The cause of extreme piece shuffling

[Nordlandia]

"Piece Shuffling" is associated with pieces being moved back and forth for a considerable amount of time/moves. 70 in this case.

Can someone explain why this happend please

In my opinion this simulate some wacky form of "triangulation"

[pgn][Event "EXPERT-LENOVA-1, Slow 150m+60s"]
[Site "EXPERT-LENOVA-1"]
[Date "2016.01.10"]
[Round "1"]
[White "SugaR 2.0 64 POPCNT"]
[Black "Komodo 9.3 64-bit"]
[Result "1-0"]
[ECO "C60"]
[SetUp "1"]
[FEN "4r3/5p1k/p2n1Pp1/Pp1Pp1R1/1P2P2P/3B2P1/2R1K3/2r5 b - - 0 50"]
[PlyCount "168"]

50... Rxc2+ (50... Rxc2+ 51. Bxc2 Kh6 {2.87/45 Stockfish 5 64 SSE4.2}) 51. Bxc2
(51. Bxc2 Nc4 52. Bb3 {3.04/35 Komodo 9.3 64-bit}) 51... Rc8 (51... Kh6 52. Bd3
Nb7 {3.02/31 Fritz 15}) 52. Bd3 (52. Kd3 Re8 53. Bb3 {3.15/40 Komodo 9.3 64-bit
}) 52... Re8 53. Kf2 (53. Ke3 Kh8 54. Kd2 {2.82/48 Stockfish 251115 64 POPCNT})
53... Kh8 (53... Kg8 54. Ke3 Kh7 {3.07/40 Komodo 9.3 64-bit}) 54. Ke3 (54. Ke3
Kh7 55. Bf1 {2.75/50 Stockfish 7 64 POPCNT}) 54... Kh7 55. Kf3 (55. Be2 Kh6 56.
Bd1 {3.19/38 Komodo 9.3 64-bit}) 55... Kh8 (55... Kh6 56. Bf1 Kh7 {3.34/29
Deep Fritz 14 x64}) 56. Bb1 (56. Bf1 Kg8 57. Ke3 {2.33/29 Houdini 3 x64}) 56...
Kg8 (56... Kg8 57. Bd3 Kh7 {2.77/31 Komodo 8 64-bit}) 57. Ke2 (57. Ke2 Kh7 58.
Bd3 {3.25/27 Deep Fritz 14}) 57... Kh7 (57... Kh7 58. Kf3 Kh6 {3.13/36 Komodo
9.1 64-bit}) 58. Kd3 (58. Bd3 Kh6 59. Ke3 {3.32/29 Deep Fritz 14 x64}) 58...
Kh6 (58... Nc4 59. Ke2 Nd6 {3.33/30 Deep Fritz 14}) 59. Ke3 (59. Ke2 Nc4 60.
Bd3 {2.81/49 Stockfish 5 64 SSE4.2}) 59... Kh7 (59... Kh7 60. Bd3 Kg8 {2.67/30
Critter 1.5.38 64-bit}) 60. Bd3 (60. Bd3 Kh6 61. Be2 {3.24/28 Deep Fritz 14 x64
}) 60... Kh6 (60... Kh6 61. Kf3 Kh7 {3.39/31 Deep Fritz 14 x64}) 61. Kf3 (61.
Ke2 Nb7 62. Kf2 {3.07/35 Komodo 9.1 32-bit}) 61... Kh7 (61... Kh7 62. Ke2 Kh8 {
3.12/28 Fritz 11 SE}) 62. Kg2 (62. Ke3 Kh6 63. Be2 {3.37/30 Deep Fritz 14 x64})
62... Kh6 (62... Kh6 63. Kf3 Kh7 {3.25/28 Deep Fritz 14 x64}) 63. Kf2 (63. Kf2
Kh7 64. Kf3 {3.24/26 Deep Fritz 14 x64}) 63... Kh7 64. Bb1 (64. Ke2 Kh6 65. Ke3
{2.91/49 Stockfish 5 64 SSE4.2}) 64... Nc4 (64... Nc8 65. Ke2 Nd6 {2.75/49
Stockfish 6 64 POPCNTsup}) 65. Bc2 (65. Bd3 Nd6 66. Ke3 {3.15/39 Komodo 9.3
64-bit}) 65... Nd6 (65... Nd6 66. Ke2 Kg8 {2.73/40 Stockfish 6 64}) 66. Kf1 (
66. Bd3 Kh6 67. Ke3 {2.89/47 Stockfish 7 64 POPCNT}) 66... Rc8 67. Bd3 (67. Bd3
Re8 68. Ke2 {2.75/46 Stockfish 6 64}) 67... Re8 (67... Re8 68. Ke2 Kh6 {
2.84/46 Stockfish 5 64 SSE4.2}) 68. Ke2 Kg8 (68... Kh6 69. Ke3 Kh7 {3.19/38
Komodo 9.3 64-bit}) 69. Bc2 Kh8 (69... Kh7 70. Bd3 Kh8 {2.65/27 Critter 1.5c
64-bit}) 70. Kd3 (70. Bd3 Kh7 71. Kf3 {3.20/28 Deep Fritz 14 x64}) 70... Kh7 (
70... Kh7 71. Ke2 Nc4 {3.23/34 Komodo 9 64-bit}) 71. Bd1 (71. Ke2 Nc4 72. Bd3 {
2.81/40 Stockfish 050715 64 SSE4.2}) 71... Nc4 (71... Kh6 72. Bb3 Kh7 {2.82/46
Stockfish 251115 64 POPCNT}) 72. Bb3 (72. Be2 Kh6 73. Kc3 {3.15/38 Komodo 9.3
64-bit}) 72... Nd6 73. Bc2 (73. Bd1 Kh6 74. Bc2 {2.67/40 Stockfish 7 64 POPCNT}
) 73... Nc4 (73... Nc4 74. Ke2 {2.70/31 Houdini 4 x64A}) 74. Bb1 (74. Ke2 Nd6
75. Kf3 {3.48/32 Deep Fritz 13}) 74... Kh6 (74... Kh6 75. Ba2 Nd6 {2.72/48
Stockfish 6 64}) 75. Ke2 Kh7 (75... Rc8 76. Bd3 Rb8 {2.18/8 Houdini 2.0c w32})
76. Bc2 (76. Bc2 Nd6 77. Ke3 {3.15/38 Komodo 9.3 64-bit}) 76... Nd6 (76... Nd6
77. Kd3 Kh6 {3.19/37 Komodo 9.3 64-bit}) 77. Ke1 (77. Kd3 Kh6 78. Bb1 {2.83/47
Stockfish 5 64 SSE4.2}) 77... Kh6 (77... Kg8 78. Bd3 Kh7 {3.09/26 Fritz 15})
78. Bd3 (78. Ke2 Rc8 79. Bd3 {3.18/40 Komodo 9.3 64-bit}) 78... Kh7 (78... Kh7
79. Kf2 Nb7 {2.83/46 Stockfish 7 64 POPCNT}) 79. Bb1 (79. Ke2 Kh6 80. Ke3 {
3.35/32 Deep Fritz 14 x64}) 79... Kh8 (79... Nb7 80. Bd3 Nd6 {2.91/37
Stockfish 5 64 SSE4.2}) 80. Kf2 (80. Kf2 Kg8 81. Bd3 {3.20/27 Deep Fritz 14 x64
}) 80... Kh7 (80... Kh7 81. Bd3 Kh6 {2.80/47 Stockfish 5 64 SSE4.2}) 81. Kf1 (
81. Bd3 Kh6 82. Ke3 {3.37/31 Deep Fritz 14 x64}) 81... Kg8 (81... Kg8 82. Ke2
Kh7 {3.02/35 Komodo 9.2 64-bit}) 82. Kg2 Kh7 (82... Kh7 83. Bd3 Kh6 {3.24/29
Deep Fritz 14 x64}) 83. g4 Kh6 (83... Kh6 84. Bd3 Kh7 {2.88/41 Komodo 9.1
64-bit}) 84. Kf3 (84. Kf3 Kh7 85. Bd3 {3.15/29 Deep Fritz 14 x64}) 84... Nc4 (
84... Nb7 85. Ke3 Nd6 {2.61/23 Komodo 8 32-bit}) 85. Bd3 (85. Bd3 Nd6 86. Ke3 {
2.56/46 Stockfish 7 64 POPCNT}) 85... Nd6 (85... Nd6 86. Ke2 Kh7 {3.01/30
Fritz 11 SE}) 86. Ke2 (86. Bf1 Kh7 87. Be2 {3.10/28 Deep Fritz 14 x64}) 86...
Nb7 (86... Kh7 87. Ke3 Kh6 {2.52/45 Stockfish 6 64}) 87. Ke3 (87. Ke3 Nd6 88.
Be2 {2.55/44 Stockfish 160215 64}) 87... Nd6 88. Bb1 (88. Bc2 Kh7 89. Bd1 {
2.57/44 Stockfish 6 64}) 88... Nc4+ (88... Nc4+ 89. Kd3 Kh7 {3.30/27 Deep
Fritz 14 x64}) 89. Ke2 (89. Kd3 Nb2+ 90. Ke2 {3.20/27 Deep Fritz 14 x64}) 89...
Nd6 (89... Kh7 90. Bd3 Nd6 {3.15/29 Deep Fritz 14 x64}) 90. Kd2 (90. Bd3 Kh7
91. Kf3 {3.07/30 Fritz 11 SE}) 90... Nc4+ 91. Kd3 (91. Ke2 Nd6 92. Bd3 {
3.10/27 Deep Fritz 14 x64}) 91... Kh7 (91... Kh7 92. Bc2 Nd6 {2.71/40
Stockfish 6 64}) 92. Ke2 (92. Bc2 Kh6 93. Ke2 {2.96/26 Komodo 9.1 32-bit})
92... Nd6 (92... Kh6 93. Bd3 Nd6 {2.82/36 Komodo 9.3 64-bit}) 93. Ke3 (93. Bd3
Kh6 94. Kf3 {2.94/29 Deep Rybka 4 w32}) 93... Nc4+ (93... Kh6 94. Kd3 Nc4 {
2.81/46 Stockfish 5 64 SSE4.2}) 94. Kd3 (94. Ke2 Kh6 95. Bd3 {2.70/48
Stockfish 251115 64 POPCNT}) 94... Kh6 (94... Kh6 95. Ba2 Nd6 {2.86/36 Komodo
9.3 64-bit}) 95. Bc2 (95. Kc2 Ne3+ 96. Kc1 {2.67/38 Stockfish 5 64 SSE4.2})
95... Kh7 (95... Nd6 96. Ke3 Nc4+ {2.61/30 Critter 1.5.38 64-bit}) 96. Bb3 (96.
Ke2 Kh6 97. Bd3 {3.52/30 Fritz 13}) 96... Nd6 (96... Nd6 97. Bd1 Nc4 {2.81/38
Komodo 9.3 64-bit}) 97. Bd1 (97. Bd1 Kh6 98. Bc2 {2.50/29 Komodo 8 64-bit})
97... Nc4 (97... Nc4 98. Be2 Nd6 {2.81/41 Komodo 9.3 64-bit}) 98. Be2 (98. Bb3
Nd6 99. Bc2 {2.60/50 Stockfish 6 64}) 98... Kh6 (98... Kg8 99. Kc2 Nd6 {
2.84/34 Komodo 9.1 64-bit}) 99. Kc3 (99. Kc3 Nd6 100. Bd3 {2.50/48 Stockfish 5
64 SSE4.2}) 99... Nd6 (99... Nd6 100. Bd3 Rc8+ {3.33/24 Deep Fritz 14}) 100.
Bd3 (100. Bd3 Rc8+ 101. Kd2 {2.64/47 Stockfish 5 64 SSE4.2}) 100... Kh7 (100...
Rc8+ 101. Kd2 Re8 {2.79/34 Komodo 9.1 32-bit}) 101. Kb3 (101. Kd2 Kh6 102. Ke3
{2.71/38 Komodo 9.3 64-bit}) 101... Kh6 102. Kb2 (102. Kc3 Rc8+ 103. Kb2 {
2.69/41 Komodo 9.3 64-bit}) 102... Nb7 (102... Kh7 103. Kc3 Rc8+ {3.24/30 Deep
Fritz 14 x64}) 103. Kc3 (103. Kc3 Nd6 104. Kd2 {3.20/30 Deep Fritz 14 x64})
103... Nd6 (103... Nd6 104. Kd2 Kh7 {2.96/31 Fritz 15}) 104. Kb3 Kh7 (104...
Kh7 105. Kc3 Rc8+ {2.80/37 Komodo 9.2 64-bit}) 105. Kc2 (105. Kb2 Kh6 106. Kc3
{2.38/31 Houdini 4 Pro x64}) 105... Rc8+ (105... Rc8+ 106. Kd2 Re8 {2.94/38
Komodo 9.1 64-bit}) 106. Kd1 (106. Kb2 Re8 107. Kc3 {3.25/30 Deep Fritz 14 x64}
) 106... Re8 (106... Re8 107. Ke2 Nc8 {3.23/29 Deep Fritz 14 x64}) 107. Bb1 (
107. Kd2 Kh6 108. Kc2 {2.66/43 Stockfish 7 64}) 107... Kg8 (107... Kg8 108. Bd3
Kh7 {2.66/47 Stockfish 7 64 POPCNT}) 108. Kd2 (108. Ke2 Kh7 109. Kf2 {2.07/32
Houdini 3 x64}) 108... Kh7 (108... Nc4+ 109. Ke2 Kh7 {2.69/37 Stockfish 050715
64 SSE4.2}) 109. Bc2 (109. Kd3 {2.88/37 Komodo 9.2 64-bit}) 109... Kh6 (109...
Nc4+ 110. Ke2 Nd6 {2.52/31 Houdini 3 w32}) 110. Ke3 (110. Bd3 Kh7 111. Ke3 {
3.10/29 Deep Fritz 14 x64}) 110... Rc8 (110... Kh7 111. Bd3 Kg8 {3.07/29 Deep
Fritz 14 x64}) 111. Bb1 Re8 112. Bd3 (112. Bd3 Kh7 113. Kf3 {2.96/29 Fritz 11
SE}) 112... Kh7 113. Kf2 (113. Be2 Kh6 114. Kf3 {2.81/37 Komodo 9.3 64-bit})
113... Kh6 (113... Kh6 114. Ke3 Kh7 {2.65/46 Stockfish 5 64 SSE4.2}) 114. Kf3 (
114. Ke3 Kh7 115. Be2 {3.20/29 Deep Fritz 14 x64}) 114... Kh7 (114... Kh7 115.
Ke3 Kh6 {2.57/45 Stockfish 6 64}) 115. Ke2 (115. Ke2 Kh6 116. Kd2 {2.70/50
Stockfish 5 64 SSE4.2}) 115... Kh8 (115... Nc8 116. Ke3 Kh6 {3.18/28 Deep
Fritz 14 x64}) 116. Kf2 Kh7 (116... Kh7 117. Ke3 Kh6 {2.52/45 Stockfish 6 64})
117. Kf1 (117. Ke3 Kh6 118. Bf1 {2.51/46 Stockfish 6 64}) 117... Kh8 (117...
Kh8 118. Ke2 Kh7 {3.31/32 Deep Fritz 13}) 118. Kg2 (118. Kf2 Kh7 119. Kf3 {
2.53/48 Stockfish 5 64 SSE4.2}) 118... Kh7 119. Kh2 (119. Kf2 Kh6 120. Ke3 {
2.87/36 Komodo 9.3 64-bit}) 119... Kh6 (119... Kh6 120. Kg2 Nc8 {2.67/36
Komodo 9.3 64-bit}) 120. Kg3 (120. Kg2 Kh7 121. Kg3 {2.80/38 Komodo 9.3 64-bit}
) 120... Kh7 (120... Rc8 121. Kf3 Re8 {3.04/27 Fritz 11 SE}) 121. h5 (121. Kf3
Kh6 122. Ke3 {3.46/31 Deep Fritz 14 x64}) 121... Kh6 (121... Kh6 122. Kh4 {
2.53/34 Stockfish 7 64 POPCNT}) 122. Kh4 (122. Kh4 {2.67/25 Deep Fritz 14 x64})
122... Kh7 123. Be2 (123. Be2 Nxe4 124. hxg6+ {2.70/37 Stockfish 5 64 SSE4.2})
123... Nxe4 (123... Nxe4 124. hxg6+ fxg6 {2.91/24 Houdini 4 x64A}) 124. hxg6+ (
124. hxg6+ fxg6 125. f7 {2.39/31 Komodo 9.3 64-bit}) 124... fxg6 (124... fxg6
125. f7 Rh8 {3.01/20 Fritz 15}) 125. f7 (125. f7 {2.28/20 Komodo 8 64-bit})
125... Rh8 (125... Rh8 126. f8=R Rxf8 {2.74/23 Deep Fritz 14}) 126. f8=R (126.
f8=R Rxf8 127. Rxe5 {2.48/34 Stockfish 160215 64}) 126... Rxf8 (126... Rxf8
127. Rxe5 g5+ {2.50/20 Critter 1.5c 64-bit}) 127. Rxe5 (127. Rxe5 Rf4 128. Re6
{2.82/29 Komodo 9.3 64-bit}) 127... Rf4 (127... Rf4 128. Re6 {3.04/25 Deep
Fritz 14 x64}) 128. Re6 (128. Re6 {3.42/27 Stockfish 7 64 POPCNT}) 128... Kg7 (
128... Nc3 129. Bd3 {3.13/23 Deep Fritz 14 x64}) 129. Bxb5 axb5 (129... axb5
130. a6 {2.26/25 Komodo 9 64-bit}) 130. a6 (130. a6 {4.94/28 Stockfish 7 64
POPCNT}) 130... g5+ (130... g5+ 131. Kh5 {3.58/39 Stockfish 6 64}) 131. Kh5 (
131. Kh5 Nf6+ 132. Kxg5 {3.71/26 Houdini 3 x64}) 131... Kf7 (131... Nf6+ 132.
Kxg5 Rxg4+ {3.47/24 Deep Fritz 14 x64}) 132. a7 (132. a7 Rf2 133. Rxe4 {
109.62/35 Stockfish 5 64 SSE4.2}) 132... Rf2 (132... Rf3 133. Rxe4 Ra3 {
9.19/27 Deep Fritz 14 x64}) 133. Rxe4 (133. Rxe4 {6.01/24 Deep Fritz 14 x64})
133... Ra2 (133... Ra2 134. Kxg5 {10.20/25 Deep Fritz 14 x64}) 134. Kxg5 (134.
Kxg5 Rxa7 135. d6 {7.56/28 Deep Fritz 14 x64}) 1-0[/pgn]

[hgm]

When engines don't see a way to make progress, but can easily defend against the opponent making progress, they just randomly pick one of the moves that maintain the status quo. They have no tendency to organize their own pieces in what they would consider the optimal way, and are prepared to move to positions they actuall consider pretty poor, as long as they see that within their search horizon they will be able to move back to that optimum. So they basically just make a random walk in the region of game-state space that surrounds the perceived local optimum with a maximum distance of their search depth.

A delayed-loss bonus would give them an incentive to actually move towards the local optimum, from which they might be able to see a way to make progress (while far away from it they need all their depth to worry about how to get to that local optimum, and can certainly not see what lies behind it). But not many engines have that.

[Nordlandia]

Here is the full game.

[pgn][Event "EXPERT-LENOVA-1, Slow 150m+60s"]
[Site "EXPERT-LENOVA-1"]
[Date "2016.01.10"]
[Round "1"]
[White "SugaR 2.0 64 POPCNT"]
[Black "Komodo 9.3 64-bit"]
[Result "1-0"]
[ECO "C60"]
[Annotator "0.38;0.22"]
[PlyCount "267"]
[TimeControl "9000+60"]

{Intel(R) Core(TM) i5-5200U CPU @ 2.20GHz 2194 MHz W=39.6 plies; 2,951kN/s; 8,
255,934 TBAs B=35.4 plies; 2,893kN/s; 23,148,237 TBAs} 1. e4 {Both last book
move} e5 2. Nf3 Nc6 3. Bb5 Nge7 4. O-O {0.38/31 285} g6 {0.22/27 173} 5. c3 {
0.28/33 280} a6 {0.21/29 193} 6. Ba4 {0.25/34 419 (Bc4)} Bg7 {0.21/30 284} 7.
d4 {0.24/31 67} exd4 {0.21/29 400} 8. cxd4 {0.28/33 151} O-O {0.18/29 219} 9.
d5 {0.17/27 39 (Bxc6)} Na5 {0.14/27 154} 10. Nc3 {0.16/31 465 (Re1)} b5 {
0.12/29 527 (d6)} 11. Bc2 {0.13/32 302 (Bb3)} d6 {0.12/27 109} 12. Rb1 {
0.27/32 392 (h3)} Re8 {0.13/29 231 (Nc4)} 13. Re1 {0.10/31 519} Bg4 {0.18/29
475 (Nc4)} 14. h3 {0.20/32 238} Bxf3 {0.22/30 258} 15. Qxf3 {0.21/33 121} c5 {
0.13/32 228 (Nc4)} 16. b3 {0.34/31 320 (dxc6)} Nf5 {0.22/29 231} 17. Ne2 {
0.22/33 229} Nd4 {0.23/28 102} 18. Nxd4 {0.23/31 41} Bxd4 {0.22/29 385} 19. Be3
{0.34/31 239} Bg7 {0.21/28 206 (Bxe3)} 20. g3 {0.42/30 106 (Qe2)} c4 {0.32/30
234} 21. h4 {0.49/32 670 (Rec1)} h5 {0.30/28 143 (Qd7)} 22. Kg2 {0.56/29 143
(Rec1)} Qd7 {0.37/31 375 (Qc8)} 23. Qd1 {0.68/29 182 (Rec1)} Rec8 {0.51/29 637}
24. b4 {0.77/34 276 (Re2)} Nb7 {0.60/28 143} 25. a4 {0.82/32 80} Bc3 {0.60/28
236} 26. Bd2 {0.84/32 144} Bh8 {0.65/29 398 (Bd4)} 27. a5 {0.91/32 131 (Re2)}
Re8 {0.95/30 345} 28. Be3 {0.96/31 77} Re7 {0.93/31 355 (Qe7)} 29. f4 {1.13/30
196 (Bd4)} Bc3 {1.00/30 356} 30. Bd2 {1.13/34 136 (Rh1)} Bf6 {1.14/31 378
(Bxd2)} 31. f5 {1.38/31 188} Be5 {1.27/29 282} 32. Rf1 {1.55/33 877} Nd8 {
1.41/29 599 (Kg7)} 33. f6 {1.90/33 155 (Be3)} Re8 {1.66/31 122} 34. Qf3 {
2.05/31 68} c3 {2.35/31 272} 35. Bxc3 {2.09/35 215} Rc8 {2.35/31 150} 36. Rb3 {
2.15/31 35} Rc4 {2.41/34 172} 37. Rf2 {2.34/33 252 (Qe3)} Qc8 {2.62/31 264
(Kh7)} 38. Bxe5 {2.46/37 223} dxe5 {2.32/32 186} 39. Bd3 {2.53/31 36} Rc1 {
2.71/32 137} 40. Qe3 {2.63/35 120} Kh7 {2.86/31 51} 41. Qe2 {2.70/31 41} Nb7 {
2.42/32 109 (Qc7)} 42. Rf5 {2.92/35 212} Ra1 {2.92/33 104} 43. Rxh5+ {2.93/34
31} Kg8 {3.09/34 73} 44. Qb2 {2.93/36 95 (Qe3)} Qc1 {3.01/38 159} 45. Qxc1 {
2.93/38 73} Rxc1 {3.10/34 57} 46. Rg5 {2.93/40 118} Nd6 {3.11/36 108} 47. Kf2 {
2.93/40 151} Kh7 {3.03/36 135 (Kh8)} 48. Ke2 {2.93/40 103} Kh6 {3.02/37 244
(Nc4)} 49. Rb2 {2.93/39 155 (Rb1)} Kh7 {3.03/39 138 (Nc4)} 50. Rc2 {2.93/43 208
} Rxc2+ {3.03/40 47} 51. Bxc2 {2.93/46 33} Rc8 {3.04/37 44 (Kh6)} 52. Bd3 {
2.93/41 207} Re8 {3.04/41 55} 53. Kf2 {2.93/45 72 (Kf3)} Kh8 {3.04/41 51 (Kg8)}
54. Ke3 {2.93/48 82 (Kf3)} Kh7 {3.03/39 235} 55. Kf3 {2.93/52 84 (Be2)} Kh8 {
3.04/34 97 (Kh6)} 56. Bb1 {2.93/49 244 (Kf2)} Kg8 {3.03/38 42 (Kh7)} 57. Ke2 {
2.93/51 102 (Kg2)} Kh7 {3.10/41 55} 58. Kd3 {2.93/52 38 (Bd3)} Kh6 {3.04/42 101
} 59. Ke3 {2.93/52 90 (Bc2)} Kh7 {3.04/42 115} 60. Bd3 {2.93/52 78} Kh6 {
3.04/43 66 (Kg8)} 61. Kf3 {2.93/50 335 (Kd2)} Kh7 {3.04/42 70} 62. Kg2 {
2.93/49 24 (Be2)} Kh6 {3.07/42 102 (Kh8)} 63. Kf2 {2.93/46 70} Kh7 {3.07/41 35}
64. Bb1 {2.93/45 26 (Ke2)} Nc4 {3.11/43 106 (Kg8)} 65. Bc2 {2.93/48 84 (Ke1)}
Nd6 {3.10/41 144 (Kh6)} 66. Kf1 {2.93/43 118 (Ke3)} Rc8 {3.08/37 55 (Kh6)} 67.
Bd3 {2.93/42 75} Re8 {3.06/40 54} 68. Ke2 {2.93/44 27 (Ke1)} Kg8 {3.07/39 49
(Kh6)} 69. Bc2 {2.93/45 118} Kh8 {3.02/38 85 (Kh7)} 70. Kd3 {2.93/45 75 (Ke3)}
Kh7 {3.03/37 32} 71. Bd1 {2.93/44 34} Nc4 {3.03/39 84 (Kh6)} 72. Bb3 {2.93/50
143 (Be2)} Nd6 {3.03/39 47} 73. Bc2 {2.93/51 22 (Ba2)} Nc4 {3.02/39 112 (Kh6)}
74. Bb1 {2.93/48 73 (Ke2)} Kh6 {3.02/41 75 (Nd6)} 75. Ke2 {2.93/48 161} Kh7 {
3.02/39 141 (Nd6)} 76. Bc2 {2.93/45 78 (Ba2)} Nd6 {2.99/34 31 (Kg8)} 77. Ke1 {
2.93/39 108} Kh6 {2.94/37 44 (Kg8)} 78. Bd3 {2.87/43 234} Kh7 {2.84/38 43} 79.
Bb1 {2.93/43 112 (Kd2)} Kh8 {2.87/35 77 (Kh6)} 80. Kf2 {2.93/43 150 (Bc2)} Kh7
{2.82/34 32} 81. Kf1 {2.84/41 231} Kg8 {2.78/36 79 (Kh6)} 82. Kg2 {2.75/41 129
(Bc2)} Kh7 {2.79/38 85} 83. g4 {2.74/38 67 (Kh2)} Kh6 {2.77/41 81 (Kh8)} 84.
Kf3 {2.74/46 57 (Bd3)} Nc4 {2.72/40 142 (Kh7)} 85. Bd3 {2.74/50 69 (Kf2)} Nd6 {
2.78/38 40} 86. Ke2 {2.74/48 139 (Kf2)} Nb7 {2.79/38 34 (Kh7)} 87. Ke3 {
2.74/41 61} Nd6 {2.73/38 28} 88. Bb1 {2.74/46 24 (Kf3)} Nc4+ {2.74/38 37 (Kh7)}
89. Ke2 {2.74/50 53 (Kf2)} Nd6 {2.73/40 47} 90. Kd2 {2.74/51 58 (Kd3)} Nc4+ {
2.73/38 47 (Kh7)} 91. Kd3 {2.74/49 50 (Ke1)} Kh7 {2.73/39 49 (Nd6)} 92. Ke2 {
2.74/50 68 (Ba2)} Nd6 {2.74/42 63} 93. Ke3 {2.74/43 17} Nc4+ {2.74/41 95 (Kh6)}
94. Kd3 {2.74/46 65 (Kf2)} Kh6 {2.74/39 75 (Nd6)} 95. Bc2 {2.74/50 63 (Ba2)}
Kh7 {2.76/41 49 (Nd6)} 96. Bb3 {2.74/50 67 (Ke2)} Nd6 {2.74/39 32} 97. Bd1 {
2.74/52 25} Nc4 {2.74/39 46} 98. Be2 {2.74/52 54} Kh6 {2.74/40 131 (Nd6)} 99.
Kc3 {2.74/49 67} Nd6 {2.74/39 32} 100. Bd3 {2.74/51 30} Kh7 {2.74/42 49 (Rc8+)}
101. Kb3 {2.74/49 53} Kh6 {2.74/42 31} 102. Kb2 {2.74/52 86} Nb7 {2.71/41 75}
103. Kc3 {2.74/52 37 (Kc2)} Nd6 {2.74/40 87 (Rc8+)} 104. Kb3 {2.74/42 57 (Kc2)}
Kh7 {2.76/39 84} 105. Kc2 {2.74/42 36} Rc8+ {2.73/37 35} 106. Kd1 {2.74/46 89}
Re8 {2.73/41 44} 107. Bb1 {2.74/49 580 (Kd2)} Kg8 {2.72/38 52 (Nb7)} 108. Kd2 {
2.70/47 145 (Kc1)} Kh7 {2.73/42 44} 109. Bc2 {2.70/46 271 (Bd3)} Kh6 {2.71/35
33} 110. Ke3 {2.70/39 31} Rc8 {2.71/32 34} 111. Bb1 {2.70/40 64 (Kd3)} Re8 {
2.72/42 145} 112. Bd3 {2.70/42 46 (Kf2)} Kh7 {2.72/41 112 (Nb7)} 113. Kf2 {
2.70/39 36 (Bf1)} Kh6 {2.59/39 99} 114. Kf3 {2.63/38 14 (Bb1)} Kh7 {2.59/38 63
(Nb7)} 115. Ke2 {2.70/40 73 (Bf1)} Kh8 {2.59/35 68 (Nb7)} 116. Kf2 {2.59/39
201 (Bc2)} Kh7 {2.27/35 72} 117. Kf1 {2.62/37 63 (Ke1)} Kh8 {2.41/35 96 (Kh6)}
118. Kg2 {2.70/32 80} Kh7 {2.26/33 28 (Kg8)} 119. Kh2 {2.53/36 60 (Kg1)} Kh6 {
2.26/32 44} 120. Kg3 {2.21/38 84 (Kg1)} Kh7 {1.93/31 37 (Nb7)} 121. h5 {
2.63/30 30} Kh6 {2.71/32 54} 122. Kh4 {2.71/31 22} Kh7 {3.07/32 56} 123. Be2 {
2.74/33 42} Nxe4 {3.07/33 43} 124. hxg6+ {2.78/30 16} fxg6 {3.21/34 79} 125. f7
{2.81/33 29} Rh8 {3.31/33 52} 126. f8=R {2.98/31 69 (f8Q)} Rxf8 {3.31/31 43}
127. Rxe5 {3.05/28 10} Rf4 {3.32/33 89} 128. Re6 {3.05/30 32 (Bxb5)} Kg7 {
2.45/29 78} 129. Bxb5 {3.14/27 14} axb5 {3.66/30 238 (Nf6)} 130. a6 {4.37/27 44
} g5+ {4.62/31 78} 131. Kh5 {4.56/24 14} Kf7 {6.53/25 39 (Nf6+)} 132. a7 {
38.96/33 43} Rf2 {250.00/46 23 (Rf3)} 133. Rxe4 {123.38/40 44} Ra2 {250.00/45
23} 134. Kxg5 {123.41/44 15} 1-0[/pgn]

[Marek Soszynski]

A delayed-loss bonus would give [engines] an incentive to actually move towards the local optimum, from which they might be able to see a way to make progress (while far away from it they need all their depth to worry about how to get to that local optimum, and can certainly not see what lies behind it). But not many engines have that.

Which engines do?

[hgm]

I know that Fairy-Max/micro-Max, Joker, Spartacus, KingSlayer, HaQiKi D, Shokidoki, HaChu all do it.

[Evert]

I know that Fairy-Max/micro-Max, Joker, Spartacus, KingSlayer, HaQiKi D, Shokidoki, HaChu all do it.

I sense a pattern!