. Qd5+ wins. A pretty game by the French university champion against the runner-up in the Italian championship.

Addio a Lugano

Werner Hug – Roberto Cosulich
Match Switzerland–Italy; Lugano, March 9, 1974
Sicilian Defence B31

Comments in quotation marks by Thurgauer Zeitung, Volume 176, No. 80, April 5, 1974, p. 31.

1. e4 c5 2. Nf3 Nc6 3. Bb5 g6 4. 0-0 Bg7 5. c3 Nf6 6. Re1 0-0 7. h3!? Or 7. d4 at once, on which there can follow 7. ... cxd4 8. cxd4 d5 9. e5 Ne4 10. Nc3 Nxc3 11. bxc3 Qa5? (11. ... Na5!= Hug – Hort, 2nd Gran Torneo Internacional de Ajedrez “Ciudad de Las Palmas de Gran Canaria”, Las Palmas 1973) 12. Qb3 Bg4 13. Nd2 Rfc8 14. h3 Bf5 15. g4 Bc2 16. Qb2 Nd8 17. Qxc2 Qxb5 18. Nb3 Qa4 19. Bg5 Rc7 20. Qd2 Ne6 21. Be3 Rac8 22. Rac1 b6 23. f4 Nd8 24. f5 Qe8 25. Re2 e6 26. f6 Bf8 27. Qe1 Ba3 28. Rcc2 Nb7 29. Bc1 Bf8 30. Bd2 Rc4 31. Qc1 Qa4 32. Bh6 Qa3 33. Qd2 Na5 34. Bxf8 Qxf8 35. Nxa5 bxa5 36. Re1 Qa3 37. Rb1! R4c7? (37. ... Qf8 38. h4 h6 39. Rb7±) 38. Rb4!! Kf8 (38. ... axb4 39. Qh6+−) 39. Rb3 Qa4 40. Qh6+ Ke8 41. Qxh7 Kd8 42. h4 Rd7 43. Rcb2 Qc6 44. Rb8 1–0 Cordovil – Cosulich, 21st Chess Olympiad, Nice 1974.
7. ... Ne8. “The usual move at this point is 7. ... d5. The Knight’s move leads to a transposition of moves”.
In Sydor – Cosulich, 3rd International Tournament, Bari 1972, a draw was agreed after 7. ... d6 8. d4 cxd4 9. cxd4 Qb6 10. Nc3 a6 11. Bf1 Rd8 ½–½. However, 12. Na4 followed by d4-d5 would seem to give White a crushing bind.
8. d4 cxd4 9. cxd4 Nc7 10. Bf1 d5 11. e5 Ne6 12. Nc3 f6. “Consideration should be given to 12. ... a6 in order to keep the Bishop away from b5 and to maintain pressure on d4 and e5”.
13. exf6 exf6. If, instead, 13. ... Bxf6 then 14. Be3 Qd6 15. Rc1 Kh8 16. g3 Bd7 17. Bg2 Rad8 18. Qd2 Bc8 19. b3 Qb4 20. Rcd1 Bg7 21. Qd3 Nc5 22. Qd2 Ne4? (22. ... Ne6) 23. Nxe4 dxe4 24. Ng5 Qxd2 25. Rxd2 Nxd4 (25. ... Bxd4 26. Bxd4+ Nxd4 27. Rxe4⩲) 26. Red1 e5 27. Nxe4 b6 28. Kh1 Bb7 29. Ng5 Bxg2+ 30. Kxg2 Rde8 31. Bxd4 exd4 32. Nf3 Rd8? (32. ... Re4 33. Nxd4? Bxd4 34. Rxd4 Re2=) 33. Nxd4 Bxd4 34. Rxd4 Rxd4 35. Rxd4 Rf7 36. f4 Rc7 37. Kf3 Kg7 38. Ke4 Kf6 39. Rc4 Rd7 40. g4 h6 41. h4 Rd6 42. Rc7 1–0 Ribli – Radojević, 4th Ivan Parčetić Memorial, Sombor 1970.
14. Bb5! Apparently stronger than 14. b3 f5 15. Ba3 Re8 16. Rc1 Bd7 17. Nxd5 Nexd4 18. Rxe8+ Bxe8 19. Nxd4 Bxd4 20. Rxc6 Bxc6 21. Qxd4 Bxd5 22. Bb2 Kf7 23. Bc4 Bxc4 24. Qxc4+ Kf8 25. Qc3 Qd1+ 26. Kh2 Qd6+ 27. g3 Rd8 28. Qg7+ Ke8 29. Bf6 Rd7 30. Qg8+ Qf8 31. Qe6+ Re7 ½–½ Ciocâltea – Ghitescu, International Tournament, Bucharest 1966.
14. ... f5 15. Bxc6 bxc6 16. Na4. “White’s plan is clearly outlined: to occupy the dark squares and, if possible, reduce material until remaining with only a White Knight against Black’s light-squared Bishop”.
16. ... f4 17. b3 Qd6 18. Bb2 Rf5

19. Nc5! “Another step forward to a winning endgame. The Pawn sacrifice is only temporary”.
19. ... Nxc5 20. dxc5 Qf8. “After 20. ... Qxc5 21. Rc1 the White pieces quickly enter the fray”.
As a matter of fact, after 20. ... Qxc5 21. Bxg7 Kxg7 22. Rc1 Qd6 23. Nd4 White’s position is imposing.
21. Bxg7 Kxg7. “Or 21. ... Qxg7 22. Re8+ Rf8 23. Qe1”.
22. Qd4+ Kg8 23. Re2 Bd7 24. Rae1 Re8 25. b4 Rxe2 26. Rxe2 Be8 27. h4 h6 28. Re5 Qf7 29. a4 a6 30. Qb2! “Threatens Qb2-e2 with attack on the e-file. Black is therefore compelled to exchange Rooks on e5”.
30. ... Bd7 31. Qe2 Rxe5 32. Qxe5 Qf5. “This costs a Pawn. But even without this mistake, the game could not have been saved”.
33. Qxf5 Bxf5 34. Ne5 Bc2 35. Nxc6 Bxa4

36. Ne7+? This mistake went unnoticed by the commentator of Thurgauer Zeitung. The winning move was 36. Ne5! Bc2 37. c6 Bf5 38. c7+− with the dual threat of Ne5xg6 and Ne5-c6-a7(e7+).
36. ... Kf7 37. Nxd5 g5 38. hxg5 hxg5 39. Nc7. “Is this Knight going astray?”.
Oh, no. It is already gone.
39. ... Ke7

40. Nxa6! Kd7? A dramatic faux pas. Cosulich overlooks 40. ... Kd8! (instead of 40. ... Kd7?); there might follow 41. b5 (otherwise the Knight is trapped) 41. ... Bxb5 42. Nb4 Ke7 (or any other move with the King) leaving White with a meaningless extra Pawn and a draw in sight.
41. c6+! Kxc6. “The Knight is free, for 41. ... Bxc6 42. Nb8+ and Nb8xc6 yields White an easily winning Pawn endgame”.
If 41. ... Kc8 then 42. Nc5 Bxc6 43. Ne6 winning easily.
42. Nc5 1–0. If 42. ... Bb5 then 43. Ne6 and it is over for Black.