Q Not a number

[hans-ekbrand]

Below is an extract from the log where the best move was the only move with children. However, Q of this move was not a number. Something went wrong when backpropagating?

The UCI info says the move had cp 61 after 2910 nodes (perhaps no more search was done after that, since the limit was 3.000 nodes).

0323 22:50:46.578949 139810026174272 ../../src/chess/uciloop.cc:131] >> position startpos moves d2d4 g8f6 c2c4 c7c5 d4d5 e7e6 b1c3 e6d5 c4d5 d7d6 e2e4 g7g6 g1f3 f8g7 f1e2 e8g8 e1g1 b8a6 c1f4 f6h5 f4g5 g7f6 g5h6 f6g7 h6g7 h5g7 e2a6 b7a6 d1d3 a8b8 b2b3 b8b4 f1e1 g7h5 e4e5 d6e5 e1e5 c8g4 h2h3 g4f3
0323 22:50:46.579098 139810026174272 ../../src/chess/uciloop.cc:131] >> isready
0323 22:50:46.579132 139810026174272 ../../src/chess/uciloop.cc:218] << readyok
0323 22:50:46.582269 139810026174272 ../../src/chess/uciloop.cc:131] >> go ponder nodes 3000
0323 22:50:46.582404 139810026174272 ../../src/engine.cc:377] Limits: visits:3000 playouts:-1 depth:-1 infinite:1
0323 22:50:47.142107 139809536763648 ../../src/chess/uciloop.cc:218] << info depth 7 seldepth 12 time 559 nodes 2109 score cp 133 hashfull 0 nps 1432 tbhits 0 pv d3f3 h5f6 g2g3
0323 22:50:47.699906 139808827500288 ../../src/mcts_replace/search.cc:169] Cast my VETO against an uncertain move
0323 22:50:47.699950 139808827500288 ../../src/mcts_replace/search.cc:169] Cast my VETO against an uncertain move
0323 22:50:47.699961 139808827500288 ../../src/mcts_replace/search.cc:169] Cast my VETO against an uncertain move
0323 22:50:47.699970 139808827500288 ../../src/mcts_replace/search.cc:169] Cast my VETO against an uncertain move
0323 22:50:47.699980 139808827500288 ../../src/mcts_replace/search.cc:169] Cast my VETO against an uncertain move
0323 22:50:47.700041 139808827500288 ../../src/chess/uciloop.cc:218] << info depth 7 seldepth 13 time 1117 nodes 2910 score cp 61 hashfull 0 nps 1434 tbhits 0 pv d3f3 h5f6 e5e3 d8d6 a1d1 f8d8 c3e4 f6e4 e3e4
0323 22:50:48.216505 139810026174272 ../../src/chess/uciloop.cc:131] >> ponderhit
0323 22:50:48.216715 139810026174272 ../../src/engine.cc:377] Limits: visits:3000 playouts:-1 depth:-1 infinite:0
0323 22:50:48.256476 139808827500288 ../../src/mcts_replace/search.cc:368] === Move stats:
0323 22:50:48.256504 139808827500288 ../../src/mcts_replace/search.cc:369] d3f3  (513 ) N:    2514 (+2514) (P: 99.73%) (Q:     -nan) (U:   -nan) (Q+U:     -nan) (V:  -.----)
0323 22:50:48.256516 139808827500288 ../../src/mcts_replace/search.cc:369] d3e3  (512 ) N:       1 (+ 1) (P:  0.02%) (Q: -0.31951) (U: -0.31951) (Q+U: -0.63902) (V:  -.----)
0323 22:50:48.256525 139808827500288 ../../src/mcts_replace/search.cc:369] d3d1  (501 ) N:       1 (+ 1) (P:  0.01%) (Q: -0.99650) (U: -0.99650) (Q+U: -1.99301) (V:  -.----)
0323 22:50:48.256534 139808827500288 ../../src/mcts_replace/search.cc:369] g2f3  (373 ) N:       1 (+ 1) (P:  0.01%) (Q: -0.48901) (U: -0.48901) (Q+U: -0.97803) (V:  -.----)
0323 22:50:48.256543 139808827500288 ../../src/mcts_replace/search.cc:369] d3d2  (506 ) N:       1 (+ 1) (P:  0.01%) (Q: -0.90761) (U: -0.90761) (Q+U: -1.81522) (V:  -.----)
0323 22:50:48.256552 139808827500288 ../../src/mcts_replace/search.cc:369] e5e4  (1030) N:       1 (+ 1) (P:  0.01%) (Q: -0.98070) (U: -0.98070) (Q+U: -1.96140) (V:  -.----)
0323 22:50:48.256561 139808827500288 ../../src/mcts_replace/search.cc:369] g2g3  (374 ) N:       1 (+ 1) (P:  0.01%) (Q: -0.63182) (U: -0.63182) (Q+U: -1.26363) (V:  -.----)
0323 22:50:48.256570 139808827500288 ../../src/mcts_replace/search.cc:369] h3h4  (642 ) N:       1 (+ 1) (P:  0.01%) (Q: -0.93077) (U: -0.93077) (Q+U: -1.86154) (V:  -.----)
0323 22:50:48.256579 139808827500288 ../../src/mcts_replace/search.cc:369] a1b1  (0   ) N:       1 (+ 1) (P:  0.01%) (Q: -0.80227) (U: -0.80227) (Q+U: -1.60454) (V:  -.----)
0323 22:50:48.256588 139808827500288 ../../src/mcts_replace/search.cc:369] e5e6  (1042) N:       1 (+ 1) (P:  0.01%) (Q: -0.96948) (U: -0.96948) (Q+U: -1.93895) (V:  -.----)
0323 22:50:48.256597 139808827500288 ../../src/mcts_replace/search.cc:369] d5d6  (1007) N:       1 (+ 1) (P:  0.01%) (Q: -0.90910) (U: -0.90910) (Q+U: -1.81821) (V:  -.----)
0323 22:50:48.256623 139808827500288 ../../src/mcts_replace/search.cc:369] g2g4  (378 ) N:       1 (+ 1) (P:  0.01%) (Q: -0.91889) (U: -0.91889) (Q+U: -1.83778) (V:  -.----)
0323 22:50:48.256633 139808827500288 ../../src/mcts_replace/search.cc:369] a2a3  (204 ) N:       1 (+ 1) (P:  0.01%) (Q: -0.50181) (U: -0.50181) (Q+U: -1.00362) (V:  -.----)
0323 22:50:48.256642 139808827500288 ../../src/mcts_replace/search.cc:369] e5f5  (1037) N:       1 (+ 1) (P:  0.01%) (Q: -0.92589) (U: -0.92589) (Q+U: -1.85179) (V:  -.----)
0323 22:50:48.256651 139808827500288 ../../src/mcts_replace/search.cc:369] g1h1  (153 ) N:       1 (+ 1) (P:  0.01%) (Q: -0.88659) (U: -0.88659) (Q+U: -1.77318) (V:  -.----)
0323 22:50:48.256659 139808827500288 ../../src/mcts_replace/search.cc:369] a1d1  (2   ) N:       1 (+ 1) (P:  0.01%) (Q: -0.97733) (U: -0.97733) (Q+U: -1.95465) (V:  -.----)
0323 22:50:48.256668 139808827500288 ../../src/mcts_replace/search.cc:369] a1c1  (1   ) N:       1 (+ 1) (P:  0.01%) (Q: -0.81680) (U: -0.81680) (Q+U: -1.63360) (V:  -.----)
0323 22:50:48.256677 139808827500288 ../../src/mcts_replace/search.cc:369] d3d4  (518 ) N:       1 (+ 1) (P:  0.01%) (Q: -0.98727) (U: -0.98727) (Q+U: -1.97454) (V:  -.----)
0323 22:50:48.256686 139808827500288 ../../src/mcts_replace/search.cc:369] a2a4  (207 ) N:       1 (+ 1) (P:  0.01%) (Q: -0.89262) (U: -0.89262) (Q+U: -1.78525) (V:  -.----)
0323 22:50:48.256695 139808827500288 ../../src/mcts_replace/search.cc:369] d3e4  (519 ) N:       1 (+ 1) (P:  0.01%) (Q: -0.99324) (U: -0.99324) (Q+U: -1.98648) (V:  -.----)
0323 22:50:48.256704 139808827500288 ../../src/mcts_replace/search.cc:369] a1e1  (3   ) N:       1 (+ 1) (P:  0.01%) (Q: -0.70436) (U: -0.70436) (Q+U: -1.40873) (V:  -.----)
0323 22:50:48.256712 139808827500288 ../../src/mcts_replace/search.cc:369] d3e2  (507 ) N:       1 (+ 1) (P:  0.00%) (Q: -0.99372) (U: -0.99372) (Q+U: -1.98743) (V:  -.----)
0323 22:50:48.256721 139808827500288 ../../src/mcts_replace/search.cc:369] c3e4  (487 ) N:       1 (+ 1) (P:  0.00%) (Q: -0.94239) (U: -0.94239) (Q+U: -1.88477) (V:  -.----)
0323 22:50:48.256730 139808827500288 ../../src/mcts_replace/search.cc:369] g1f1  (152 ) N:       1 (+ 1) (P:  0.00%) (Q: -0.86010) (U: -0.86010) (Q+U: -1.72020) (V:  -.----)
0323 22:50:48.256739 139808827500288 ../../src/mcts_replace/search.cc:369] e5h5  (1039) N:       1 (+ 1) (P:  0.00%) (Q: -0.78907) (U: -0.78907) (Q+U: -1.57814) (V:  -.----)
0323 22:50:48.256748 139808827500288 ../../src/mcts_replace/search.cc:369] g1h2  (157 ) N:       1 (+ 1) (P:  0.00%) (Q: -0.91209) (U: -0.91209) (Q+U: -1.82418) (V:  -.----)
0323 22:50:48.256756 139808827500288 ../../src/mcts_replace/search.cc:369] e5e7  (1047) N:       1 (+ 1) (P:  0.00%) (Q: -0.94195) (U: -0.94195) (Q+U: -1.88391) (V:  -.----)
0323 22:50:48.256765 139808827500288 ../../src/mcts_replace/search.cc:369] e5e8  (1051) N:       1 (+ 1) (P:  0.00%) (Q: -0.74957) (U: -0.74957) (Q+U: -1.49914) (V:  -.----)
0323 22:50:48.256774 139808827500288 ../../src/mcts_replace/search.cc:369] e5e2  (1021) N:       1 (+ 1) (P:  0.00%) (Q: -0.98560) (U: -0.98560) (Q+U: -1.97120) (V:  -.----)
0323 22:50:48.256783 139808827500288 ../../src/mcts_replace/search.cc:369] e5e3  (1025) N:       1 (+ 1) (P:  0.00%) (Q: -0.79379) (U: -0.79379) (Q+U: -1.58758) (V:  -.----)
0323 22:50:48.256792 139808827500288 ../../src/mcts_replace/search.cc:369] d3f5  (525 ) N:       1 (+ 1) (P:  0.00%) (Q: -0.97702) (U: -0.97702) (Q+U: -1.95404) (V:  -.----)
0323 22:50:48.256801 139808827500288 ../../src/mcts_replace/search.cc:369] d3f1  (503 ) N:       1 (+ 1) (P:  0.00%) (Q: -0.86219) (U: -0.86219) (Q+U: -1.72438) (V:  -.----)
0323 22:50:48.256810 139808827500288 ../../src/mcts_replace/search.cc:369] c3a4  (483 ) N:       1 (+ 1) (P:  0.00%) (Q: -0.91177) (U: -0.91177) (Q+U: -1.82355) (V:  -.----)
0323 22:50:48.256819 139808827500288 ../../src/mcts_replace/search.cc:369] d3c2  (505 ) N:       1 (+ 1) (P:  0.00%) (Q: -0.92026) (U: -0.92026) (Q+U: -1.84052) (V:  -.----)
0323 22:50:48.256832 139808827500288 ../../src/mcts_replace/search.cc:369] c3b1  (467 ) N:       1 (+ 1) (P:  0.00%) (Q: -0.93461) (U: -0.93461) (Q+U: -1.86921) (V:  -.----)
0323 22:50:48.256842 139808827500288 ../../src/mcts_replace/search.cc:369] c3b5  (489 ) N:       1 (+ 1) (P:  0.00%) (Q: -0.97848) (U: -0.97848) (Q+U: -1.95695) (V:  -.----)