Half note

Stockfish – Pedone

Top Chess Engine Championship Season 19 — FRC2 Semileague 1; tcec-chess.com, November 19, 2020

rkqnbnrb/pppppppp/8/8/8/8/PPPPPPPP/RKQNBNRB w GAga - 0 1

Position #715

1. d4 d5 2. g4 g5 3. e3 e6. Holding on to the symmetry as long as possible, but 3. ... Bc6 also came into consideration, in order to reply to 4. c4 with 4. ... dxc4 5. Bxc6 Nxc6 6. Qxc4 Qe8 followed by a-side castling (... 0-0-0). 4. c4 f6 (4. ... dxc4!? 5. Qxc4 Nd7) 5. a3 dxc4 6. Qxc4 h5?! The immediate ... Nf8-d7-b6 seems more to the point. 7. h3 hxg4 8. hxg4

8. ... Nf7? 8. ... Nd7 was still Black’s best play and probably the last opportunity of coordinating its development plans; after 9. Nc3 Nb6 10. Qb3 a5 11. Ng3 Bg7 12. 0-0-0 Bf8 13. Kb1 Nc6 White stands better but Black has its fighting chances (14. d5 Nb4!?). 9. Ba5! Nd6 10. Qb3! Nd7 11. Nc3 Nb6 12. Bb4 Qd7?!

13. Bxd6! cxd6 14. a4 Bg6+ 15. e4 0-0-0. 15. ... d5 is equally met by 16. Ne3 with a crushing bind — moreover, White can still castle on both wings. 16. Ne3 Kb8 17. a5 Na8. 17. ... Nc8 does not make much difference as after 18. Ra4 d5 19. Ka2 White’s attack develops easily and smoothly. 18. Ra4 Nc7 19. a6 b6 20. Nc4 Na8. After 20. ... Nd5 21. Nxd5 exd5 22. Nxb6! everything falls apart. 21. d5! Rc8 22. Rd1 e5 23. Na5 Bf7 24. Bf3 Nc7 25. Be2 Ka8 26. Rc1 Be8 27. Rb4 Qd8 28. Na4. Threatening to take on b6 either with the Rook or with the Knight. 28. ... Bxa4 29. Qxa4 Qe8

30. Qb3! Rg7. Or 30. ... bxa5 31. Rb7+− with the threat of 32. Rxa7+ Kxa7 33. Qb7# 31. Rbc4 Rh7 32. R4c3 Kb8 33. Bb5 Nxa6. Desperation, but if 33. ... Qf7 then 34. Qc4 forcing mate in a few moves. 34. Bxa6 Rc5 35. Rxc5 dxc5 36. d6 Rc7 37. Qd5 Qd7 38. Rd1 Rc8 39. Bxc8 Qxc8 40. d7 Qxd7 41. Qxd7 bxa5 42. Qe7 a4 43. Rd8# 1 : 0.

Two Halves

Stockfish – Stoofvlees

Top Chess Engine Championship Season 20 — FRC3 Final League; tcec-chess.com, March 14, 2021

rqkbbnnr/pppppppp/8/8/8/8/PPPPPPPP/RQKBBNNR w HAha - 0 1

Position #697

1. d4 d5 2. c4 dxc4 3. Ne3 c5 4. dxc5 Nf6. Here the alternative was to maintain the symmetry with 4. ... Ne6 (5. Nf3 Nf6), but in any case the text, though not strictly symmetrical, is not too asymmetrical either. Black temporarily sacrifices a Pawn to keep development going. 5. Qc2 Ne6 6. Qxc4 Qe5 7. Bb4. Yet it is not too surprising that a machine wants to hold on to its material advantage. 7. ... a5 8. Ba3 Bc7 9. Nf3 Qh5. Also worth considering was 9. ... Qf4 followed by a-side castling (0-0-0) — whether before or after the exchange of Queens is irrelevant. 10. g4! Qh6

11. g5! Only thus. If, instead, 11. h4? then 11. ... Qf4! 12. Qxf4 Bxf4 13. Nd2 0-0-0! with powerful advantage. 11. ... Nxg5 12. Nf5 Qh3 13. Nxe7+ Kb8 14. c6! After 14. Nxg5 Qg2 Black wins back the Knight with good play for the Pawn. 14. ... Ra6. Not 14. ... b6?? because of 15. Nxg5 Qg2 16. Qb5! Qxh1 17. Bd6! winning immediately. 15. cxb7 Rb6 16. Nxg5 Qg2 17. Re1 Qxg5+ 18. e3

18. ... Bb5! Probably the only move. Black gives up a third Pawn in order to keep his chances of survival as high as possible. Incidentally, Black could not take on b7 either with the King or with the Rook on account of White’s Bishop going to f3. 19. Qxf7

19. ... Bd6? But Black eventually goes astray. 19. ... Rd8! was the consistent corollary of its previous move, since after 20. Bb3 (20. Bf3 should not worry Black too much after 20. ... Qh4) 20. ... Be2! 21. 0-0-0 Bxd1 22. Rxd1 Qb5!∞ it is anything but clear how White can make any progress. 20. Bxd6+ Rxd6 21. Bc2 Bd7? There’s something tremendously human about Black’s last error. ⌓ 21. ... Rd7! still gave some chances of putting up a defence. 22. h4 Qg2 23. Qc4 Re6 24. 0-0-0! A most powerful developing move! The rest is simply technique. 24. ... Qxb7 25. Rd3 Rb6 26. Red1 Re8 27. Nd5 Rc6 28. Qf4+ Ka8 29. Rb3 Nxd5 30. Rxb7 Nxf4 31. Rdxd7 Nd3+ 32. Kb1 Nc5 33. Ra7+ Kb8 34. Rxg7 Rd8 35. a3 Rd2 36. Rxa5 Rxf2 37. Rb5+ Ka8 38. Rg4 Rf1+ 39. Ka2 Rf7 40. Rc4 Rfc7 41. Bxh7 Rxh7 42. Rcxc5 Re6 43. Rc4 Ra6 44. Rcb4 Re7 45. h5 Rh7 46. e4 Rb7 47. Rxb7 Rxa3+ 48. Kb1 Ra1+ 49. Kc2 Rc1+ 50. Kd3 Rc3+ 51. Kd4 Rd3+ 52. Kc5 Rd5+ 53. Kb6 Rd6+ 54. Kb5 Rd1 55. Rb6 Rc1 56. Ra4# 1 : 0.

Titus Andronicus

Stockfish – Revenge

Top Chess Engine Championship Season 21 — FRC4 League C; tcec-chess.com, December 27, 2021

nqrbnkbr/pppppppp/8/8/8/8/PPPPPPPP/NQRBNKBR w HChc - 0 1

Position #125

1. b4 b5 2. a4 c6. If 2. ... bxa4 then 3. c4 regaining the Pawn with an edge. 3. a5 h5 4. c3 Bh7 5. Bc2 Bxc2 6. Naxc2 c5 7. h4 cxb4 8. cxb4 0-0 9. f3 Nd6 10. Ne3 Nc4 11. Nxc4 bxc4

12. g4! hxg4 13. h5! The pointe of the previous move, whereas 13. fxg4 f5! might give rise to undesired effects.

13. ... e6? This seems to be a loss of time. Black might play 13. ... f5 at once — and if 14. Be3 then 14. ... d5 15. h6 g6 16. h7+ Kh8 17. Rh6 (if 17. Ng2 now Black would reply 17. ... e5) 17. ... Rc6 18. b5 Rcf6 19. Bg5 R6f7 20. Ng2 e5 21. Rxg6 Bxg5 22. Rxg5 Nc7! 23. Nh4 Qd8 24. f4 Ne6 with a tenable defence. 14. Be3 f5 15. h6 g6. All the same, 15. ... Bf6 16. fxg4 fxg4 17. Kg2 leaves White with a powerful attack. 16. h7+ Kh8 17. Ng2. With the threat of Ng2-f4. 17. ... e5 (17. ... g5 18. f4!) 18. fxg4 d5. This quickly leads to to an unsustainable situation, but it is not easy to suggest a better move. If 18. ... f4 there may follow 19. Bf2 g5?! (or 19. ... Kg7? 20. h8=Q+! Rxh8 21. Rxh8 Kxh8 22. Qxg6 threatening both Rc1-c3 and 0-0-0 with mate coming) 20. Rh6 with a crushing preponderance. 19. Bc5 Rf7 20. Kg1 Rc6 21. gxf5 gxf5 22. Kf2. Making room for the c1-Rook on the g-file. 22. ... e4 23. Rcg1 Rg7 (23. ... Rxh7 24. Bd4+ Bf6 25. Qa1+−) 24. Rh3 c3 25. e3 Rh6! Humanly speaking, it’s just a last-ditch trick.

26. Nf4! Of course not 26. Rxh6?? on account of 26. ... Qg3+ and Black has at least a perpetual check. The rest is relatively easy: 26. ... Bh4+ 27. Ke2 Rg4 28. dxc3 Kxh7 29. Rgh1 Qg8 30. Kd2 Nc7 31. Kc2 Ne6 32. Nxe6 Qxe6 33. R3h2 Kg8 34. Bxa7 f4 35. Bd4 f3 36. b5 Kf7 37. a6 Rg2+ 38. Rxg2 fxg2 39. Rg1 Qg4 40. Qd1 Qxd1+ 41. Kxd1 Bf6 42. Rxg2 Rh1+ 43. Kc2 Ra1 44. Kb3 Be7 45. Ra2 Rb1+ 46. Ka4 Rg1 47. b6 Bd8 48. b7 Rg6 49. a7 Ra6+ 50. Kb3 Rxa2 51. Kxa2 Bc7 52. a8=Q Bd6 53. Qc8 Kg6 54. Qg4+ Kf7 55. Qf5+ Ke7 56. Bc5 Bxc5 57. b8=Q Bxe3 58. Qbf8# 1 : 0.

An Anthropology of Machines

Stockfish – Cheng

Top Chess Engine Championship Season 21 — FRC4 League C; tcec-chess.com, December 28, 2021

bqrknrnb/pppppppp/8/8/8/8/PPPPPPPP/BQRKNRNB w FCfc - 0 1

Position #771

1. b4 d5 2. c4 dxc4 3. Rxc4 Ngf6 4. Ngf3 Nd6 5. Rc1 b5. 5. ... 0-0 6. Ne5 leads to similar, if not identical, variations as in the actual game. 6. Ne5 Qb6 7. N1d3 0-0

8. g4!→ Bxh1 9. Rxh1 Rfd8 10. g5 Nfe4 11. Rc6 Qb7. If 11. ... Nxf2+ then 12. Ke1! Nxd3+ 13. Qxd3 Qb7 14. Qf3 Rf8 15. h4! with irresistible attack (in fact, Black cannot do anything against the threat of h4-h5 followed by g5-g6). 12. f3 Nxg5 13. Rg1 Ne6 14. Nc5 Nxc5 15. Rxc5. White gave up a Pawn, but obtained in return a terrific attack against the crumbling Black castle. 15. ... Qa6. Improvising a defence on the sixth rank. 16. Nc6 Rd7. Of course it’s not a good idea taking away the e8-square from the Black Knight: 16. ... Re8?? 17. Bxg7! Bxg7 18. Rcg5 with mate coming.

17. Ke1! e6 (17. ... g6? 18. Bxh8 Kxh8 19. Ne5 Rdd8 20. Nxg6+! hxg6 21. Rxg6! fxg6 22. Qxg6+−) 18. Qb2. Threatening Rg1xg7+ followed by mate in two. 18. ... f5 19. h4 Nb7 20. Rc1 Nd8 21. Qb3 Qa4 (21. ... Nxc6? 22. Qxe6+ Rf7 23. Rxc6 Qb7 24. h5+−)

22. Qe3! White gives up a second Pawn in order to carry out the final attack. 22. ... Qxa2 23. Ne5 Re7 24. Qg5 Kf8 25. Qh5 Kg8 26. Nd7! (Δ Nd7-f6+) 26. ... Rf7 (26. ... Rxd7?? 27. Qe8#) 27. Kf2! With the threat of Ba1xg7. 27. ... e5. Black has no other move to avoid immediate disaster, but the price is very much high also. 28. Nxe5 Qe6

29. Rg6! Qe8 30. Nxf7 Qxf7 (30. ... Nxf7? 31. Rxg7+!+−) 31. Rg5 Qxh5. Black can find nothing better than a theoretically lost ending, for if 31. ... g6? then 32. Rxg6+! winning even more easily. 32. Rxh5 g6 33. Rg5 Ne6 34. Rgg1 Nd4 35. Bc3 Bf6 36. Rh1 Kf7 37. e3 Nb3 38. Rb1 Bxc3 39. dxc3 Nd2 40. Rbd1 Nc4 41. Rd7+ Kg8 42. Rhd1 Nb6 43. Rd8+ Rxd8 44. Rxd8+ Kf7 45. Rh8 Nd5 46. Rxh7+ Kf6 47. e4 Nxc3 48. Rxc7 Na2 49. Rxa7 Nxb4 50. exf5 gxf5 51. Rb7 Nd5 52. h5 Kg5 53. Rxb5 Nf6 54. h6 Kxh6 1 : 0. Unplugging the plug as the position after 55. Rxf5 is a book win.

Number Story

Stockfish – Critter

Top Chess Engine Championship Season 21 — FRC4 League C; tcec-chess.com, December 28, 2021

rkbnnrqb/pppppppp/8/8/8/8/PPPPPPPP/RKBNNRQB w FAfa - 0 1

Position #759

1. g4 g6 2. a4 d6 3. a5 a6 4. f4 f5 5. g5 e5 6. fxe5 dxe5 7. Nd3 Ne6 (7. ... e4 8. Nc5 Ne6 9. Ra4⩲) 8. Bd5 Nd6 9. Nc5 Rd8 10. d3 Qe8 11. Bxe6 Bxe6 12. Ra4

12. ... Bc8? An unnecessary prophylaxis that overdefends b7 but leaves the h7-Pawn vulnerable. Much better seems 12. ... Bg8! to which might follow 13. c4 Bg7 14. Rb4 Nb5! 15. cxb5 axb5 16. a6! b6! 17. Nc3 bxc5 18. Qxc5 Bf8 19. Qxb5+ Qxb5 20. Rxb5+ Kc8 21. Ra5 Bb4! 22. Rxe5 Rxa6 with a possible equality, Black’s two Bishops compensating for its minus Pawn. 13. Rh4± Qe7 14. Bd2 f4 15. Bb4 Qg7 16. e4 Nb5 17. Nc3 h5 18. Nd5 Nd4 19. c4 Nc6. 19. ... c6 20. Nb6 Qc7 does not appear appealing either, provided of course White abstains itself from winning the Exchange. 20. Bc3 Qf8 21. b4 Qg8 22. Qg2 Qf7

23. d4! Black’s centre disintegrates. 23. ... exd4 24. Rhxf4 Qg8 25. Be1! Be5 26. Bg3 Bd6. Or 26. ... Bxf4 27. Bxf4 with the fatal threat of 28. Bxc7+ Ka7 29. b5 axb5 30. cxb5 Rb8 31. Bb6+ Ka8 32. Nc7#. 27. Rf7 h4 28. Bf4 Rf8 (28. ... Qxf7 29. Bxd6+−) 29. Rxf8 Qxf8 30. Bxd6 Qxd6 31. Rf6 h3 32. Qd2 Qd8 33. Rf7 Qh8 34. Rxc7 Qf8

35. Rxb7+! Bxb7 36. Nd7+ Ka7 37. Nxf8 Rxf8 38. b5 Ka8 39. bxc6 Rf1+ 40. Kb2 Bxc6 41. Qxd4 Rf7 42. Nb6+ Ka7 43. Kc3 Rh7 44. Qd8 Bb7 45. Nd7 Rxd7. Black has no other move. 46. Qxd7 Kb8 47. Kb4 Bc8 48. Qe7 Be6 49. Kc5 Bg4 50. Kb6 Bd7 51. Qxd7 Ka8 52. Qa7# 1 : 0.

Cheeseboard

Stockfish – Cheese

Top Chess Engine Championship Season 21 — FRC4 Testing; tcec-chess.com, December 15, 2021

qrkbbnnr/pppppppp/8/8/8/8/PPPPPPPP/QRKBBNNR w HBhb - 0 1

Position #681

1. e4 e5 2. b4 Bf6 3. Ne3

3. ... 0-0-0? It is only three moves and two moves, and Cheese already commits a grave strategic misplay which leaves White with a free hand all over the board. Any sound developing move was better, including perhaps the symmetrical 3. ... b5!? which after, say, 4. a4! Qxe4 (⌓ 4. ... a6) 5. Bf3 can give rise to complicated and interesting play – with the initiative in White’s hands. 4. d3 d6 5. a4 Ne6 6. Nf3 Bd7 7. b5 Kb8 8. a5 Ne7 9. Bd2 Rhg8 10. h4

10. ... a6? It’s very clear that this means absolute surrender. ⌓ 10. ... b6 was a much lesser evil. 11. b6+− c5 12. g4 g6 13. Nd5 Nxd5 14. exd5 Nd4 15. Nxd4 exd4 (15. ... cxd4 16. Qa3+−) 16. Bf4 Be5 (16. ... Be7 17. Rhe1 Bf8 18. c3+−) 17. Bxe5 dxe5 18. Qa3 Rc8 19. g5 h6 20. Re1 hxg5 21. hxg5 Rgd8. A useless Pawn sacrifice, but no better is 21. ... Rge8 because of 22. f4!+− putting Black into a zugzwang. 22. Rxe5 Bb5 23. Bg4 Bd7 24. Bxd7 Rxd7 25. Qa4

25. ... Rdd8. Not 25. ... Rcd8?? on account of 26. Qxd7! forcing mate in two moves. 26. d6! Rxd6 (26. ... Rc6 27. d7!+−) 27. Qe8 f6 28. Qe7 Rdc6 29. Rd5 R6c7 30. Rd7 c4 31. bxc7+ Rxc7 32. Rxc7 fxg5 33. Rcxb7+ Kc8 34. Qc7# 1 : 0.

A Random Interlude

Stockfish – Ethereal

Top Chess Engine Championship Season 21 — FRC4 League C; tcec-chess.com, December 26, 2021

nrnkbbqr/pppppppp/8/8/8/8/PPPPPPPP/NRNKBBQR w HBhb - 0 1

Position #170

1. e4 Nab6 2. Nab3 f6 3. d4 d5 4. exd5 Nd6 5. Nd3 Nxd5 6. 0-0-0 b6 7. h4 a5 8. Kb1 h5 9. g3 Bd7 10. f3 Bf5 11. Rh2 a4

12. Nbc5 Nc4 13. g4 bxc5 14. gxf5 Nce3

15. dxc5 Nxd1 16. Nb4 Nxb4 17. Bxb4 0-0-0 18. Ba6+ Kb8

19. c6 Nc3+ 20. Bxc3 e5 21. Qf1 Bc5 22. a3 Qd5 23. Qb5+ Bb6 24. Qxa4 Qxf3 25. Ka2 Qxf5 26. Bb4 e4 27. Bb7 Ba7 28. Rh3 Rd1 29. Rb3 Qf1 30. Rc3 Ra1+ 31. Kb3 Qb1 32. Qa6 Ra2 33. Ka4 Rxb2 34. Rc4 Qg1

35. Bc5 Rb6 36. Qxa7+ Kxa7 37. Bxg1 Re8 38. Be3 f5 39. Rc5 Kb8 40. Rxf5 Rxb7 41. cxb7 Kxb7 42. Kb4 g6 43. Rf6 Rd8 44. a4 Rd1 45. a5 Rb1+ 46. Kc4 Kc8 47. a6 Kd7 48. a7 Ra1 49. Rxg6 c6 50. Rg8 Ra4+ 51. Kb3 Ra5 52. a8=Q Rxa8 53. Rxa8 Ke7 54. Ra5 Kf6 55. Rxh5 Kg7 56. Rg5+ Kf7 57. h5 c5 58. h6 Ke6 59. h7 Kd6 60. h8=Q Kd7 61. Qh7+ 62. Rg6+ Kb5 63. Qb7+ Ka5 64. Qb6# 1 : 0.

Lost in the Shuffle

Stockfish – Leela Chess Zero

Top Chess Engine Championship Season 21 — FRC4 Final; match game 6; tcec-chess.com, January 5, 2022

bbrqknrn/pppppppp/8/8/8/8/PPPPPPPP/BBRQKNRN w GCgc - 0 1

Position #784

1. c4 Nfg6 2. c5 b6 3. b4 a5 4. Qa4 e6 5. g4 Qh4

6. Nhg3 Qxg4 7. Qb5 Bb7 8. bxa5 Bc6 9. Qa6 Rd8 10. cxb6 Qb4 11. Bd3 cxb6 12. Qxb6 Qxb6 13. axb6 f5

14. Bc4 Ne7 15. Nh5 Nhg6 16. Bxg7 Kf7 17. Bd4 Rc8 18. d3 Nh4 19. Rxg8 Rxg8 20. Bf6 Ng2+ 21. Kd2 Bd6 22. Bd4 Kg6 23. Nfg3 Bb4+ 24. Kc2 d5 25. Bb3 f4

26. Nf6 Rc8 27. Kb2 fxg3 28. hxg3 Bd6 29. e4 Rd8 30. e5 Bb4 31. Bc3 Bc5

32. d4 Bxb6 33. Rg1 Rb8 34. Bc2+ Kg7 35. Kc1 Rc8 36. Kd2 Nf5 37. Nh5+ Kh8 38. Bxf5 exf5 39. Rxg2 Ra8 40. Rg1 Rxa2+ 41. Ke3 Bd8 42. Bb4 Be8 43. Nf4 Bg5 44. Rc1 Bxf4+ 45. Kxf4 Rxf2+ 46. Ke3 Rb2

47. Rc8 Kg7 48. Rxe8 Rb3+ 49. Kf4 Rxb4 50. Kxf5 Rxd4 51. Re7+ Kf8 52. Rxh7 Rd3 53. g4 d4 54. Rd7 Rf3+ 55. Ke4 Re3+ 56. Kf4 Rd3 57. g5 Rd1 58. Ke4 Re1+ 59. Kf5 Rd1

60. Ke6 Ke8 61. g6 Kf8 62. Rf7+ Kg8 63. Kd7 Re1 64. e6 d3 65. Rf2 Kg7 66. e7 Kh6 67. e8=Q Rg1 68. Qh8+ Kg5 69. g7 Kg4 70. g8=Q# 1 : 0.

The Binding

Leela Chess Zero – Stockfish

Top Chess Engine Championship Season 21 — FRC4 Final; match game 24; tcec-chess.com, January 5, 2022

rqnbkrbn/pppppppp/8/8/8/8/PPPPPPPP/RQNBKRBN w FAfa - 0 1

Position #605

1. Ng3 c5 2. Nh5 Qe5 3. g4 e6 4. Nd3 Qg5 5. e4 c4 6. f4 Qg6 7. f5 exf5 8. exf5 Bh4+ 9. Bf2 Qg5

10. 0-0 cxd3 11. Bxh4 Qxh4 12. f6 g6 13. Ng7+ Kd8 14. cxd3 Nd6 15. b4 Qg5 16. Qb2 Rc8 17. a4 Ne8

18. h4 Qd5 19. g5 Nd6 20. Bf3 Qxd3 21. Ra3 Nc4 22. Rxd3 Nxb2 23. Rd5 Rc4 24. a5 Kc8 25. b5 Rd8 26. Re1 Rf4 27. Kg2 h6 28. Kg3 Ra4 29. Ne8 Nc4 30. Re4 hxg5 31. hxg5 b6

32. Rxc4+ Rxc4 33. Nd6+ Kb8 34. Nxc4 bxa5 35. Kf4 a4 36. Ke5 Rc8 37. Rxd7 Rc7

38. Kd6 Rxc4 39. Rb7+ Kc8 40. Rxa7 Rd4+ 41. Bd5 Rxd5+ 42. Kxd5 a3 43. Kc6 Kb8 44. Rxa3 Bh7 45. b6 Bg8 46. b7 Bh7 47. Ra8# 1–0.

Beckett’s Theatre

Stockfish – Leela Chess Zero

Top Chess Engine Championship Season 21 — FRC4 Final; match game 38; tcec-chess.com, January 6, 2022

nrkbrnbq/pppppppp/8/8/8/8/PPPPPPPP/NRKBRNBQ w EBeb - 0 1

Position #902

1. e4 c5 2. d4 cxd4 3. f4 d6 4. Qxd4 e5 5. Qd3 exf4 6. Bxf4 Ng6 7. Bg3 Nf6 8. Nf3 Nh5 9. Bf2 Nf6 10. Ng3 Qa5 11. Bd4 Ne5 12. Qc3 Qxc3 13. Bxc3 Nfd7 14. Nf5 Nc5 15. Bb5 Nc6

16. 0-0-0 Nxe4 17. Ng3 f5 18. Ng5 a6 19. Bc4 Ne5 20. N3xe4 Nxc4 21. Nd2 Ne3 22. Nxh7 f4 23. Nc4 Be7 24. Nxd6 Bxd6 25. Rxd6 Bf5 26. Ng5 0-0-0 27. Rd2 Bg6 28. Rxd8+ Rxd8 29. g4 Nxg4 30. Ne6 Re8 31. Nxf4 Rxe1+ 32. Bxe1 Bf5 33. Bg3 Nf6

34. Ne2 Ne4 35. Nd4 Bh3 36. Be5 g6 37. a4 Kd8 38. a5 Ke7 39. c4 Bf1 40. b3 g5 41. Kd1 Kd7 42. Ke1 Bd3 43. Ne2 Bc2 44. Nc1 Ke6 45. Bb8 Kf5 46. Ne2 Kf6 47. Nd4 Bd3 48. Kd1 Bf1 49. Ke1 Bd3 50. Kd1 Bf1 51. Ba7 Ke5 52. Ne2 Kf6 53. Nc1 Nd6 54. Ke1 Bg2 55. Kf2 Be4 56. Ke3 Bg2 57. Kd4 Nf5+ 58. Kc3 Ke7 59. Nd3 Ke6 60. Bc5 Kd7 61. Bd4 Ke7 62. Nc5 Kf7 63. Be5 Bf3 64. b4 Bc6 65. Kc2 Ne3+ 66. Kd3 Nf5 67. Ne4 Kg6 68. Bg3 Kh5 69. Bc7 Kg6 70. Be5 Nh6 71. Bg3 Nf5 72. Be1 g4 73. Bg3 Kf7 74. Nf2 Bf3

75. b5 Ke7 76. Bf4 Kd7 77. Ne4 Kc8 78. Nc5 axb5 79. cxb5 Kd8 80. Be5 Bg2 81. Kc3 Bh1 82. Na4 Bf3 83. Nb6 Be2 84. Kb4 Ke7 85. Kc5 Ke6 86. Bg3 Ne3 87. Bf4 Nf5 88. Nc4 Ne7 89. Nd6 Bf3 90. Bg3 Kd7 91. Nc4 Be2 92. Ne5+ Kc8 93. Bf4 Nf5 94. Nc4 Kd7

95. a6 bxa6 96. bxa6 Ke6 97. a7 Bf3 98. Nb6 Ne7 99. Bg3 Bh1 100. a8=Q Bxa8 101. Nxa8 Kf5 102. Nb6 Ng6 103. Nd5 Kg5 104. Bd6 Nh8 105. Ne3 Ng6 106. Kd4 Kh5 107. Ke4 Kg5 108. Nd5 Nh8 109. Nf4 Kh6 110. Kf5 Nf7 111. Be7 Kh7 112. Kxg4 1 : 0.

The Golden Fish

Stockfish – Stoofvlees

Top Chess Engine Championship Season 21 — Division P; tcec-chess.com, June 22, 2021

Sicilian Defence B81

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e6 6. g4 Be7 7. g5 Nfd7 8. h4 Nc6 9. Be3 0-0 10. f4 Qb6 11. a3!? Indirectly defending the b-Pawn. Instead, the human theory gave only 11. Rb1 d5 12. e5⩲ Kruppa – Golod, 57th Ukrainian Chess Championship, Kharkov 1988. 11. ... d5. Of course not 11. ... Qxb2?? because of 12. Na4 trapping the Queen. On the other hand, it would be disconcerting, to say the least, if the text move were the cause of Black’s calamities. And yet... 12. exd5 Nxd4 13. Bxd4 Bc5 14. Bxc5 Nxc5 15. Qd4 exd5. Again here, if 15. ... Qxb2? then 16. Qxc5! Qxa1+ 17. Kd2 with overwhelming compensation for the Exchange. Maybe 15. ... e5 could be considered, even if also in this case White would have little to worry about: 16. Qb4! exf4 17. 0-0-0 with powerful advantage. 16. 0-0-0 Bg4. If Stoofvlees were a human being rather than a machine, it could be inferred that “he” had relied a lot upon this move. 17. Nxd5 Qa5

18. h5! This gain of tempo proves devastating. 18. ... Ne6. The Rook is taboo, since 18. ... Bxd1? 19. h6! Ne6 20. Ne7+ Kh8 21. hxg7+ Nxg7 22. Qxd1 gives White a mating attack. 19. Qe5 Qc5 (19. ... Bxd1?? 20. Ne7++−) 20. b4 Qf2 21. Bd3 Rfd8. The Rook is untouchable for the same reason as mentioned above: 21. ... Bxd1? 22. Ne7+ Kh8 23. h6! with mating attack. 22. h6. Threat: Bd3xh7+. 22. ... g6. If 22. ... Rxd5!? (just hoping for 23. Qxd5?? Qxf4+ 24. Kb2 Bf3∞) then 23. Bxh7+! winning by force. 23. Ne7+ Kf8

24. Nxg6+! hxg6. If 24. ... fxg6 then 25. Qf6+ Kg8 (or 5. ... Ke8 26. Bb5+ followed by mate) 26. Bc4! with mate in a few moves. 25. h7 Ke7 26. Qf6+ Kd7 27. Qxf7+ Kc6 28. Be4+ Kb5 29. Qxb7+ Qb6

30. h8=Q! Bxd1. Or 30. ... Rxh8 31. Qd7+! followed by mate in two. 31. Qe5+ Nc5 32. Bc6+ Kc4 33. Qf7+ Ne6 34. Qfxe6+ Rd5 35. Q6xd5# 1 : 0.