Challenging test position

[brtzsnr]

Hi!

What does your engine say on this position from Bliep vs Zurichess https://ro.lichess.org/7luZXbPA#93

[d] 5bk1/5p2/7p/1Kp5/2P2B2/1Pqp3P/Q5P1/8 b - - 4 47


Zurichess sees Qc2 which loses the game. There is also a nasty explosion between depth 17 and 18 with very a large seldepth at depth 18.

Code: Select all

position fen 5bk1/5p2/7p/1Kp5/2P2B2/1Pqp3P/Q5P1/8 b - - 4 47
go
info depth 0 seldepth 0 multipv 1 score cp 71 nodes 2 time 0 nps 15790 pv
info depth 1 seldepth 1 multipv 1 score cp 122 nodes 78 time 0 nps 236862 pv c3e1
info depth 2 seldepth 2 multipv 1 score cp 139 nodes 504 time 1 nps 474660 pv c3c2 a2c2 d3c2
info depth 3 seldepth 3 multipv 1 score cp 139 nodes 992 time 1 nps 511580 pv c3c2 a2c2 d3c2
info depth 4 seldepth 4 multipv 1 score cp 119 nodes 1652 time 2 nps 552418 pv c3c2 a2c2 d3c2 g2g4
info depth 5 seldepth 5 multipv 1 score cp 154 nodes 2295 time 3 nps 614179 pv c3c2 a2c2 d3c2 g2g4 g8g7
info depth 6 seldepth 6 multipv 1 score cp 130 nodes 5718 time 10 nps 556591 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5
info depth 7 seldepth 7 multipv 1 score cp 152 nodes 9297 time 15 nps 611166 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5 f8e7
info depth 8 seldepth 8 multipv 1 score cp 147 nodes 14355 time 22 nps 636751 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5 g7g6 g2g4
info depth 9 seldepth 9 multipv 1 score cp 169 nodes 25364 time 34 nps 731017 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5 g7g6 g2g4 f8e7
info depth 10 seldepth 11 multipv 1 score cp 165 nodes 35117 time 45 nps 777029 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5 g7g6 f4e3 f8e7 e3f4
info depth 11 seldepth 11 multipv 1 score cp 169 nodes 49282 time 60 nps 815330 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5 g7g6 f4e3 f8e7 e3f4 e7g5
info depth 12 seldepth 12 multipv 1 score cp 174 nodes 77224 time 88 nps 875219 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5 g7g6 f4e3 f8e7 h3h4 h6h5 g2g3
info depth 13 seldepth 13 multipv 1 score cp 189 nodes 134684 time 138 nps 969028 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5 g7g6 f4e3 f8e7 e3f4 e7g5 f4g5 g6g5
info depth 14 seldepth 15 multipv 1 score cp 190 nodes 232536 time 209 nps 1109867 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5 g7g6 f4c1 f8e7 g2g3 e7g5 c1a3 g5e3 a3b2
info depth 15 seldepth 15 multipv 1 score cp 205 nodes 426368 time 346 nps 1232084 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5 g7g6 f4c1 f8e7 h3h4 h6h5 c1d2 g6f5 d2e3 f5g4
info depth 16 seldepth 17 multipv 1 score cp 220 nodes 780408 time 612 nps 1274681 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5 f8e7 f4c1 g7g6 g2g3 h6h5 h3h4 g6f5 c1d2 f5g4 d2f4
info depth 17 seldepth 19 multipv 1 score cp 221 nodes 2289241 time 1778 nps 1286825 pv c3c2 a2c2 d3c2 b5c6 g8g7 f4e3 g7g6 c6d5 h6h5 e3c1 g6f5 g2g3 f8e7 c1a3 e7f8 a3b2 f8g7
info depth 18 seldepth 27 multipv 1 score cp 114 nodes 123112705 time 632088 nps 194771 pv c3c2 a2c2 d3c2 f4d2 g8h7 b5a4 f8e7 a4a3 e7f6 d2c1 h7g6 b3b4 c5b4 a3b3 f6g5 c1g5 h6g5 b3c2 g6f5

[jdart]

Komodo and Stockish see that Qc2 is bad practically instantly.

--Jpn

[brtzsnr]

This position seems to be the problem. It doesn't see that the passed pawn is hanging and thus worhless.

[d] 6k1/5p2/8/4b2p/2P5/1K5P/2p3P1/2B5 b - - 1 53

[bob]

Hi!

What does your engine say on this position from Bliep vs Zurichess https://ro.lichess.org/7luZXbPA#93

[d] 5bk1/5p2/7p/1Kp5/2P2B2/1Pqp3P/Q5P1/8 b - - 4 47


Zurichess sees Qc2 which loses the game. There is also a nasty explosion between depth 17 and 18 with very a large seldepth at depth 18.

Code: Select all

position fen 5bk1/5p2/7p/1Kp5/2P2B2/1Pqp3P/Q5P1/8 b - - 4 47
go
info depth 0 seldepth 0 multipv 1 score cp 71 nodes 2 time 0 nps 15790 pv
info depth 1 seldepth 1 multipv 1 score cp 122 nodes 78 time 0 nps 236862 pv c3e1
info depth 2 seldepth 2 multipv 1 score cp 139 nodes 504 time 1 nps 474660 pv c3c2 a2c2 d3c2
info depth 3 seldepth 3 multipv 1 score cp 139 nodes 992 time 1 nps 511580 pv c3c2 a2c2 d3c2
info depth 4 seldepth 4 multipv 1 score cp 119 nodes 1652 time 2 nps 552418 pv c3c2 a2c2 d3c2 g2g4
info depth 5 seldepth 5 multipv 1 score cp 154 nodes 2295 time 3 nps 614179 pv c3c2 a2c2 d3c2 g2g4 g8g7
info depth 6 seldepth 6 multipv 1 score cp 130 nodes 5718 time 10 nps 556591 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5
info depth 7 seldepth 7 multipv 1 score cp 152 nodes 9297 time 15 nps 611166 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5 f8e7
info depth 8 seldepth 8 multipv 1 score cp 147 nodes 14355 time 22 nps 636751 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5 g7g6 g2g4
info depth 9 seldepth 9 multipv 1 score cp 169 nodes 25364 time 34 nps 731017 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5 g7g6 g2g4 f8e7
info depth 10 seldepth 11 multipv 1 score cp 165 nodes 35117 time 45 nps 777029 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5 g7g6 f4e3 f8e7 e3f4
info depth 11 seldepth 11 multipv 1 score cp 169 nodes 49282 time 60 nps 815330 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5 g7g6 f4e3 f8e7 e3f4 e7g5
info depth 12 seldepth 12 multipv 1 score cp 174 nodes 77224 time 88 nps 875219 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5 g7g6 f4e3 f8e7 h3h4 h6h5 g2g3
info depth 13 seldepth 13 multipv 1 score cp 189 nodes 134684 time 138 nps 969028 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5 g7g6 f4e3 f8e7 e3f4 e7g5 f4g5 g6g5
info depth 14 seldepth 15 multipv 1 score cp 190 nodes 232536 time 209 nps 1109867 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5 g7g6 f4c1 f8e7 g2g3 e7g5 c1a3 g5e3 a3b2
info depth 15 seldepth 15 multipv 1 score cp 205 nodes 426368 time 346 nps 1232084 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5 g7g6 f4c1 f8e7 h3h4 h6h5 c1d2 g6f5 d2e3 f5g4
info depth 16 seldepth 17 multipv 1 score cp 220 nodes 780408 time 612 nps 1274681 pv c3c2 a2c2 d3c2 b5c6 g8g7 c6d5 f8e7 f4c1 g7g6 g2g3 h6h5 h3h4 g6f5 c1d2 f5g4 d2f4
info depth 17 seldepth 19 multipv 1 score cp 221 nodes 2289241 time 1778 nps 1286825 pv c3c2 a2c2 d3c2 b5c6 g8g7 f4e3 g7g6 c6d5 h6h5 e3c1 g6f5 g2g3 f8e7 c1a3 e7f8 a3b2 f8g7
info depth 18 seldepth 27 multipv 1 score cp 114 nodes 123112705 time 632088 nps 194771 pv c3c2 a2c2 d3c2 f4d2 g8h7 b5a4 f8e7 a4a3 e7f6 d2c1 h7g6 b3b4 c5b4 a3b3 f6g5 c1g5 h6g5 b3c2 g6f5

I tried this on Crafty and it drops Qc2 after maybe 10ms. If I make it continue searching it, the score climbs to +1.5 for white very quickly. A normal search quickly switches to Qd4 with a -1.14 (good for black) eval...