37...Qe4 or Kf6 !?

[deeds]

I was reinforcing my EXP file (with games ending in an unexpected draw) and I came across this position :

FEN : 8/4b1pp/4k3/4pb2/1P6/1NP1Q3/1KPB2qP/8 b - - 6 37

I had several games where SF15.1 played as white and Eman 8.40 played as black.
At each game where Eman played 37...Qe4 (in order to exchange the queens with 38.Qxe4 Bxe4...), the game ended in a draw.


So i analyzed this position with SF16.1 to compare :

Code: Select all

Stockfish 16.1 by the Stockfish developers (see AUTHORS file)
position fen 8/4b1pp/4k3/4pb2/1P6/1NP1Q3/1KPB2qP/8 b - - 6 37
go infinite
info string NNUE evaluation using nn-baff1ede1f90.nnue
info string NNUE evaluation using nn-b1a57edbea57.nnue
info depth 39 seldepth 68 multipv 1 score cp -155 nodes  81551426 nps 287725 hashfull 1000 tbhits 0 time 283435 pv g2e4 e3e4 f5e4 b4b5 g7g5 c3c4 h7h5 d2e3 e4g2 c4c5 h5h4 c5c6 g5g4 e3g1 h4h3 c2c4 g4g3 h2g3 e7b4 c4c5 e6e7 g3g4 g2d5 g1h2 e5e4 b2c2 e4e3 c2d3 e3e2 d3e2 d5c4 e2f2 c4b3 h2d6 e7f7 f2g3 b3d5 g3h3 f7e6 g4g5 e6f5 h3h4 f5g6 h4g4 b4d2 c6c7 d5b7 d6f4 d2e1 f4e5 e1f2
info depth 40 seldepth 65 multipv 1 score cp -160 nodes 126960407 nps 259581 hashfull 1000 tbhits 0 time 489097 pv e6f6 b3a5 g2e4 e3e4 f5e4 c3c4 h7h5 c4c5 g7g5 c5c6 f6e6 b4b5 g5g4 d2e3 h5h4 b5b6 g4g3 h2g3 h4h3 e3g1 e7b4 b6b7 b4d6 g3g4 d6b8 b2c3 e4f3 g4g5 e5e4 a5b3 e6f7 b3d4 h3h2 g1h2 b8h2 c3c4 h2c7 c4b5 f3h5

SF16.1 said 37...Qe4 until D39 but suddently SF16.1 switched to 37...Kf6 at D40


After 37...Qe4 :

Code: Select all

Stockfish 16.1 by the Stockfish developers (see AUTHORS file)
position fen 8/4b1pp/4k3/4pb2/1P2q3/1NP1Q3/1KPB3P/8 w - - 7 38
go infinite
info string NNUE evaluation using nn-baff1ede1f90.nnue
info string NNUE evaluation using nn-b1a57edbea57.nnue
info depth 39 seldepth 59 multipv 1 score cp 126 nodes  84906412 nps 278288 hashfull 1000 tbhits 0 time 305102 pv e3e4 f5e4 c3c4 h7h5 b4b5 g7g5 d2e3 e4g2 c4c5 g5g4 c5c6 h5h4 c2c4 g4g3 h2g3 h4h3 e3g1 e7b4 c4c5 g2d5 g3g4 e6e7 g1h2 e5e4 b2c2 e4e3 c2d3 e3e2 d3e2 d5c4 e2f2 c4b3 h2d6 e7f7 f2g3 b3d5 g3h3 f7e6 h3h4 b4d2 g4g5 e6f5 c6c7 d2g5 h4g3 d5e6 b5b6 e6c8 c5c6
info depth 40 seldepth 60 multipv 1 score cp 144 nodes 103208676 nps 271603 hashfull 1000 tbhits 0 time 379997 pv e3e4 f5e4 c3c4 g7g5 b4b5 h7h5 d2e3 e4g2 c4c5 g5g4 c5c6 h5h4 c2c4 g4g3 h2g3 h4h3 e3g1 e7b4 c4c5 e6e7 g3g4 g2d5 g1h2 e5e4 b2c2 e4e3 c2d3 e3e2 d3e2 d5c4 e2f2 c4b3 h2d6 e7f7 f2g3 b3d5 g3h3 f7e8 g4g5 b4d2 h3g4 e8d8 g4f5 d2e3 f5g6 e3d2 g6f6 d2e3

SF16.1 said 38.e4 {+1.44/40}


After 37...Kf6 :

Code: Select all

Stockfish 16.1 by the Stockfish developers (see AUTHORS file)
position fen 8/4b1pp/5k2/4pb2/1P6/1NP1Q3/1KPB2qP/8 w - - 7 38
go infinite
info string NNUE evaluation using nn-baff1ede1f90.nnue
info string NNUE evaluation using nn-b1a57edbea57.nnue
info depth 39 seldepth 56 multipv 1 score cp 163 nodes  77177042 nps 219465 hashfull 1000 tbhits 0 time 351659 pv c3c4 f6g6 b4b5 g2h2 c4c5 h2g2 c5c6 h7h5 b3a5 e7d8 a5c4 g6h7 c4d6 g2d5 d6f5 d5b5 b2a3 b5c6 e3d3 d8f6 f5g3 g7g6 c2c4 f6e7 a3b3 h5h4 g3e4 h7g7 d2c3 c6e6 d3e3 g7f8 e4f2 g6g5 c3e5 e7f6 e3c5 f8f7 e5f6 e6f6
info depth 40 seldepth 67 multipv 1 score cp 184 nodes 114605982 nps 223793 hashfull 1000 tbhits 0 time 512106 pv c3c4 f6g6 b4b5 g2h2 c4c5 h2g2 c5c6 h7h5 b3a5 e7d8 a5c4 g6h7 c4d6 g2d5 d6f5 d5b5 b2a3 b5c6 e3d3 d8f6 f5g3 g7g6 c2c4 f6e7 a3b3 h5h4 g3e4 h7g7 d2c3 c6b6 b3c2 b6e6 d3d5 e6d5 c4d5 g6g5 c3e5 g7g6 e5c7 g5g4 c2d3 g4g3 d5d6 e7f8 d6d7 f8e7 d7d8q e7d8 c7d8 g6f7 d8h4 g3g2

SF16.1 said 38.c4 {+1.84/40}

[supernova]

I was reinforcing my EXP file (with games ending in an unexpected draw) and I came across this position :

FEN : 8/4b1pp/4k3/4pb2/1P6/1NP1Q3/1KPB2qP/8 b - - 6 37

I had several games where SF15.1 played as white and Eman 8.40 played as black.
At each game where Eman played 37...Qe4 (in order to exchange the queens with 38.Qxe4 Bxe4...), the game ended in a draw.


So i analyzed this position with SF16.1 to compare :

Code: Select all

Stockfish 16.1 by the Stockfish developers (see AUTHORS file)
position fen 8/4b1pp/4k3/4pb2/1P6/1NP1Q3/1KPB2qP/8 b - - 6 37
go infinite
info string NNUE evaluation using nn-baff1ede1f90.nnue
info string NNUE evaluation using nn-b1a57edbea57.nnue
info depth 39 seldepth 68 multipv 1 score cp -155 nodes  81551426 nps 287725 hashfull 1000 tbhits 0 time 283435 pv g2e4 e3e4 f5e4 b4b5 g7g5 c3c4 h7h5 d2e3 e4g2 c4c5 h5h4 c5c6 g5g4 e3g1 h4h3 c2c4 g4g3 h2g3 e7b4 c4c5 e6e7 g3g4 g2d5 g1h2 e5e4 b2c2 e4e3 c2d3 e3e2 d3e2 d5c4 e2f2 c4b3 h2d6 e7f7 f2g3 b3d5 g3h3 f7e6 g4g5 e6f5 h3h4 f5g6 h4g4 b4d2 c6c7 d5b7 d6f4 d2e1 f4e5 e1f2
info depth 40 seldepth 65 multipv 1 score cp -160 nodes 126960407 nps 259581 hashfull 1000 tbhits 0 time 489097 pv e6f6 b3a5 g2e4 e3e4 f5e4 c3c4 h7h5 c4c5 g7g5 c5c6 f6e6 b4b5 g5g4 d2e3 h5h4 b5b6 g4g3 h2g3 h4h3 e3g1 e7b4 b6b7 b4d6 g3g4 d6b8 b2c3 e4f3 g4g5 e5e4 a5b3 e6f7 b3d4 h3h2 g1h2 b8h2 c3c4 h2c7 c4b5 f3h5

SF16.1 said 37...Qe4 until D39 but suddently SF16.1 switched to 37...Kf6 at D40


After 37...Qe4 :

Code: Select all

Stockfish 16.1 by the Stockfish developers (see AUTHORS file)
position fen 8/4b1pp/4k3/4pb2/1P2q3/1NP1Q3/1KPB3P/8 w - - 7 38
go infinite
info string NNUE evaluation using nn-baff1ede1f90.nnue
info string NNUE evaluation using nn-b1a57edbea57.nnue
info depth 39 seldepth 59 multipv 1 score cp 126 nodes  84906412 nps 278288 hashfull 1000 tbhits 0 time 305102 pv e3e4 f5e4 c3c4 h7h5 b4b5 g7g5 d2e3 e4g2 c4c5 g5g4 c5c6 h5h4 c2c4 g4g3 h2g3 h4h3 e3g1 e7b4 c4c5 g2d5 g3g4 e6e7 g1h2 e5e4 b2c2 e4e3 c2d3 e3e2 d3e2 d5c4 e2f2 c4b3 h2d6 e7f7 f2g3 b3d5 g3h3 f7e6 h3h4 b4d2 g4g5 e6f5 c6c7 d2g5 h4g3 d5e6 b5b6 e6c8 c5c6
info depth 40 seldepth 60 multipv 1 score cp 144 nodes 103208676 nps 271603 hashfull 1000 tbhits 0 time 379997 pv e3e4 f5e4 c3c4 g7g5 b4b5 h7h5 d2e3 e4g2 c4c5 g5g4 c5c6 h5h4 c2c4 g4g3 h2g3 h4h3 e3g1 e7b4 c4c5 e6e7 g3g4 g2d5 g1h2 e5e4 b2c2 e4e3 c2d3 e3e2 d3e2 d5c4 e2f2 c4b3 h2d6 e7f7 f2g3 b3d5 g3h3 f7e8 g4g5 b4d2 h3g4 e8d8 g4f5 d2e3 f5g6 e3d2 g6f6 d2e3

SF16.1 said 38.e4 {+1.44/40}


After 37...Kf6 :

Code: Select all

Stockfish 16.1 by the Stockfish developers (see AUTHORS file)
position fen 8/4b1pp/5k2/4pb2/1P6/1NP1Q3/1KPB2qP/8 w - - 7 38
go infinite
info string NNUE evaluation using nn-baff1ede1f90.nnue
info string NNUE evaluation using nn-b1a57edbea57.nnue
info depth 39 seldepth 56 multipv 1 score cp 163 nodes  77177042 nps 219465 hashfull 1000 tbhits 0 time 351659 pv c3c4 f6g6 b4b5 g2h2 c4c5 h2g2 c5c6 h7h5 b3a5 e7d8 a5c4 g6h7 c4d6 g2d5 d6f5 d5b5 b2a3 b5c6 e3d3 d8f6 f5g3 g7g6 c2c4 f6e7 a3b3 h5h4 g3e4 h7g7 d2c3 c6e6 d3e3 g7f8 e4f2 g6g5 c3e5 e7f6 e3c5 f8f7 e5f6 e6f6
info depth 40 seldepth 67 multipv 1 score cp 184 nodes 114605982 nps 223793 hashfull 1000 tbhits 0 time 512106 pv c3c4 f6g6 b4b5 g2h2 c4c5 h2g2 c5c6 h7h5 b3a5 e7d8 a5c4 g6h7 c4d6 g2d5 d6f5 d5b5 b2a3 b5c6 e3d3 d8f6 f5g3 g7g6 c2c4 f6e7 a3b3 h5h4 g3e4 h7g7 d2c3 c6b6 b3c2 b6e6 d3d5 e6d5 c4d5 g6g5 c3e5 g7g6 e5c7 g5g4 c2d3 g4g3 d5d6 e7f8 d6d7 f8e7 d7d8q e7d8 c7d8 g6f7 d8h4 g3g2

SF16.1 said 38.c4 {+1.84/40}

I am not sure why you use such an old version of Stockfish as well as a discontinued engine like Eman. I would use Brainlearn instead.

The analysis shows that Qe4 is the way to go:

[botunnet]

FEN : 8/4b1pp/4k3/4pb2/1P6/1NP1Q3/1KPB2qP/8 b - - 6 37


So i analyzed this position with SF16.1 to compare :

Code: Select all

...
info depth 39 seldepth 68 multipv 1 score cp -155 nodes  81551426 nps 287725 hashfull 1000 tbhits 0 time 283435 pv g2e4 e3e4 f5e4 b4b5 g7g5 c3c4 h7h5 d2e3 e4g2 c4c5 h5h4 c5c6 g5g4 e3g1 h4h3 c2c4 g4g3 h2g3 e7b4 c4c5 e6e7 g3g4 g2d5 g1h2 e5e4 b2c2 e4e3 c2d3 e3e2 d3e2 d5c4 e2f2 c4b3 h2d6 e7f7 f2g3 b3d5 g3h3 f7e6 g4g5 e6f5 h3h4 f5g6 h4g4 b4d2 c6c7 d5b7 d6f4 d2e1 f4e5 e1f2
...
info depth 40 seldepth 65 multipv 1 score cp -160 nodes 126960407 nps 259581 hashfull 1000 tbhits 0 time 489097 pv e6f6 b3a5 g2e4 e3e4 f5e4 c3c4 h7h5 c4c5 g7g5 c5c6 f6e6 b4b5 g5g4 d2e3 h5h4 b5b6 g4g3 h2g3 h4h3 e3g1 e7b4 b6b7 b4d6 g3g4 d6b8 b2c3 e4f3 g4g5 e5e4 a5b3 e6f7 b3d4 h3h2 g1h2 b8h2 c3c4 h2c7 c4b5 f3h5
...

SF16.1 said 37...Qe4 until D39 but suddently SF16.1 switched to 37...Kf6 at D40
...

Dragon 3.3 even thinked about Kf7

Code: Select all

...
info depth 34 time  758605 nodes 216957660 score cp -175 nps 285995 hashfull 1000 tbhits 0 pv g2e4 e3e4 f5e4 b4b5 h7h5 d2e3 g7g5 c3c4 e4f3 c4c5 g5g4 c5c6 h5h4 b3c5 e6d6 c2c4 g4g3 h2h3 f3g2 c5a6 g2h3 e3c5 d6e6 b5b6 e7c5 a6c5 e6f7 c6c7 g3g2 b6b7 g2g1q c7c8q g1d4 b2b3 h3c8 b7c8q h4h3 c8f5 f7g8 f5g6 g8h8 g6f6 h8g8 c5e6 d4d1 b3b4 d1d2 b4c5 d2a5 c5d6 a5a6 d6e5 a6a1 e6d4 a1a5 e5e4
info depth 35 time  943374 nodes 267648750 score cp -196 nps 283714 hashfull 1000 tbhits 0 pv e6f6 c3c4 f6g6 c4c5 g2h2 b4b5 h2g2 c5c6 g2d5 e3a7 e7d6 a7a4 e5e4 b5b6 d6e5 b2a3 h7h5 c6c7 g6f7 c2c4 d5d6 c4c5 d6d5 d2c1 e4e3 c1e3 f5d7 a4a6 d7e6 a6f1 f7e7 f1b5 d5e4 b6b7 e5c7 b7b8q c7b8 e3g5 e7f7 b5b8 h5h4 b8f4 e4f4 g5f4
info depth 37 time 1215849 nodes 354119872 score cp -199 nps 291252 hashfull 1000 tbhits 0 pv e6f7 e3e5 g2e4 e5e4 f5e4 d2f4 g7g5 f4b8 h7h5 b4b5 f7e6 c3c4 h5h4 c4c5 e7f6 c2c3 e6d5 c5c6 g5g4 b3a5 d5c5 a5b7 c5b6 b7d6 e4d5 b2c2 d5e6 c6c7 g4g3 h2g3 h4h3 g3g4 e6g4 c2d3 f6c3 c7c8q g4c8 d6c8 b6b5 d3c3 h3h2 b8h2 b5c6 c3b4 c6b7 c8d6 b7a8 b4b5
info depth 38 time 1717529 nodes 521382042 score cp -205 nps 303565 hashfull 1000 tbhits 0 pv e6f6 b3a5 h7h6 b4b5 g2f1 c3c4 f1d1 e3c3 f6f7 c4c5 e7f6 a5b3 e5e4 b3d4 f5e6 b5b6 e6d5 c3b4 e4e3 d2e3 d1e2 e3d2 e2e4 d2c3 f6d4 c3d4 g7g5 b4a4 f7e7 b2a3 d5b7 a4c4 b7d5 c4d3 e7d7 d3b5 d7e7 c2c3 d5b7 b5c4 b7d5 c4a4 d5c6

[deeds]

Dragon 3.3 even thinked about Kf7

Code: Select all

...
info depth 34 time  758605 nodes 216957660 score cp -175 nps 285995 hashfull 1000 tbhits 0 pv g2e4 e3e4 f5e4 b4b5 h7h5 d2e3 g7g5 c3c4 e4f3 c4c5 g5g4 c5c6 h5h4 b3c5 e6d6 c2c4 g4g3 h2h3 f3g2 c5a6 g2h3 e3c5 d6e6 b5b6 e7c5 a6c5 e6f7 c6c7 g3g2 b6b7 g2g1q c7c8q g1d4 b2b3 h3c8 b7c8q h4h3 c8f5 f7g8 f5g6 g8h8 g6f6 h8g8 c5e6 d4d1 b3b4 d1d2 b4c5 d2a5 c5d6 a5a6 d6e5 a6a1 e6d4 a1a5 e5e4
info depth 35 time  943374 nodes 267648750 score cp -196 nps 283714 hashfull 1000 tbhits 0 pv e6f6 c3c4 f6g6 c4c5 g2h2 b4b5 h2g2 c5c6 g2d5 e3a7 e7d6 a7a4 e5e4 b5b6 d6e5 b2a3 h7h5 c6c7 g6f7 c2c4 d5d6 c4c5 d6d5 d2c1 e4e3 c1e3 f5d7 a4a6 d7e6 a6f1 f7e7 f1b5 d5e4 b6b7 e5c7 b7b8q c7b8 e3g5 e7f7 b5b8 h5h4 b8f4 e4f4 g5f4
info depth 37 time 1215849 nodes 354119872 score cp -199 nps 291252 hashfull 1000 tbhits 0 pv e6f7 e3e5 g2e4 e5e4 f5e4 d2f4 g7g5 f4b8 h7h5 b4b5 f7e6 c3c4 h5h4 c4c5 e7f6 c2c3 e6d5 c5c6 g5g4 b3a5 d5c5 a5b7 c5b6 b7d6 e4d5 b2c2 d5e6 c6c7 g4g3 h2g3 h4h3 g3g4 e6g4 c2d3 f6c3 c7c8q g4c8 d6c8 b6b5 d3c3 h3h2 b8h2 b5c6 c3b4 c6b7 c8d6 b7a8 b4b5
info depth 38 time 1717529 nodes 521382042 score cp -205 nps 303565 hashfull 1000 tbhits 0 pv e6f6 b3a5 h7h6 b4b5 g2f1 c3c4 f1d1 e3c3 f6f7 c4c5 e7f6 a5b3 e5e4 b3d4 f5e6 b5b6 e6d5 c3b4 e4e3 d2e3 d1e2 e3d2 e2e4 d2c3 f6d4 c3d4 g7g5 b4a4 f7e7 b2a3 d5b7 a4c4 b7d5 c4d3 e7d7 d3b5 d7e7 c2c3 d5b7 b5c4 b7d5 c4a4 d5c6

Use Regular Eval = false ?

[botunnet]

Dragon 3.3 even thinked about Kf7

Code: Select all

...
info depth 34 time  758605 nodes 216957660 score cp -175 nps 285995 hashfull 1000 tbhits 0 pv g2e4 e3e4 f5e4 b4b5 h7h5 d2e3 g7g5 c3c4 e4f3 c4c5 g5g4 c5c6 h5h4 b3c5 e6d6 c2c4 g4g3 h2h3 f3g2 c5a6 g2h3 e3c5 d6e6 b5b6 e7c5 a6c5 e6f7 c6c7 g3g2 b6b7 g2g1q c7c8q g1d4 b2b3 h3c8 b7c8q h4h3 c8f5 f7g8 f5g6 g8h8 g6f6 h8g8 c5e6 d4d1 b3b4 d1d2 b4c5 d2a5 c5d6 a5a6 d6e5 a6a1 e6d4 a1a5 e5e4
info depth 35 time  943374 nodes 267648750 score cp -196 nps 283714 hashfull 1000 tbhits 0 pv e6f6 c3c4 f6g6 c4c5 g2h2 b4b5 h2g2 c5c6 g2d5 e3a7 e7d6 a7a4 e5e4 b5b6 d6e5 b2a3 h7h5 c6c7 g6f7 c2c4 d5d6 c4c5 d6d5 d2c1 e4e3 c1e3 f5d7 a4a6 d7e6 a6f1 f7e7 f1b5 d5e4 b6b7 e5c7 b7b8q c7b8 e3g5 e7f7 b5b8 h5h4 b8f4 e4f4 g5f4
info depth 37 time 1215849 nodes 354119872 score cp -199 nps 291252 hashfull 1000 tbhits 0 pv e6f7 e3e5 g2e4 e5e4 f5e4 d2f4 g7g5 f4b8 h7h5 b4b5 f7e6 c3c4 h5h4 c4c5 e7f6 c2c3 e6d5 c5c6 g5g4 b3a5 d5c5 a5b7 c5b6 b7d6 e4d5 b2c2 d5e6 c6c7 g4g3 h2g3 h4h3 g3g4 e6g4 c2d3 f6c3 c7c8q g4c8 d6c8 b6b5 d3c3 h3h2 b8h2 b5c6 c3b4 c6b7 c8d6 b7a8 b4b5
info depth 38 time 1717529 nodes 521382042 score cp -205 nps 303565 hashfull 1000 tbhits 0 pv e6f6 b3a5 h7h6 b4b5 g2f1 c3c4 f1d1 e3c3 f6f7 c4c5 e7f6 a5b3 e5e4 b3d4 f5e6 b5b6 e6d5 c3b4 e4e3 d2e3 d1e2 e3d2 e2e4 d2c3 f6d4 c3d4 g7g5 b4a4 f7e7 b2a3 d5b7 a4c4 b7d5 c4d3 e7d7 d3b5 d7e7 c2c3 d5b7 b5c4 b7d5 c4a4 d5c6

Use Regular Eval = false ?

Yes, i used the default settings.

But with "Use Regular Eval" set to true, they are the same main moves :

Code: Select all

setoption name Use Regular Eval value true
position fen 8/4b1pp/4k3/4pb2/1P6/1NP1Q3/1KPB2qP/8 b - - 6 37
go depth 40
info depth 37 time  58335 nodes 2158267163 score cp -151 nps 36997368 hashfull 1000 tbhits 0 pv g2e4 e3e4 f5e4 b4b5 h7h5 c3c4 g7g5 c4c5 g5g4 c5c6 h5h4 d2e3 e4f3 e3g1 e7d6 c2c4 e6e7 c4c5 d6b8 b3a5 e5e4 b5b6 g4g3 c6c7 b8c7 b6c7 e7d7 h2g3 h4g3 b2c3 f3e2 c3d4 e2d3 c7c8q d7c8 a5c4 c8c7 c4d6 g3g2 d4e3 c7c6 d6e4 d3c2 e3f3

info depth 37 time 124478 nodes 4387961246 score cp -150 nps 35250647 hashfull 1000 tbhits 0 pv e6f6 c3c4 f6g6 c4c5 g2h2 b4b5 h2g2 c5c6 h7h5 e3a7 e7d6 c6c7 g6h7 a7b6 g2d5 b6f2 d5e4 d2a5 e4f4 f2b6 e5e4 b6c6 e4e3 b5b6 e3e2 a5e1 d6e5 b2a2 f5c8 c6e8 f4f5 a2b1 c8a6 e8a4 a6b7 a4a5 b7c8 a5d5 g7g5 b6b7 e5c7 b7c8q f5c8 d5g5
info depth 38 time 161817 nodes 5615154979 score cp -149 nps 34700554 hashfull 1000 tbhits 0 pv e6f6 c3c4 f6g6 b4b5 g2h2 c4c5 h2g2 c5c6 h7h5 e3a7 e7d6 c6c7 g2e4 c7c8q f5c8 a7b6 e4d5 d2b4 c8d7 b4d6 d5b5 b6e3 g6f6 e3f3 f6g6 f3g3 g6f6 g3h4 f6g6 h4e7 d7g4 d6e5 b5d7 e7b4 d7f5 b4d6 g6h7 d6e7 f5g6 b3d4 g6h6 e7b7 h6g5 b7e4 g5g6 e4g6 h7g6 c2c4 g6f7 b2c3 g4c8 c4c5
info depth 39 time 179148 nodes 6186141710 score cp -153 nps 34530818 hashfull 1000 tbhits 0 pv e6f6 c3c4 f6g6 c4c5 g2h2 b4b5 h7h5 c5c6 h2g2 e3a7 e7d6 c6c7 g2e4 c7c8q f5c8 a7b6 e4d5 d2b4 c8d7 b4d6 d5b5 b6e3 b5c4 e3e5 c4b5 e5e4 d7f5 e4f4 b5b7 d6e5 b7e4 f4g3 f5g4 g3c3 e4b7 c3d4 g4e6 d4g1 g6h6 g1e3 h6g6 e3g3 e6g4 g3f4 g4e6 f4h4 e6g4 h4f2 b7f7 f2d4 g4e6 b3c5 e6f5
info depth 40 time 213401 nodes 7312310457 score cp -145 nps 34265427 hashfull 1000 tbhits 0 pv e6f6 c3c4 f6g6 c4c5 g2h2 b4b5 h2g2 c5c6 h7h5 e3a7 e7d6 c6c7 g2e4 c7c8q f5c8 a7b6 e4d5 d2b4 c8d7 b4d6 d5b5 b6e3 g6f6 e3f3 f6g6 f3g3 g6f6 g3h4 f6g6 h4e7 d7g4 d6e5 b5d7 e7b4 d7f7 b4d4 g4e6 b3c5 e6f5 c2c4 f7a7 c5b3 a7d4 b3d4 f5e4 c4c5 g6f7 b2c3 g7g5 c3d2 h5h4 d2e3 e4d5 c5c6 f7e7 d4f5 e7e6
bestmove e6f6 ponder c3c4

[supernova]

Dragon 3.3 even thinked about Kf7

What is the goal of using an old engine instead of the last Version of Stockfish? Question still opened and unanswered.