1.g4 opening is losing?

Discussion of anything and everything relating to chess playing software and machines.

Moderators: hgm, Rebel, chrisw

abulmo2
Posts: 433
Joined: Fri Dec 16, 2016 11:04 am
Location: France
Full name: Richard Delorme

Re: 1.g4 opening is losing?

Post by abulmo2 »

Vinvin wrote: Thu Sep 10, 2020 4:58 am
zullil wrote: Thu Feb 06, 2020 5:13 pm
[d]6N1/3n4/3k1b2/8/1r6/5K1Q/8/8 w - - 0 1

Apparently only one move wins. Good luck to all the centaurs. And to all the engines without endgame tables.
There's no draw by the 50 move rule for this position.
https://lichess.org/analysis/6N1/3n4/3k ... _w_-_-_0_1
Click on the book to see the Syzygy DTZ.
?
The "book" gives a DTZ of 1026 and claims that the win is cursed by the 50 move rule.
Richard Delorme
mmt
Posts: 343
Joined: Sun Aug 25, 2019 8:33 am
Full name: .

Re: 1.g4 opening is losing?

Post by mmt »

mmt wrote: Thu Sep 10, 2020 12:46 am
Exa65536 wrote: Fri Apr 17, 2020 4:33 pm
Drawing line versus depth39, as requested
[pgn]1. g4 d5 2. c4 e5 3. cxd5 Qxd5 4. Nf3 Bxg4 5. Nc3 Qa5 6. Ng5 Nc6 7. Qb3 Nd8 8. d3 c6 9. Rg1 Nf6 10. Bd2 Qb6 11. Be3 Qxb3 12. axb3 a6 13. Ra5 Bd6 14. Nge4 Nxe4 15. Rxg4 Nxc3 16. bxc3 g6 17. Kd2 h5 18. Rg1 Ne6 19. Kc2 Kd7 20. h4 Ke7 21. Bh3 Rhg8 22. Bd2 f5 23. b4 Bc7 24. Raa1 Rae8 25. e4 f4 26. Rg2 Kf7 27. f3 Bd8 28. Rh2 Bb6 29. Rg2 Ra8 30. Be1 Rad8 31. Rd1 Ke7 32. Kb3 Kf7 33. Kc4 Nc7 34. d4 Nb5 35. Bf2 exd4 36. cxd4 Kg7 37. Be6 Rgf8 38. Bg1 Rd6 39. Bf5 Kh7 40. Bh3 Kh6 41. Rh2 Kg7 42. Rb2 Rdd8 43. Bf1 Rd7 44. Rbd2 Rfd8 45. Bh3 Rf7 46. Kb3 Kh6 47. Bf1 Rfd7 48. e5 Re8 49. Bc4 Kh7 50. Re1 Bd8 51. Bf2 Nc7 52. Bd3 Rg8 53. Rg1 Nd5 54. Be4 Be7 55. Rdd1 Rdd8 56. Rg2 Rg7 57. Rdg1 Rdg8 58. Rh2 Nxb4 59. Be1 Nd5 60. Bd2 Ne3 61. Bxe3 fxe3 62. Kc4 Rd8 63. Rd1 a5 64. Kd3 Bc5 65. Kxe3 Rgd7 66. Rhd2 Ba7 67. f4 a4 68. f5 Re7 69. Kf4 gxf5 70. Bxf5+ Kh8 71. Ke4 Bb8 72. Rd3 Rd5 73. Bc8 Rd8 74. Bf5 b5 75. Rc1 Rc7 76. Rg1 Rg7 77. Rc1 Rc7 78. Rg1 Rg7 79. Rxg7 Kxg7 80. Rg3+ Kf8 81. Be6 Ke7 82. Bf5 Kf8 83. Rg6 Ba7 84. Rf6+ Ke7 85. Re6+ Kd7 86. Rg6+
[/pgn]
SF NNUE slightly prefers 8... h6 to 8... c6 from the start. Do you have a drawing continuation after this move?

[d]r2nkbnr/ppp2pp1/7p/q3p1N1/6b1/1QNP4/PP2PP1P/R1B1KB1R w KQkq - 0 9
I ran SF NNUE very deep from this position. And the result at depth 79 is... unclear. -1.5.
1.Rg1 Nf6 2.Rxg4 Nxg4 3.Nxf7 Nxf7 4.Qe6+ Be7 5.Qxg4 0-0 6.Bg2 c6 7.Be4 Bb4 8.Kf1 Qd8 9.Qg6 Ng5 10.Bxg5 Qxg5 11.Qxg5 hxg5 12.Nd1 a5 13.a3 Be7 14.h3 Ra6 15.Rc1 Rb6 16.Rc2 Kf7 17.Nc3 Ra8 18.Na4 Rba6 19.Bf3 Ke8 20.e3 Kf7 21.Bh5+ Kf8 22.Bf3 Rd8 23.Ke2 Kf7 24.Kf1 Kg6 25.Ke2 Rh8 26.Bg4 Rh4 27.Nc3 Kf7 28.Ne4 Rb6 29.Nc3 Rh8 30.Ne4 Rb5 31.Kf1 Rb3 32.Nc3 Rb6 33.Ne4 Rd8 34.Be2 a4 35.Rd2 g6 36.Bg4 Rb5 37.Kg2 Ra8 38.Nc3 Rc5 39.Kf3 Rca5 40.Rc2 Rd8 41.Rd2 Rh8 42.Ke2 Rha8 43.Rc2 Kg7 44.Rc1
mmt
Posts: 343
Joined: Sun Aug 25, 2019 8:33 am
Full name: .

Re: 1.g4 opening is losing?

Post by mmt »

Still -1.5 at depth 80. Since the eval doesn't vary in the last several plies, Grob now looks more drawish than before.
Alayan
Posts: 550
Joined: Tue Nov 19, 2019 8:48 pm
Full name: Alayan Feh

Re: 1.g4 opening is losing?

Post by Alayan »

I don't think it's very meaningful, a single search from such a position with so much material on board isn't going to solve it.

Over at CDBCN, the evaluation of the Grob is at -143cp and it has been trending down. For every single potential draw line that get suggested, just focusing it by going deeper ends up finding a bust. The sheer amount of lines that white can throw at black, however is practically limitless.

The critical test of 1. g4 d5 2. c4 is Bxg4, not e5, according to CDBCN.
mmt
Posts: 343
Joined: Sun Aug 25, 2019 8:33 am
Full name: .

Re: 1.g4 opening is losing?

Post by mmt »

I don't see ChessDBCN as meaningful here. Based on http://talkchess.com/forum3/viewtopic.php?t=71764 it's only depth 22. Even if it's deeper now, I looked at these positions much deeper and also with 7-piece TBs and 450 GB RAM. I'll check 2... Bxg4 but it didn't look as good.
Alayan
Posts: 550
Joined: Tue Nov 19, 2019 8:48 pm
Full name: Alayan Feh

Re: 1.g4 opening is losing?

Post by Alayan »

The leaf evals are depth 22, but the tree is massive. As you know, a depth 80 search with SF doesn't mean looking at depth 79 all children, then depth 78 all their children... There is a lot of reductions on all moves that look bad. Searching a million nodes with depth 22 leaves can be quite competitive.

ChessDB has also the advantage of persistency, while you lose your massive hash if you stop Stockfish.
mmt
Posts: 343
Joined: Sun Aug 25, 2019 8:33 am
Full name: .

Re: 1.g4 opening is losing?

Post by mmt »

I wouldn't expect my analysis to be useful for popular openings but 1. g4 d5 2. c4 is not exactly common, so I expect that it wasn't analyzed nearly as deeply. But I'm not certain on what the apparent depth number displayed by ChessDB.cn interface under the notes column means exactly and how to compare it to the depth reached by engines. Or how it does pruning since it's clearly not analyzing all moves. Also, I'm analyzing with SF NNUE and I'd guess ChessDB.cn used older versions of SF.
Alayan
Posts: 550
Joined: Tue Nov 19, 2019 8:48 pm
Full name: Alayan Feh

Re: 1.g4 opening is losing?

Post by Alayan »

ChessDB's SF sometimes gets updated, it's currently using a NNUE-based SF version. I'm not sure it makes a massive difference for the task of busting the Grob, though.

Let us know what your Stockfish search suggests in the Bxg4 line as a defense for white.

Also, while the DB wouldn't automatically try to analyze the Grob a lot because 1. g4 is bad, this line has seen massive user-driven exploration. 1. g4 has much better exploration than say 1. f3.
jp
Posts: 1470
Joined: Mon Apr 23, 2018 7:54 am

Re: 1.g4 opening is losing?

Post by jp »

mmt wrote: Sat Sep 26, 2020 3:55 pm I wouldn't expect my analysis to be useful for popular openings but 1. g4 d5 2. c4 is not exactly common, so I expect that it wasn't analyzed nearly as deeply. But I'm not certain on what the apparent depth number displayed by ChessDB.cn interface under the notes column means exactly and how to compare it to the depth reached by engines. Or how it does pruning since it's clearly not analyzing all moves.
Certainly, earlier this year, it did not look like it was useful for this opening. We'd want some sort of stability in its scores before we can begin to take it seriously.

Ovyron wrote: Thu Jan 30, 2020 6:30 am
Alayan wrote: Sat Jan 25, 2020 7:38 pm So, white needs to deviate from this line somewhere. ChessDBCN hasn't found something convincing yet, its score after 7. ... Ne7 has moved to -1.30 after I fed it the refutations to its preferred line.
I managed to get the score up to -0.90 by feeding it my refutations to its black's main attacks.

Looks like you can just pick a side and refute its lines and make its score whatever you want.
Alayan wrote: Thu Jan 30, 2020 4:22 pm I can confirm you had it pushed down over -1.00. I pushed it back to -1.30 by feeding it counter-analysis.

But it likes Rb5 after Na4 in the h5 line, while my homefish in the end preferred Rb8 (Rb5 was the top move for a few depths). It could be refuted back and forth for a while I think.
Alayan
Posts: 550
Joined: Tue Nov 19, 2019 8:48 pm
Full name: Alayan Feh

Re: 1.g4 opening is losing?

Post by Alayan »

The only true values of a chess position are draw and mate in X. A score like 150cp is always incorrect from a chess truth perspective, it's only a useful approximation for humans and engines to denote a position that's very difficult to hold, maybe losing by force, maybe not. So of course it can't be stable.

If you feed the DB with a way to draw against its best attack, or to win against its best defence, you'll move the score one way or another. But it already contains a lot of data. And remember, you don't need a single drawing/winning line, but many, against the different options available to the other side.

So far, no drawing attempt has stuck, there is always a way to push the evaluation back to a high cp score either by going deeper in the line or by switching to another attacking move. A few days ago, The evaluation after 1. g4 was 140cp, now it's 150cp. I've used the live AI to play games from the leaf positions of the best-drawing attempts, with the resulting positions automatically added for DB evaluation, and it has consistently allowed to grow black's eval, cp by cp.