Latest SF Dev Build Loses a Drawn Match

#1

I was playing with the latest SF Build (20191210-0707) and the match was a draw until SF started playing moves which were clearly not acceptable.

It turned the match from a Draw to a Loss for SF.

My settings were 20× CPU Core, latest SF 20191210-0707, 1 sec think time, 6-man TB and Contempt 24. I was playing Black. This was the most shocking part as SF was playing White at full strength.

Here’s the PGN:-

  1. d4 d5 2. c4 e6 3. Nf3 Nf6 4. Nc3 c6 5. e3 Nbd7 6. Qc2 Bd6
  2. Bd3 O-O 8. O-O dxc4 9. Bxc4 b5 10. Be2 Bb7 11. e4 e5
  3. dxe5 Nxe5 13. Rd1 Qc7 14. Nd4 Rad8 15. Nf5 Bc5 16. Bf4 g6
  4. Rxd8 Rxd8 18. Bg5 Ned7 19. Nh6+ Kg7 20. Rd1 Ne5 21. Rf1 b4
  5. Na4 Bd4 23. Nc5 Re8 24. Nb3 Bb6 25. Kh1 c5 26. Nd2 c4
  6. f4 Nd3 28. Bxf6+ Kxf6 29. Nxc4 Nf2+ 30. Rxf2 Bxf2 31. Ng4+ Kg7
  7. Nxf2 Qxf4 33. Kg1 Bxe4 34. Nxe4 Qxe4 35. Qxe4 Rxe4 36. Kf2 f5
  8. Ne3 Rd4 38. Ke1 Rd6 39. Nc2 Rb6 40. Ne3 Rd6 41. h3 h5
  9. Nc2 Rb6 43. Nd4 Rd6 44. Nc2 Rb6 45. Bc4 Kf6 46. h4 Rd6
  10. Nxb4 Rd4 48. b3 Rxh4 49. a4 g5 50. Nc6 Rh1+ 51. Kf2 h4
  11. Nxa7 g4 53. Nc6 Ra1 54. Nb4 f4 55. Bd5 Kg5 56. Be6 Rd1
  12. Ke2 Rd4 58. a5 Re4+ 59. Kf1 Rxe6 60. Nd3 Re3 61. Nf2 Rxb3
  13. Ne4+ Kg6 63. Nd2 Ra3 64. Nc4 Ra2 65. Ne5+ Kf5 66. Nd3 g3
  14. Nb4 Rf2+ 68. Ke1 Rxg2 69. Kd1 h3 70. Nc2 h2 71. Kc1 h1=Q+
  15. Kb2 Qd1 73. Ka3 Rxc2 74. a6 Qb1 75. a7 Ra2#

Till move 40-45, the game was expected to end in a draw. To my surprise, after 45-50 it was sure for a loss.

Thanks for reading such a long post. But please help if possible and explain the analysis that why did SF as White lose with full strength in such a Draw Match.

#2

Greetings!

Sorry for the delay in response. I think the culprit is the 1 second think time.

The forums interpreted your PGN as a list, so I’m pasting the PGN I used to analyze here:

1. d4 d5 2. c4 e6 3. Nf3 Nf6 4. Nc3 c6 5. e3 Nbd7 6. Qc2 Bd6
7. Bd3 O-O 8. O-O dxc4 9. Bxc4 b5 10. Be2 Bb7 11. e4 e5
12. dxe5 Nxe5 13. Rd1 Qc7 14. Nd4 Rad8 15. Nf5 Bc5 16. Bf4 g6
17. Rxd8 Rxd8 18. Bg5 Ned7 19. Nh6+ Kg7 20. Rd1 Ne5 21. Rf1 b4
22. Na4 Bd4 23. Nc5 Re8 24. Nb3 Bb6 25. Kh1 c5 26. Nd2 c4
27. f4 Nd3 28. Bxf6+ Kxf6 29. Nxc4 Nf2+ 30. Rxf2 Bxf2 31. Ng4+ Kg7
32. Nxf2 Qxf4 33. Kg1 Bxe4 34. Nxe4 Qxe4 35. Qxe4 Rxe4 36. Kf2 f5
37. Ne3 Rd4 38. Ke1 Rd6 39. Nc2 Rb6 40. Ne3 Rd6 41. h3 h5
42. Nc2 Rb6 43. Nd4 Rd6 44. Nc2 Rb6 45. Bc4 Kf6 46. h4 Rd6
47. Nxb4 Rd4 48. b3 Rxh4 49. a4 g5 50. Nc6 Rh1+ 51. Kf2 h4
52. Nxa7 g4 53. Nc6 Ra1 54. Nb4 f4 55. Bd5 Kg5 56. Be6 Rd1
57. Ke2 Rd4 58. a5 Re4+ 59. Kf1 Rxe6 60. Nd3 Re3 61. Nf2 Rxb3
62. Ne4+ Kg6 63. Nd2 Ra3 64. Nc4 Ra2 65. Ne5+ Kf5 66. Nd3 g3
67. Nb4 Rf2+ 68. Ke1 Rxg2 69. Kd1 h3 70. Nc2 h2 71. Kc1 h1=Q+
72. Kb2 Qd1 73. Ka3 Rxc2 74. a6 Qb1 75. a7 Ra2#

Using that PGN, I hacked together a quick script to analyze each position with same dev build that you were using, but using 15 seconds per move instead of 1. Here’s a CSV containing the results:

ply,fen,player,played_move,engine_move,score
1,rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1,white,d4,d2d4,cp 52
2,rnbqkbnr/pppppppp/8/8/3P4/8/PPP1PPPP/RNBQKBNR b KQkq d3 0 1,black,d5,g8f6,cp 0
3,rnbqkbnr/ppp1pppp/8/3p4/3P4/8/PPP1PPPP/RNBQKBNR w KQkq d6 0 2,white,c4,c2c4,cp 51
4,rnbqkbnr/ppp1pppp/8/3p4/2PP4/8/PP2PPPP/RNBQKBNR b KQkq c3 0 2,black,e6,e7e6,cp -11
5,rnbqkbnr/ppp2ppp/4p3/3p4/2PP4/8/PP2PPPP/RNBQKBNR w KQkq - 0 3,white,Nf3,b1c3,cp 66
6,rnbqkbnr/ppp2ppp/4p3/3p4/2PP4/5N2/PP2PPPP/RNBQKB1R b KQkq - 1 3,black,Nf6,g8f6,cp 10
7,rnbqkb1r/ppp2ppp/4pn2/3p4/2PP4/5N2/PP2PPPP/RNBQKB1R w KQkq - 2 4,white,Nc3,b1c3,cp 55
8,rnbqkb1r/ppp2ppp/4pn2/3p4/2PP4/2N2N2/PP2PPPP/R1BQKB1R b KQkq - 3 4,black,c6,c7c6,cp 20
9,rnbqkb1r/pp3ppp/2p1pn2/3p4/2PP4/2N2N2/PP2PPPP/R1BQKB1R w KQkq - 0 5,white,e3,e2e3,cp 44
10,rnbqkb1r/pp3ppp/2p1pn2/3p4/2PP4/2N1PN2/PP3PPP/R1BQKB1R b KQkq - 0 5,black,Nbd7,b8d7,cp 0
11,r1bqkb1r/pp1n1ppp/2p1pn2/3p4/2PP4/2N1PN2/PP3PPP/R1BQKB1R w KQkq - 1 6,white,Qc2,d1c2,cp 53
12,r1bqkb1r/pp1n1ppp/2p1pn2/3p4/2PP4/2N1PN2/PPQ2PPP/R1B1KB1R b KQkq - 2 6,black,Bd6,f8d6,cp 0
13,r1bqk2r/pp1n1ppp/2pbpn2/3p4/2PP4/2N1PN2/PPQ2PPP/R1B1KB1R w KQkq - 3 7,white,Bd3,f1d3,cp 54
14,r1bqk2r/pp1n1ppp/2pbpn2/3p4/2PP4/2NBPN2/PPQ2PPP/R1B1K2R b KQkq - 4 7,black,O-O,d5c4,cp -1
15,r1bq1rk1/pp1n1ppp/2pbpn2/3p4/2PP4/2NBPN2/PPQ2PPP/R1B1K2R w KQ - 5 8,white,O-O,e1g1,cp 72
16,r1bq1rk1/pp1n1ppp/2pbpn2/3p4/2PP4/2NBPN2/PPQ2PPP/R1B2RK1 b - - 6 8,black,dxc4,d5c4,cp 0
17,r1bq1rk1/pp1n1ppp/2pbpn2/8/2pP4/2NBPN2/PPQ2PPP/R1B2RK1 w - - 0 9,white,Bxc4,d3c4,cp 56
18,r1bq1rk1/pp1n1ppp/2pbpn2/8/2BP4/2N1PN2/PPQ2PPP/R1B2RK1 b - - 0 9,black,b5,b7b5,cp -5
19,r1bq1rk1/p2n1ppp/2pbpn2/1p6/2BP4/2N1PN2/PPQ2PPP/R1B2RK1 w - b6 0 10,white,Be2,c4d3,cp 37
20,r1bq1rk1/p2n1ppp/2pbpn2/1p6/3P4/2N1PN2/PPQ1BPPP/R1B2RK1 b - - 1 10,black,Bb7,a7a6,cp 0
21,r2q1rk1/pb1n1ppp/2pbpn2/1p6/3P4/2N1PN2/PPQ1BPPP/R1B2RK1 w - - 2 11,white,e4,e3e4,cp 49
22,r2q1rk1/pb1n1ppp/2pbpn2/1p6/3PP3/2N2N2/PPQ1BPPP/R1B2RK1 b - - 0 11,black,e5,e6e5,cp 0
23,r2q1rk1/pb1n1ppp/2pb1n2/1p2p3/3PP3/2N2N2/PPQ1BPPP/R1B2RK1 w - - 0 12,white,dxe5,f1d1,cp 35
24,r2q1rk1/pb1n1ppp/2pb1n2/1p2P3/4P3/2N2N2/PPQ1BPPP/R1B2RK1 b - - 0 12,black,Nxe5,d7e5,cp -9
25,r2q1rk1/pb3ppp/2pb1n2/1p2n3/4P3/2N2N2/PPQ1BPPP/R1B2RK1 w - - 0 13,white,Rd1,f3h4,cp 49
26,r2q1rk1/pb3ppp/2pb1n2/1p2n3/4P3/2N2N2/PPQ1BPPP/R1BR2K1 b - - 1 13,black,Qc7,d8c7,cp 6
27,r4rk1/pbq2ppp/2pb1n2/1p2n3/4P3/2N2N2/PPQ1BPPP/R1BR2K1 w - - 2 14,white,Nd4,f3d4,cp 13
28,r4rk1/pbq2ppp/2pb1n2/1p2n3/3NP3/2N5/PPQ1BPPP/R1BR2K1 b - - 3 14,black,Rad8,d6c5,cp 0
29,3r1rk1/pbq2ppp/2pb1n2/1p2n3/3NP3/2N5/PPQ1BPPP/R1BR2K1 w - - 4 15,white,Nf5,d4f5,cp 35
30,3r1rk1/pbq2ppp/2pb1n2/1p2nN2/4P3/2N5/PPQ1BPPP/R1BR2K1 b - - 5 15,black,Bc5,d6c5,cp -10
31,3r1rk1/pbq2ppp/2p2n2/1pb1nN2/4P3/2N5/PPQ1BPPP/R1BR2K1 w - - 6 16,white,Bf4,c1f4,cp 34
32,3r1rk1/pbq2ppp/2p2n2/1pb1nN2/4PB2/2N5/PPQ1BPPP/R2R2K1 b - - 7 16,black,g6,e5f3,cp 0
33,3r1rk1/pbq2p1p/2p2np1/1pb1nN2/4PB2/2N5/PPQ1BPPP/R2R2K1 w - - 0 17,white,Rxd8,d1d8,cp 77
34,3R1rk1/pbq2p1p/2p2np1/1pb1nN2/4PB2/2N5/PPQ1BPPP/R5K1 b - - 0 17,black,Rxd8,f8d8,cp -7
35,3r2k1/pbq2p1p/2p2np1/1pb1nN2/4PB2/2N5/PPQ1BPPP/R5K1 w - - 0 18,white,Bg5,f4g5,cp 39
36,3r2k1/pbq2p1p/2p2np1/1pb1nNB1/4P3/2N5/PPQ1BPPP/R5K1 b - - 1 18,black,Ned7,e5d7,cp 0
37,3r2k1/pbqn1p1p/2p2np1/1pb2NB1/4P3/2N5/PPQ1BPPP/R5K1 w - - 2 19,white,Nh6+,f5h6,cp 39
38,3r2k1/pbqn1p1p/2p2npN/1pb3B1/4P3/2N5/PPQ1BPPP/R5K1 b - - 3 19,black,Kg7,g8g7,cp 0
39,3r4/pbqn1pkp/2p2npN/1pb3B1/4P3/2N5/PPQ1BPPP/R5K1 w - - 4 20,white,Rd1,a1d1,cp 27
40,3r4/pbqn1pkp/2p2npN/1pb3B1/4P3/2N5/PPQ1BPPP/3R2K1 b - - 5 20,black,Ne5,b5b4,cp -10
41,3r4/pbq2pkp/2p2npN/1pb1n1B1/4P3/2N5/PPQ1BPPP/3R2K1 w - - 6 21,white,Rf1,d1f1,cp 53
42,3r4/pbq2pkp/2p2npN/1pb1n1B1/4P3/2N5/PPQ1BPPP/5RK1 b - - 7 21,black,b4,b5b4,cp -13
43,3r4/pbq2pkp/2p2npN/2b1n1B1/1p2P3/2N5/PPQ1BPPP/5RK1 w - - 0 22,white,Na4,c3a4,cp 56
44,3r4/pbq2pkp/2p2npN/2b1n1B1/Np2P3/8/PPQ1BPPP/5RK1 b - - 1 22,black,Bd4,c5d4,cp -23
45,3r4/pbq2pkp/2p2npN/4n1B1/Np1bP3/8/PPQ1BPPP/5RK1 w - - 2 23,white,Nc5,a4c5,cp 29
46,3r4/pbq2pkp/2p2npN/2N1n1B1/1p1bP3/8/PPQ1BPPP/5RK1 b - - 3 23,black,Re8,d8e8,cp 0
47,4r3/pbq2pkp/2p2npN/2N1n1B1/1p1bP3/8/PPQ1BPPP/5RK1 w - - 4 24,white,Nb3,c5b3,cp 20
48,4r3/pbq2pkp/2p2npN/4n1B1/1p1bP3/1N6/PPQ1BPPP/5RK1 b - - 5 24,black,Bb6,d4b6,cp -10
49,4r3/pbq2pkp/1bp2npN/4n1B1/1p2P3/1N6/PPQ1BPPP/5RK1 w - - 6 25,white,Kh1,g1h1,cp 24
50,4r3/pbq2pkp/1bp2npN/4n1B1/1p2P3/1N6/PPQ1BPPP/5R1K b - - 7 25,black,c5,c6c5,cp 0
51,4r3/pbq2pkp/1b3npN/2p1n1B1/1p2P3/1N6/PPQ1BPPP/5R1K w - - 0 26,white,Nd2,b3d2,cp 21
52,4r3/pbq2pkp/1b3npN/2p1n1B1/1p2P3/8/PPQNBPPP/5R1K b - - 1 26,black,c4,c5c4,cp 0
53,4r3/pbq2pkp/1b3npN/4n1B1/1pp1P3/8/PPQNBPPP/5R1K w - - 0 27,white,f4,f2f4,cp 12
54,4r3/pbq2pkp/1b3npN/4n1B1/1pp1PP2/8/PPQNB1PP/5R1K b - f3 0 27,black,Nd3,e5d3,cp 0
55,4r3/pbq2pkp/1b3npN/6B1/1pp1PP2/3n4/PPQNB1PP/5R1K w - - 1 28,white,Bxf6+,g5f6,cp 32
56,4r3/pbq2pkp/1b3BpN/8/1pp1PP2/3n4/PPQNB1PP/5R1K b - - 0 28,black,Kxf6,g7f6,cp 0
57,4r3/pbq2p1p/1b3kpN/8/1pp1PP2/3n4/PPQNB1PP/5R1K w - - 0 29,white,Nxc4,d2c4,cp 17
58,4r3/pbq2p1p/1b3kpN/8/1pN1PP2/3n4/PPQ1B1PP/5R1K b - - 0 29,black,Nf2+,d3f2,cp 0
59,4r3/pbq2p1p/1b3kpN/8/1pN1PP2/8/PPQ1BnPP/5R1K w - - 1 30,white,Rxf2,f1f2,cp 15
60,4r3/pbq2p1p/1b3kpN/8/1pN1PP2/8/PPQ1BRPP/7K b - - 0 30,black,Bxf2,b6f2,cp 0
61,4r3/pbq2p1p/5kpN/8/1pN1PP2/8/PPQ1BbPP/7K w - - 0 31,white,Ng4+,h6g4,cp 13
62,4r3/pbq2p1p/5kp1/8/1pN1PPN1/8/PPQ1BbPP/7K b - - 1 31,black,Kg7,f6g7,cp 0
63,4r3/pbq2pkp/6p1/8/1pN1PPN1/8/PPQ1BbPP/7K w - - 2 32,white,Nxf2,g4f2,cp 23
64,4r3/pbq2pkp/6p1/8/1pN1PP2/8/PPQ1BNPP/7K b - - 0 32,black,Qxf4,c7f4,cp 0
65,4r3/pb3pkp/6p1/8/1pN1Pq2/8/PPQ1BNPP/7K w - - 0 33,white,Kg1,h1g1,cp 10
66,4r3/pb3pkp/6p1/8/1pN1Pq2/8/PPQ1BNPP/6K1 b - - 1 33,black,Bxe4,b7e4,cp 0
67,4r3/p4pkp/6p1/8/1pN1bq2/8/PPQ1BNPP/6K1 w - - 0 34,white,Nxe4,f2e4,cp 28
68,4r3/p4pkp/6p1/8/1pN1Nq2/8/PPQ1B1PP/6K1 b - - 0 34,black,Qxe4,f4e4,cp 0
69,4r3/p4pkp/6p1/8/1pN1q3/8/PPQ1B1PP/6K1 w - - 0 35,white,Qxe4,c2e4,cp 13
70,4r3/p4pkp/6p1/8/1pN1Q3/8/PP2B1PP/6K1 b - - 0 35,black,Rxe4,e8e4,cp 0
71,8/p4pkp/6p1/8/1pN1r3/8/PP2B1PP/6K1 w - - 0 36,white,Kf2,g1f2,cp 0
72,8/p4pkp/6p1/8/1pN1r3/8/PP2BKPP/8 b - - 1 36,black,f5,f7f5,cp 0
73,8/p5kp/6p1/5p2/1pN1r3/8/PP2BKPP/8 w - f6 0 37,white,Ne3,c4e3,cp 17
74,8/p5kp/6p1/5p2/1p2r3/4N3/PP2BKPP/8 b - - 1 37,black,Rd4,f5f4,cp 0
75,8/p5kp/6p1/5p2/1p1r4/4N3/PP2BKPP/8 w - - 2 38,white,Ke1,f2e1,cp 0
76,8/p5kp/6p1/5p2/1p1r4/4N3/PP2B1PP/4K3 b - - 3 38,black,Rd6,g7f6,cp 0
77,8/p5kp/3r2p1/5p2/1p6/4N3/PP2B1PP/4K3 w - - 4 39,white,Nc2,e3c2,cp 10
78,8/p5kp/3r2p1/5p2/1p6/8/PPN1B1PP/4K3 b - - 5 39,black,Rb6,d6b6,cp 0
79,8/p5kp/1r4p1/5p2/1p6/8/PPN1B1PP/4K3 w - - 6 40,white,Ne3,c2e3,cp 16
80,8/p5kp/1r4p1/5p2/1p6/4N3/PP2B1PP/4K3 b - - 7 40,black,Rd6,b6d6,cp 0
81,8/p5kp/3r2p1/5p2/1p6/4N3/PP2B1PP/4K3 w - - 8 41,white,h3,e3c2,cp 0
82,8/p5kp/3r2p1/5p2/1p6/4N2P/PP2B1P1/4K3 b - - 0 41,black,h5,g7f6,cp 0
83,8/p5k1/3r2p1/5p1p/1p6/4N2P/PP2B1P1/4K3 w - h6 0 42,white,Nc2,e3c2,cp 0
84,8/p5k1/3r2p1/5p1p/1p6/7P/PPN1B1P1/4K3 b - - 1 42,black,Rb6,d6b6,cp 0
85,8/p5k1/1r4p1/5p1p/1p6/7P/PPN1B1P1/4K3 w - - 2 43,white,Nd4,c2d4,cp 0
86,8/p5k1/1r4p1/5p1p/1p1N4/7P/PP2B1P1/4K3 b - - 3 43,black,Rd6,g7f6,cp 0
87,8/p5k1/3r2p1/5p1p/1p1N4/7P/PP2B1P1/4K3 w - - 4 44,white,Nc2,d4c2,cp 0
88,8/p5k1/3r2p1/5p1p/1p6/7P/PPN1B1P1/4K3 b - - 5 44,black,Rb6,d6b6,cp 0
89,8/p5k1/1r4p1/5p1p/1p6/7P/PPN1B1P1/4K3 w - - 6 45,white,Bc4,e2c4,cp 0
90,8/p5k1/1r4p1/5p1p/1pB5/7P/PPN3P1/4K3 b - - 7 45,black,Kf6,g7f6,cp 0
91,8/p7/1r3kp1/5p1p/1pB5/7P/PPN3P1/4K3 w - - 8 46,white,h4,h3h4,cp 0
92,8/p7/1r3kp1/5p1p/1pB4P/8/PPN3P1/4K3 b - - 0 46,black,Rd6,g6g5,cp 0
93,8/p7/3r1kp1/5p1p/1pB4P/8/PPN3P1/4K3 w - - 1 47,white,Nxb4,c4e2,cp 0
94,8/p7/3r1kp1/5p1p/1NB4P/8/PP4P1/4K3 b - - 0 47,black,Rd4,d6d4,cp 138
95,8/p7/5kp1/5p1p/1NBr3P/8/PP4P1/4K3 w - - 1 48,white,b3,b2b3,cp -123
96,8/p7/5kp1/5p1p/1NBr3P/1P6/P5P1/4K3 b - - 0 48,black,Rxh4,d4h4,cp 143
97,8/p7/5kp1/5p1p/1NB4r/1P6/P5P1/4K3 w - - 0 49,white,a4,a2a4,cp -109
98,8/p7/5kp1/5p1p/PNB4r/1P6/6P1/4K3 b - a3 0 49,black,g5,g6g5,cp 146
99,8/p7/5k2/5ppp/PNB4r/1P6/6P1/4K3 w - - 0 50,white,Nc6,e1f2,cp -104
100,8/p7/2N2k2/5ppp/P1B4r/1P6/6P1/4K3 b - - 1 50,black,Rh1+,h4h1,cp 153
101,8/p7/2N2k2/5ppp/P1B5/1P6/6P1/4K2r w - - 2 51,white,Kf2,e1f2,cp -120
102,8/p7/2N2k2/5ppp/P1B5/1P6/5KP1/7r b - - 3 51,black,h4,h5h4,cp 164
103,8/p7/2N2k2/5pp1/P1B4p/1P6/5KP1/7r w - - 0 52,white,Nxa7,c6a7,cp -109
104,8/N7/5k2/5pp1/P1B4p/1P6/5KP1/7r b - - 0 52,black,g4,g5g4,cp 135
105,8/N7/5k2/5p2/P1B3pp/1P6/5KP1/7r w - - 0 53,white,Nc6,a7c6,cp -119
106,8/8/2N2k2/5p2/P1B3pp/1P6/5KP1/7r b - - 1 53,black,Ra1,h1a1,cp 90
107,8/8/2N2k2/5p2/P1B3pp/1P6/5KP1/r7 w - - 2 54,white,Nb4,c4e2,cp -124
108,8/8/5k2/5p2/PNB3pp/1P6/5KP1/r7 b - - 3 54,black,f4,f5f4,cp 177
109,8/8/5k2/8/PNB2ppp/1P6/5KP1/r7 w - - 0 55,white,Bd5,c4d5,cp -32
110,8/8/5k2/3B4/PN3ppp/1P6/5KP1/r7 b - - 1 55,black,Kg5,f6g5,cp 22
111,8/8/8/3B2k1/PN3ppp/1P6/5KP1/r7 w - - 2 56,white,Be6,d5e4,cp 0
112,8/8/4B3/6k1/PN3ppp/1P6/5KP1/r7 b - - 3 56,black,Rd1,g4g3,cp 719
113,8/8/4B3/6k1/PN3ppp/1P6/5KP1/3r4 w - - 4 57,white,Ke2,f2e2,cp -1630
114,8/8/4B3/6k1/PN3ppp/1P6/4K1P1/3r4 b - - 5 57,black,Rd4,d1d4,cp 1839
115,8/8/4B3/6k1/PN1r1ppp/1P6/4K1P1/8 w - - 6 58,white,a5,a4a5,cp -1920
116,8/8/4B3/P5k1/1N1r1ppp/1P6/4K1P1/8 b - - 0 58,black,Re4+,d4e4,cp 14792
117,8/8/4B3/P5k1/1N2rppp/1P6/4K1P1/8 w - - 1 59,white,Kf1,e2f1,cp -2387
118,8/8/4B3/P5k1/1N2rppp/1P6/6P1/5K2 b - - 2 59,black,Rxe6,e4e6,cp 3037
119,8/8/4r3/P5k1/1N3ppp/1P6/6P1/5K2 w - - 0 60,white,Nd3,b4d3,cp -2331
120,8/8/4r3/P5k1/5ppp/1P1N4/6P1/5K2 b - - 1 60,black,Re3,e6d6,cp 2966
121,8/8/8/P5k1/5ppp/1P1Nr3/6P1/5K2 w - - 2 61,white,Nf2,d3f2,cp -14902
122,8/8/8/P5k1/5ppp/1P2r3/5NP1/5K2 b - - 3 61,black,Rxb3,f4f3,cp 14903
123,8/8/8/P5k1/5ppp/1r6/5NP1/5K2 w - - 0 62,white,Ne4+,f1e1,cp -14903
124,8/8/8/P5k1/4Nppp/1r6/6P1/5K2 b - - 1 62,black,Kg6,g5f5,mate 15
125,8/8/6k1/P7/4Nppp/1r6/6P1/5K2 w - - 2 63,white,Nd2,a5a6,cp -14902
126,8/8/6k1/P7/5ppp/1r6/3N2P1/5K2 b - - 3 63,black,Ra3,b3b2,mate 14
127,8/8/6k1/P7/5ppp/r7/3N2P1/5K2 w - - 4 64,white,Nc4,d2c4,mate -16
128,8/8/6k1/P7/2N2ppp/r7/6P1/5K2 b - - 5 64,black,Ra2,a3a1,mate 17
129,8/8/6k1/P7/2N2ppp/8/r5P1/5K2 w - - 6 65,white,Ne5+,a5a6,mate -14
130,8/8/6k1/P3N3/5ppp/8/r5P1/5K2 b - - 7 65,black,Kf5,g6f5,mate 11
131,8/8/8/P3Nk2/5ppp/8/r5P1/5K2 w - - 8 66,white,Nd3,e5d3,mate -10
132,8/8/8/P4k2/5ppp/3N4/r5P1/5K2 b - - 9 66,black,g3,h4h3,mate 11
133,8/8/8/P4k2/5p1p/3N2p1/r5P1/5K2 w - - 0 67,white,Nb4,d3c1,mate -9
134,8/8/8/P4k2/1N3p1p/6p1/r5P1/5K2 b - - 1 67,black,Rf2+,a2f2,mate 9
135,8/8/8/P4k2/1N3p1p/6p1/5rP1/5K2 w - - 2 68,white,Ke1,f1e1,mate -8
136,8/8/8/P4k2/1N3p1p/6p1/5rP1/4K3 b - - 3 68,black,Rxg2,f2g2,mate 8
137,8/8/8/P4k2/1N3p1p/6p1/6r1/4K3 w - - 0 69,white,Kd1,b4d5,mate -7
138,8/8/8/P4k2/1N3p1p/6p1/6r1/3K4 b - - 1 69,black,h3,h4h3,mate 7
139,8/8/8/P4k2/1N3p2/6pp/6r1/3K4 w - - 0 70,white,Nc2,b4c2,mate -6
140,8/8/8/P4k2/5p2/6pp/2N3r1/3K4 b - - 1 70,black,h2,h3h2,mate 6
141,8/8/8/P4k2/5p2/6p1/2N3rp/3K4 w - - 0 71,white,Kc1,d1c1,mate -5
142,8/8/8/P4k2/5p2/6p1/2N3rp/2K5 b - - 1 71,black,h1=Q+,h2h1q,mate 5
143,8/8/8/P4k2/5p2/6p1/2N3r1/2K4q w - - 0 72,white,Kb2,c1b2,mate -4
144,8/8/8/P4k2/5p2/6p1/1KN3r1/7q b - - 1 72,black,Qd1,h1d1,mate 4
145,8/8/8/P4k2/5p2/6p1/1KN3r1/3q4 w - - 2 73,white,Ka3,b2a3,mate -3
146,8/8/8/P4k2/5p2/K5p1/2N3r1/3q4 b - - 3 73,black,Rxc2,g2c2,mate 3
147,8/8/8/P4k2/5p2/K5p1/2r5/3q4 w - - 0 74,white,a6,a5a6,mate -2
148,8/8/P7/5k2/5p2/K5p1/2r5/3q4 b - - 0 74,black,Qb1,d1b1,mate 2
149,8/8/P7/5k2/5p2/K5p1/2r5/1q6 w - - 1 75,white,a7,a6a7,mate -1
150,8/P7/8/5k2/5p2/K5p1/2r5/1q6 b - - 0 75,black,Ra2#,c2a2,mate 1

The output CSV above is a bit messy in certain aspects:

  1. the played_move uses SAN notation whereas engine_move does not,
  2. score is verbatim from the engine, so it’s in centipawn units, and
    positive values always mean the active color has the advantage.

In any case, it looks like the draw started to fall apart at ply 111 with Be6.

Next I tried this position with the same settings (1s per move) 50 times and got the following results:

  • f2e2 (33 times)
  • d5e4 (16 times)
  • d5e6 (1 time)

Running the same experiment with 0s per move I got:

  • d5e6 (36 times)
  • d5e4 (7 times)
  • b4d3 (6 times)
  • b4c6 (1 time)

So, why the engine gave you Be6, I can’t exactly say, but given the 0s results, I’m guessing that at 1s, the engine just for whatever reason couldn’t advance the search far enough to find the better move.

1 Like
#3

Thank you so much for such a detailed reply, Chendry. I will go through the CSV step-by-step in a spreadsheet to learn and analyse all the positions.

And yes, I also believe the engine couldn’t search deeper for a better move at that position because of the 1 sec think time. So it suggested Be6.

Anyways, I appreciate your effort for this. Thanks for the CSV.

Cheers!