Does any engine consider this move?

[glav]

In this interesting video, GM Sadler explains how, by lowering the Leela WDL (Win Draw Loss) contempt value, he finds the interesting move 5) g4!? to be used as a practical attempt in a human tournament game. I liked the idea, but since I do not posses a GPU, I was trying to use Stockfish to see if I could spot this move, but I couldn't, even as third or foruth choice. I even tried the very aggressive Patricia program, but even this software that has otherwise played some very spectacular moves, doesn't consider to play it at all. Does anyone know I could tweak engine parameters in order to have them to consider this move as reasonable?
[d]rnbqkb1r/pp3ppp/2p1pn2/3p4/2PP2P1/2N2N2/PP2PP1P/R1BQKB1R b KQkq - 0 5

]

[peter]

Out of chessbase online database to the 15 rated games stored there:



In Herbert Bellmann's corr. database 2025, I found this one game only:

[pgn][Event "corr FICGS CHESS 2023"]
[Site "FICGS"]
[Date "2023.11.17"]
[Round "2"]
[White "Ambos, Ilmar"]
[Black "Armstrong, Keith"]
[Result "1/2-1/2"]
[ECO "D43"]
[WhiteElo "2249"]
[BlackElo "2314"]
[PlyCount "87"]
[GameId "2090837457207567"]
[EventDate "2023.??.??"]
[EventType "tourn (corr)"]
[SourceTitle "Fernschach2025"]
[SourceDate "2024.10.15"]
[SourceVersion "1"]
[SourceVersionDate "2024.10.15"]
[SourceQuality "1"]

1. Nf3 d5 2. d4 Nf6 3. c4 e6 4. Nc3 c6 5. g4 Nxg4 6. Rg1 Nf6 7. Qd3 b5 8. cxd5 cxd5 9. Nxb5 Nc6 10. Bf4 Bb4+ 11. Nc3 Nh5 12. Bd2 O-O 13. e4 Bd7 14. a3 Bxc3 15. Bxc3 Nf6 16. Nd2 dxe4 17. Nxe4 Nd5 18. Qg3 g6 19. Bc4 Nce7 20. Qh4 Kg7 21. Bxd5 Nxd5 22. Qxd8 Rfxd8 23. Ba5 Rdb8 24. Nc5 Be8 25. b3 Ne7 26. Rc1 Rc8 27. Bc3 Kf8 28. f3 Nf5 29. Kf2 Bc6 30. a4 a5 31. d5 exd5 32. Bf6 h6 33. Rge1 Rcb8 34. Be5 Rb4 35. Bc3 Rbb8 36. Bf6 Ra7 37. Re5 d4 38. h4 Re8 39. Rxe8+ Kxe8 40. h5 Ra8 41. hxg6 fxg6 42. Ne6 Kd7 43. Nxd4 Nxd4 44. Bxd4 1/2-1/2
[/pgn]

[glav]

Out of chessbase online database to the 15 rated games stored there:



In Herbert Bellmann's corr. database 2025, I found this one game only:

[pgn][Event "corr FICGS CHESS 2023"]
[Site "FICGS"]
[Date "2023.11.17"]
[Round "2"]
[White "Ambos, Ilmar"]
[Black "Armstrong, Keith"]
[Result "1/2-1/2"]
[ECO "D43"]
[WhiteElo "2249"]
[BlackElo "2314"]
[PlyCount "87"]
[GameId "2090837457207567"]
[EventDate "2023.??.??"]
[EventType "tourn (corr)"]
[SourceTitle "Fernschach2025"]
[SourceDate "2024.10.15"]
[SourceVersion "1"]
[SourceVersionDate "2024.10.15"]
[SourceQuality "1"]

1. Nf3 d5 2. d4 Nf6 3. c4 e6 4. Nc3 c6 5. g4 Nxg4 6. Rg1 Nf6 7. Qd3 b5 8. cxd5 cxd5 9. Nxb5 Nc6 10. Bf4 Bb4+ 11. Nc3 Nh5 12. Bd2 O-O 13. e4 Bd7 14. a3 Bxc3 15. Bxc3 Nf6 16. Nd2 dxe4 17. Nxe4 Nd5 18. Qg3 g6 19. Bc4 Nce7 20. Qh4 Kg7 21. Bxd5 Nxd5 22. Qxd8 Rfxd8 23. Ba5 Rdb8 24. Nc5 Be8 25. b3 Ne7 26. Rc1 Rc8 27. Bc3 Kf8 28. f3 Nf5 29. Kf2 Bc6 30. a4 a5 31. d5 exd5 32. Bf6 h6 33. Rge1 Rcb8 34. Be5 Rb4 35. Bc3 Rbb8 36. Bf6 Ra7 37. Re5 d4 38. h4 Re8 39. Rxe8+ Kxe8 40. h5 Ra8 41. hxg6 fxg6 42. Ne6 Kd7 43. Nxd4 Nxd4 44. Bxd4 1/2-1/2
[/pgn]

Thanks Peter, but, as I said, I am more interested in seeing if any engine, besides Leela, finds this move interesting. Also Matthew Sadler mentions in the videa that this is a rar move in database, excapert for the lichess one where everything goes.

[peter]

I am more interested in seeing if any engine, besides Leela, finds this move interesting.

Well Lc0 doesn't find the move very interesting at first glance neither at my trial, and I don't know, why any engine with reasonable settings (didn't try much with aggressive Dragon or anything like that) should do so, if 5.Bg5 and 5.e3 for sure are to be pondered about much more, aren't they?

Here's Lc0 dev. with net 6147500PT and 3070ti GPU:

rnbqkb1r/pp3ppp/2p1pn2/3p4/2PP4/2N2N2/PP2PPPP/R1BQKB1R w KQkq - 0 1

Analysis by Lc0 v0.32.0-dev+git.63b66e4:

Code: Select all

5.Lg5 h6 
  Die Stellung ist ausgeglichen.  
  = (0.16)  Tiefe: 1/2   00:00:08  2Knoten
...
5.e3 Ld6 6.Ld3 
  Die Stellung ist ausgeglichen.  
  = (0.17)  Tiefe: 2/3   00:00:08  6Knoten
...
5.e3 Ld6 6.Dc2 Sbd7 7.Ld3 0-0 8.0-0 dxc4 9.Lxc4 a6 10.e4 e5 11.h3 b5 12.Lb3 c5 13.dxc5 Sxc5 14.Td1 Sxb3 15.axb3 Lb7 16.Lg5 h6 17.Lh4 Te8 18.De2 Te6 19.Sd5 Lxd5 
  Die Stellung ist ausgeglichen.  
  = (0.18)  Tiefe: 16/57   00:02:32  901kN

Here with MultiPV=2 in depth 19:

rnbqkb1r/pp3ppp/2p1pn2/3p4/2PP4/2N2N2/PP2PPPP/R1BQKB1R w KQkq - 0 1

Analysis by Lc0 v0.32.0-dev+git.63b66e4:

1. = (0.18): 5.e3 Ld6 6.Dc2 Sbd7 7.Ld3 0-0 8.0-0 e5 9.cxd5 cxd5 10.e4 dxe4 11.Sxe4 Sxe4 12.Lxe4 h6 13.Le3 exd4 14.Lh7+ Kh8 15.Lxd4 Sf6 16.Lf5 Da5 17.Lxc8 Tfxc8 18.Db3 Dd5 19.Dd1 Df5 20.Te1 Td8 21.Db3 Dd5 22.Da4 Df5 23.Tad1 b6 24.Db3 Kg8 25.Sh4 Dg5 26.g3 Lc5 27.Sf3 Df5 28.Te5
2. = (0.13): 5.Lg5 h6 6.Lxf6 Dxf6 7.e3 g6 8.Se5 Lg7 9.f4 0-0 10.h4 De7 11.Df3 Sd7 12.Ld3 Sxe5 13.dxe5 Ld7 14.Dg3 h5 15.Dg5 Dc5 16.Ke2 Le8 17.Tac1 f6 18.exf6

And to get 5.g4 into MultiPV- output and keep it there I had to set it to =18, here in depth 20:

Code: Select all

rnbqkb1r/pp3ppp/2p1pn2/3p4/2PP4/2N2N2/PP2PPPP/R1BQKB1R w KQkq - 0 1

Analysis by Lc0 v0.32.0-dev+git.63b66e4:

1. = (0.17):  5.e3 Ld6 6.Dc2 Sbd7 7.Ld3 h6 8.0-0 0-0 9.b3 e5 10.cxd5 Sxd5 11.Sxd5 cxd5 12.Sxe5 Sxe5 13.dxe5 Lxe5 14.Lb2 Df6 15.Lxe5 Dxe5 16.Tac1 Ld7 17.Dc5 Tfc8 18.Da5 Txc1 19.Txc1 Db2 20.Td1 Le6 21.h3 g6 22.Tb1 De5
2. = (0.14):  5.Lg5 h6 6.Lxf6 Dxf6 7.e3 g6 8.Le2 Lg7 9.e4 dxe4 10.Sxe4 Df4 11.Dc2 c5 12.dxc5 0-0 13.Td1 a5 14.0-0 Ld7 15.g3 Dc7 16.Sd4 Lc6 17.Lf3 Lxe4 18.Dxe4 Dxc5 19.Sb3 Db4 20.Dxb7 Dxb7 21.Lxb7 Ta7 22.Sc5 Lf6 23.Lg2 Tc7
3. = (0.06):  5.Ld2 dxc4 6.a4 c5 7.e3 cxd4 8.exd4 Lb4 9.Lxc4 Sc6 10.Lg5 h6 11.Lh4 0-0 12.0-0 Le7 13.Te1 b6 14.Lxf6 Lxf6 15.d5 Sa5 16.La2 Lxc3 17.bxc3 exd5 18.Dd3
4. = (0.04):  5.g3 dxc4 6.Se5 b5 7.Lg2 a6 8.0-0 Lb7 9.b3 b4 10.Sa4 c3 11.a3 a5 12.Dc2 Sbd7 13.Td1 Sxe5 14.dxe5 Sd7 15.Le3 Dc7 16.Txd7 Dxd7 17.Sb6 Dc7 18.axb4 Lxb4 19.Sxa8 Lxa8 20.Ld4 c5 21.Lxc3 Lxg2 22.Lxb4 axb4 23.Kxg2 0-0 24.De4 Td8 25.Tc1 Db6 26.Dc4 Td5 27.e4
5. = (0.04):  5.cxd5 exd5 6.Lf4 Lf5 7.e3 Sbd7 8.h3 Db6 9.Ld3 Lxd3 10.Dxd3 Le7 11.Dc2 0-0 12.0-0 Tfe8 13.Tab1 a5 14.a3
6. = (0.04):  5.a4 a5 6.Lf4 Ld6 7.Lg3 Sa6 8.e3 Sb4 9.Se5 b6 10.Le2 0-0 11.0-0 Se4
7. = (0.02):  5.Dd3 dxc4 6.Dxc4 a6 7.g4 b5 8.Dd3 Sxg4 9.Tg1 Sf6 10.e4 Lb7 11.Le3 g6 12.e5 Sd5 13.Sxd5 cxd5 14.Le2 Sc6 15.h4 h6 16.h5 gxh5 17.Kf1 Kd7 18.Se1 h4
8. = (0.02):  5.Db3 dxc4 6.Dxc4 a6 7.g4 b5 8.Dd3 Sxg4 9.Tg1 Sf6 10.e4 Lb7 11.Le3 g6 12.e5 Sd5 13.Sxd5 cxd5 14.Le2 Sc6 15.h4 h6 16.h5 gxh5 17.Kf1 Kd7 18.Se1
9. = (0.02):  5.Se5 Sfd7 6.Sxd7 Sxd7 7.e3 Ld6 8.e4 0-0 9.e5 Lc7 10.f4 f6 11.cxd5 cxd5 12.Dh5 Lb6 13.Le3 fxe5 14.fxe5
10. = (0.01):  5.Da4 Sbd7 6.cxd5 Sb6 7.Dc2 exd5 8.Lg5 g6 9.e3 Lf5 10.Ld3 Lxd3 11.Dxd3 Le7 12.Lh6 Lf8 13.Lg5
11. = (-0.05):  5.Dc2 dxc4 6.a4 Ld7 7.e3 b5 8.Se5 Sd5 9.Le2 Le7 10.0-0 0-0 11.b3 cxb3 12.Dxb3 b4 13.Se4 a5 14.Lb2 Le8 15.Tac1 f6 16.Sd3 Lf7 17.Sec5 Sd7
12. = (-0.10):  5.Sd2 c5 6.e3 Sc6 7.Sf3 cxd4 8.exd4 Lb4 9.cxd5 exd5 10.Ld3 Lg4 11.0-0 0-0 12.Lg5 Le7 13.Le3 Te8 14.h3 Lh5 15.g4 Lg6 16.Se5
13. = (-0.22):  5.h4 dxc4 6.e4 b5 7.Le2 Lb7 8.0-0 Le7 9.b3 b4 10.e5 bxc3 11.exf6 Lxf6 12.Lg5 c5 13.dxc5 Dxd1 14.Tfxd1 c2 15.Td2 cxb3 16.Lxf6 gxf6
14. = (-0.24):  5.c5 b6 6.cxb6 axb6 7.e3 Ld6 8.Ld3 Sbd7 9.0-0 Lb7 10.Te1 0-0 11.e4 dxe4
15. = (-0.27):  5.Lf4 dxc4 6.a4 Lb4 7.g3 a5 8.Lg2 0-0 9.0-0 Sbd7 10.Dc2 Sd5 11.Ld2 Le7 12.Se4 h6 13.Dxc4 b6 14.Dxc6 La6
16. = (-0.27):  5.a3 dxc4 6.e4 b5 7.Le2 a6 8.0-0 Lb7 9.b3 cxb3 10.Dxb3 Le7 11.Td1 0-0 12.e5 Sd5 13.Sxd5 Dxd5 14.Dc2 c5 15.Lg5 Lxg5 16.dxc5 De4 17.Dxe4 Lxe4 18.Sxg5
17. = (-0.29):  5.h3 dxc4 6.e4 b5 7.Le2 Lb7 8.0-0 Le7 9.b3 b4 10.e5 bxc3 11.exf6 Lxf6 12.La3 c5 13.Lxc5 Sa6 14.La3 Da5 15.Dc1 Lxf3 16.Lxf3 0-0-0 17.bxc4 Txd4 18.Tb1 Txc4 19.Le2 Tc6 20.Tb5 Da4 21.Tb3 Sc7
18. =/+ (-0.32):  5.g4 Sxg4 6.Lf4 dxc4 7.e3 b5 8.a4 Sf6 9.axb5 cxb5 10.Sxb5 Lb4+ 11.Sd2 0-0 12.Tg1 Lb7 13.Lh6 Se8 14.Dg4 f5

And after giving in 5.g4(?!):

rnbqkb1r/pp3ppp/2p1pn2/3p4/2PP2P1/2N2N2/PP2PP1P/R1BQKB1R b KQkq - 0 1

Analysis by Lc0 v0.32.0-dev+git.63b66e4:

5...Sxg4 6.Lf4 dxc4 7.e3 b5 8.a4 Sf6 9.axb5 cxb5 10.Sxb5 Lb4+ 11.Sd2 0-0 12.Tg1 Lb7 13.Lh6 Se8 14.Dg4 f5 15.Dxg7+
Schwarz steht etwas besser.
=/+ (-0.38) Tiefe: 11/18 00:00:00
...
5...Sxg4 6.e4 dxe4 7.Sxe4 e5 8.c5 Sf6 9.De2 Sxe4 10.Dxe4 Le6 11.Sxe5 Sd7 12.Lc4 Sf6 13.Dd3 Sd5 14.Ld2 f6 15.Sf3 Dd7 16.0-0-0 g6 17.a4 0-0-0 18.b4 Sc7 19.Lxe6 Sxe6 20.The1 Lg7 21.b5 Dd5 22.bxc6 Dxc6 23.Db5 The8 24.Dxc6+ bxc6 25.Te2 Td5 26.Tde1 Kd7 27.Lc3 Tf5 28.Sd2
Schwarz hat minimalen Vorteil.
= (-0.27) Tiefe: 21/62 00:02:09 451kN

Of course it can be played to surprise an opponent thus, you just give away White's advantage that should be as big as it is at very starting position, shouldn't it?

[glav]

I am more interested in seeing if any engine, besides Leela, finds this move interesting.

Of course it can be played to surprise an opponent thus, you just give away White's advantage that should be as big as it is at very starting position, shouldn't it?

Thanks Peter. This was the point of my whole post. In the video I posted, Mathhew Sadler tweaks the WDS value in order to let Leela agree that this is a reasonable move. I was wondering if there was a similar way to trick other engines to play it as well.

[Damir]

g4 move was first played by Zappa chess engine, back in the Anthony Cozzie days in WCCC 2005.

Here is the game.

[pgn][Event "WCCC 2005"]
[Site "Reykjavík, Iceland"]
[Date "2005.08.19"]
[Round "7"]
[White "Zappa"]
[Black "Junior"]
[Result "1-0"]

1.d4 d5 2.Nf3 Nf6 3.c4 e6 4.Nc3 c6 5.e3 Nbd7 6.Qc2 Bd6 7.g4 h6
8.Rg1 e5 9.cxd5 cxd5 10.g5 hxg5 11.Nxg5 e4 12.Nb5 Nb6 13.Bd2 Bf5
14.h3 Bh2 15.Rg2 Rc8 16.Qb3 Bb8 17.Bb4 Nh7 18.Nxh7 Rxh7 19.Rg1 Rc6
20.Nc3 a6 21.a4 Nc4 22.Bxc4 dxc4 23.Qc2 Rch6 24.Qe2 Qc8 25.O-O-O b5
26.d5 Qb7 27.d6 Bd7 28.axb5 axb5 29.Rg5 f5 30.Rd5 Qa8 31.Kb1 g6
32.Re5+ Kf7 33.Nd5 Kf8 34.Nf6 Rf7 35.Re8+ Kg7 36.Nh5+ Kh7 1-0[/pgn]

[Damir]

[pgn][Event "WCCC 2005"]
[Site "Reykjavik"]
[Date "2005.08.20"]
[Round "10"]
[White "Zappa 2.0b x64"]
[Black "Crafty"]
[Result "1-0"]
[ECO "D45"]

{800MB, zappa.ctg, VEL5933} 1. d4 {[%emt 0:00:00]} d5 {[%emt 0:00:15]} 2. Nf3 {
[%emt 0:00:00]} Nf6 {[%emt 0:00:17]} 3. c4 {[%emt 0:00:00]} e6 {[%emt 0:00:43]}
4. Nc3 {[%emt 0:00:00]} c6 {[%emt 0:00:11]} 5. e3 {[%emt 0:00:00]} Nbd7 {
[%emt 0:00:10]} 6. Qc2 {[%emt 0:00:00]} Bd6 {[%emt 0:00:09]} 7. g4 {
[%emt 0:00:00]} Bb4 {[%emt 0:00:14]} 8. Bd2 {[%emt 0:00:00]} Qe7 {
[%emt 0:00:13]} 9. Rg1 {[%emt 0:00:00]} Bxc3 {[%emt 0:00:08]} 10. Bxc3 {
[%emt 0:00:00]} Ne4 {[%emt 0:00:12]} 11. O-O-O {[%emt 0:00:00]} Nxc3 {
[%emt 0:02:20]} 12. Qxc3 {[%eval 95,18] [%emt 0:11:03]} O-O {
(dxc4) [%emt 0:00:11]} 13. Bd3 {[%eval 81,17] [%emt 0:09:53]} c5 {
(dxc4) [%emt 0:02:36]} 14. Kb1 {[%eval 88,15] [%emt 0:05:45]} cxd4 {
(dxc4) [%emt 0:00:14]} 15. Qxd4 {[%eval 55,16] [%emt 0:06:15]} dxc4 {
[%emt 0:04:16]} 16. Qxc4 {[%eval 37,16] [%emt 0:00:53]} Nc5 {[%emt 0:01:25]}
17. Bc2 {[%eval 55,16] [%emt 0:03:32]} b5 {[%emt 0:02:45]} 18. Qf4 {
[%eval 54,17] [%emt 0:02:13]} Bb7 {[%emt 0:00:09]} 19. g5 {
[%eval 47,16] [%emt 0:02:40]} Bxf3 {[%emt 0:02:04]} 20. Qxf3 {
[%eval 50,16] [%emt 0:00:42]} Rac8 {(g6) [%emt 0:01:42]} 21. Rd4 {
[%eval 40,15] [%emt 0:02:47]} g6 {[%emt 0:00:10]} 22. h4 {
[%eval 36,16] [%emt 0:02:33]} Nd7 {(e5) [%emt 0:04:03]} 23. Rgd1 {
[%eval 33,15] [%emt 0:02:39]} Nb6 {[%emt 0:02:35]} 24. Be4 {
[%eval 37,15] [%emt 0:00:00]} Nc4 {(Rfd8) [%emt 0:02:25]} 25. Qe2 {
[%eval 14,16] [%emt 0:02:39]} e5 {(Rc7) [%emt 0:00:10]} 26. Rd5 {
[%eval 43,16] [%emt 0:02:41]} a6 {[%emt 0:02:38]} 27. Ka1 {
[%eval 47,17] [%emt 0:00:00]} Qb4 {(Rfd8) [%emt 0:02:39]} 28. Bb1 {
[%eval 75,15] [%emt 0:02:22]} Rc7 {[%emt 0:02:51]} 29. Rd8 {
[%eval 42,17] [%emt 0:02:26]} Rc8 {(Qe7) [%emt 0:00:08]} 30. R8d7 {
[%eval 83,16] [%emt 0:01:41]} Na5 {(Nb6) [%emt 0:01:23]} 31. h5 {
[%eval 98,16] [%emt 0:01:40]} Qa4 {[%emt 0:00:57]} 32. R7d3 {
[%eval 106,15] [%emt 0:00:42]} Rc6 {(Rcd8) [%emt 0:06:31]} 33. f4 {
[%eval 113,15] [%emt 0:01:40]} exf4 {[%emt 0:16:30]} 34. hxg6 {
[%eval 283,18] [%emt 0:00:00]} fxg6 {[%emt 0:04:45]} 35. exf4 {
[%eval 303,17] [%emt 0:00:00]} Qxf4 {[%emt 0:02:24]} 36. Rd7 {
[%eval 303,16] [%emt 0:00:00]} Qxg5 {[%emt 0:02:04]} 37. Qe1 {
[%eval 336,16] [%emt 0:00:00]} b4 {[%emt 0:07:00]} 38. Qxb4 {
[%eval 375,16] [%emt 0:00:00]} Rc5 {[%emt 0:02:15]} 39. Qa3 {
[%eval 409,15] [%emt 0:00:00]} Qh5 {[%emt 0:02:24]} 40. Qe3 {
[%eval 476,16] [%emt 0:00:00]} Re5 {[%emt 0:01:48]} 41. Qc3 {
[%eval 533,16] [%emt 0:00:24]} Rfe8 {[%emt 0:03:14]} 42. a3 {
[%eval 588,16] [%emt 0:00:00]} Qg5 {[%emt 0:02:47]} 43. Re1 {
[%eval 660,16] [%emt 0:00:00]} Qf6 {[%emt 0:02:18]} 44. Rxe5 {
[%eval 961,18] [%emt 0:00:24]} Qxe5 {[%emt 0:02:32]} 45. Ba2+ {
[%eval 958,17] [%emt 0:00:16]} Kh8 {[%emt 0:01:13]} 46. Rd8 {
[%eval 1189,20] [%emt 0:01:43]}[/pgn]

[Damir]

Only difference is g4 is on move 7, instead of move 5...

[peter]

And it's a book- move, isn't it?

Edit: At chessprogramming Wiki

https://www.chessprogramming.org/WCCC_2005

I read about the WCCC- game between Zappa and Junior,

https://www.stmintz.com/ccc/index.php?id=443224

Erdogan played a very nice line here I think - the same line Kasparov played
against Junior and Fritz.

anthony

and here's the Kasparov- Junior game

https://www.chessgames.com/perl/chessgame?gid=1260051

[pgn][Event "FIDE Man - Machine WC"]
[Site "New York, NY USA"]
[Date "2003.01.26"]
[EventDate "2003.01.26"]
[Round "1"]
[Result "1-0"]
[White "Garry Kasparov"]
[Black "Deep Junior (Computer)"]
[ECO "D45"]
[WhiteElo "?"]
[BlackElo "?"]
[PlyCount "53"]

1.d4 d5 2.c4 c6 3.Nc3 Nf6 4.e3 e6 5.Nf3 Nbd7 6.Qc2 Bd6 7.g4
dxc4 8.Bxc4 b6 9.e4 e5 10.g5 Nh5 11.Be3 O-O 12.O-O-O Qc7 13.d5
b5 14.dxc6 bxc4 15.Nb5 Qxc6 16.Nxd6 Bb7 17.Qc3 Rae8 18.Nxe8
Rxe8 19.Rhe1 Qb5 20.Nd2 Rc8 21.Kb1 Nf8 22.Ka1 Ng6 23.Rc1 Ba6
24.b3 cxb3 25.Qxb3 Ra8 26.Qxb5 Bxb5 27.Rc7 1-0[/pgn]

[glav]

And it's a book- move, isn't it?

Edit: At chessprogramming Wiki

https://www.chessprogramming.org/WCCC_2005

I read about the WCCC- game between Zappa and Junior,

https://www.stmintz.com/ccc/index.php?id=443224

Erdogan played a very nice line here I think - the same line Kasparov played
against Junior and Fritz.

anthony

and here's the Kasparov- Junior game

https://www.chessgames.com/perl/chessgame?gid=1260051

[pgn][Event "FIDE Man - Machine WC"]
[Site "New York, NY USA"]
[Date "2003.01.26"]
[EventDate "2003.01.26"]
[Round "1"]
[Result "1-0"]
[White "Garry Kasparov"]
[Black "Deep Junior (Computer)"]
[ECO "D45"]
[WhiteElo "?"]
[BlackElo "?"]
[PlyCount "53"]

1.d4 d5 2.c4 c6 3.Nc3 Nf6 4.e3 e6 5.Nf3 Nbd7 6.Qc2 Bd6 7.g4
dxc4 8.Bxc4 b6 9.e4 e5 10.g5 Nh5 11.Be3 O-O 12.O-O-O Qc7 13.d5
b5 14.dxc6 bxc4 15.Nb5 Qxc6 16.Nxd6 Bb7 17.Qc3 Rae8 18.Nxe8
Rxe8 19.Rhe1 Qb5 20.Nd2 Rc8 21.Kb1 Nf8 22.Ka1 Ng6 23.Rc1 Ba6
24.b3 cxb3 25.Qxb3 Ra8 26.Qxb5 Bxb5 27.Rc7 1-0[/pgn]

7) g4 is a well known book move and it is also covered by several theorist in their paper books. Still, I am unable to get it played on move 5 by Stockfish and other engines. The only one that can be induced in considering it is only Leela.