Stockfish bug in 50 moves rule found (or arena bug)

[Nay Lin Tun]

This game was played Xipho vs Lco in cccc and I analysed with 10/09/2018 stockfish without TB. At move 98. Xipho played Be4+ and lose.
I analysed 98. Bd7 line and SF see draw at move 103. Bd1 50 move rules. 0.00 evaluation . In fact it is loss.
[pgn][Event "CCCC 1: Rapid Rumble (15|5) Stage 1"] [Site "Chess.com"] [Date "2018.09.10"] [Round "?"] [White "Xiphos 0.3.17"] [Black "Lc0 17.11089"] [Result "0-1"] [BlackElo "2400"] [ECO "B53"] [Opening "Sicilian, Chekhover, 4...Nf6"] [Time "17:12:56"] [WhiteElo "2400"] [TimeControl "900+5"] [Termination "normal"] [PlyCount "205"] [WhiteType "human"] [BlackType "human"] 1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Qxd4 Nf6 5. c4 Nc6 6. Qd3 g6 7. Nc3 Bg7 8. Be2 Bg4 9. O-O Bxf3 10. Bxf3 Ne5 11. Qd1 Rc8 12. Be2 Nxc4 13. Qa4+ Qd7 14. Qxa7 O-O 15. Rd1 Qe6 16. f3 d5 17. Nxd5 Nxd5 18. Rxd5 Nxb2 19. Rb1 Qc6 20. Bxb2 Bxb2 21. Qe3 e6 22. Rdd1 Bf6 23. g3 Rfd8 24. Rxd8+ Rxd8 25. Kf1 Rc8 26. Kg2 h5 27. Kh3 Kg7 28. e5 Be7 29. f4 h4 30. Bf3 Qc2 31. Qb3 Qf2 32. Rb2 Qf1+ 33. Bg2 Qc1 34. Rb1 Qc5 35. Qxb7 g5 36. Rc1 Qxc1 37. Qxe7 hxg3 38. Qxg5+ Kf8 39. hxg3 Qc2 40. Bb7 Qh7+ 41. Kg4 Rb8 42. Bc6 Qg7 43. Qxg7+ Kxg7 44. a4 Rb3 45. f5 Rb4+ 46. Kg5 Rc4 47. Bb7 Rxa4 48. g4 Rc4 49. Bg2 Rb4 50. Bc6 Rd4 51. Bg2 Rc4 52. Bb7 Rc3 53. f6+ Kf8 54. Be4 Rc1 55. Bd3 Rd1 56. Be4 Rf1 57. Bd3 Rf2 58. Be4 Ke8 59. Ba8 Rf1 60. Be4 Rf2 61. Bc6+ Kf8 62. Be4 Kg8 63. Bd3 Rf3 64. Be4 Rf1 65. Bd3 Rf2 66. Be4 Kh8 67. Bb7 Kh7 68. Be4+ Kh8 69. Bd3 Rf3 70. Bb1 Rf1 71. Be4 Kg8 72. Bd3 Rf2 73. Be4 Kf8 {3-fold repetition} 74. Bc6 Rf1 75. Be4 Rf2 {3-fold repetition} 76. Bc6 Ra2 77. Kf4 Ra1 78. Kg5 Rc1 79. Be4 Rf1 80. Bb7 Kg8 81. Be4 {3-fold repetition} Kh8 82. Bd3 Rd1 83. Be4 Kg8 84. Kf4 Rf1+ 85. Ke3 Ra1 86. Kf4 Kf8 87. Kg5 Rg1 88. Bf3 Re1 89. Kf4 Rf1 90. Ke3 Ra1 91. Kf4 Rf1 92. Ke3 Rb1 93. Ke4 Kg8 94. Ke3 Rg1 95. Kf4 Rf1 96. Ke3 Kh7 97. Bc6 Rc1 98. Bd7 Kg6 99. Be8 Rc8 100. Bb5 Kg5 101. Be2 Rc1 102. Kd2 Rb1 103. Bd1 {50 moves rule} 0-1 [/pgn]

https://ibb.co/ijR5FU


Note :There are also multiple 3 folds rep by Arena, confusing!

[Nay Lin Tun]

Never mind! Last capture was 53. So I think 50 move rule is at 103. The position is a loss for white but draw by 50 moves rule.

[Colin-G]

Never mind! Last capture was 53. So I think 50 move rule is at 103. The position is a loss for white but draw by 50 moves rule.

It was the "last pawn move" at move 53, not "last capture", that invoked the 50 move rule at 103.

[zullil]

This game was played Xipho vs Lco in cccc and I analysed with 10/09/2018 stockfish without TB. At move 98. Xipho played Be4+ and lose.
I analysed 98. Bd7 line and SF see draw at move 103. Bd1 50 move rules. 0.00 evaluation . In fact it is loss.
[pgn][Event "CCCC 1: Rapid Rumble (15|5) Stage 1"] [Site "Chess.com"] [Date "2018.09.10"] [Round "?"] [White "Xiphos 0.3.17"] [Black "Lc0 17.11089"] [Result "0-1"] [BlackElo "2400"] [ECO "B53"] [Opening "Sicilian, Chekhover, 4...Nf6"] [Time "17:12:56"] [WhiteElo "2400"] [TimeControl "900+5"] [Termination "normal"] [PlyCount "205"] [WhiteType "human"] [BlackType "human"] 1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Qxd4 Nf6 5. c4 Nc6 6. Qd3 g6 7. Nc3 Bg7 8. Be2 Bg4 9. O-O Bxf3 10. Bxf3 Ne5 11. Qd1 Rc8 12. Be2 Nxc4 13. Qa4+ Qd7 14. Qxa7 O-O 15. Rd1 Qe6 16. f3 d5 17. Nxd5 Nxd5 18. Rxd5 Nxb2 19. Rb1 Qc6 20. Bxb2 Bxb2 21. Qe3 e6 22. Rdd1 Bf6 23. g3 Rfd8 24. Rxd8+ Rxd8 25. Kf1 Rc8 26. Kg2 h5 27. Kh3 Kg7 28. e5 Be7 29. f4 h4 30. Bf3 Qc2 31. Qb3 Qf2 32. Rb2 Qf1+ 33. Bg2 Qc1 34. Rb1 Qc5 35. Qxb7 g5 36. Rc1 Qxc1 37. Qxe7 hxg3 38. Qxg5+ Kf8 39. hxg3 Qc2 40. Bb7 Qh7+ 41. Kg4 Rb8 42. Bc6 Qg7 43. Qxg7+ Kxg7 44. a4 Rb3 45. f5 Rb4+ 46. Kg5 Rc4 47. Bb7 Rxa4 48. g4 Rc4 49. Bg2 Rb4 50. Bc6 Rd4 51. Bg2 Rc4 52. Bb7 Rc3 53. f6+ Kf8 54. Be4 Rc1 55. Bd3 Rd1 56. Be4 Rf1 57. Bd3 Rf2 58. Be4 Ke8 59. Ba8 Rf1 60. Be4 Rf2 61. Bc6+ Kf8 62. Be4 Kg8 63. Bd3 Rf3 64. Be4 Rf1 65. Bd3 Rf2 66. Be4 Kh8 67. Bb7 Kh7 68. Be4+ Kh8 69. Bd3 Rf3 70. Bb1 Rf1 71. Be4 Kg8 72. Bd3 Rf2 73. Be4 Kf8 {3-fold repetition} 74. Bc6 Rf1 75. Be4 Rf2 {3-fold repetition} 76. Bc6 Ra2 77. Kf4 Ra1 78. Kg5 Rc1 79. Be4 Rf1 80. Bb7 Kg8 81. Be4 {3-fold repetition} Kh8 82. Bd3 Rd1 83. Be4 Kg8 84. Kf4 Rf1+ 85. Ke3 Ra1 86. Kf4 Kf8 87. Kg5 Rg1 88. Bf3 Re1 89. Kf4 Rf1 90. Ke3 Ra1 91. Kf4 Rf1 92. Ke3 Rb1 93. Ke4 Kg8 94. Ke3 Rg1 95. Kf4 Rf1 96. Ke3 Kh7 97. Bc6 Rc1 98. Bd7 Kg6 99. Be8 Rc8 100. Bb5 Kg5 101. Be2 Rc1 102. Kd2 Rb1 103. Bd1 {50 moves rule} 0-1 [/pgn]

https://ibb.co/ijR5FU


Note :There are also multiple 3 folds rep by Arena, confusing!

The final pawn move or capture seems to be 53. f6+. So when Stockfish plays 103. Bd1, each side has played 50 times without moving a pawn or capturing. So, when presented with the position after 102...Rb1, my Stockfish-dev says

0.00 103. Bd1 (depth 127, 0:00:00)

So I don't understand what you are reporting.

[Spliffjiffer]

probably he anticipated RxB and wins the endgame but its 1 move too late for that....SF can count to 50

[Guenther]

Never mind! Last capture was 53. So I think 50 move rule is at 103. The position is a loss for white but draw by 50 moves rule.

Your assumed '3 time rep' is also wrong, but I only checked the first one tough (quite sure all are wrong)
In case you don't know the repetition rule:
you need 3 times the same position and the same side to move!

This is not the case for 58.Be4 62.Be4 73...Kf8