1.g4 opening is losing?

[mmt]

I disagree. The position there wasn't even remotely unusual. There must be millions like that one with a fortress.

Millions are nothing though. There are 424 trillion 7-piece EGTB positions. I'm guessing quite a bit less than 0.1% of positions are like that (let's say both LC0 and SF 11 misevaluate severly) in 7-piece EGTBs and even smaller % in 8-piece EGTBs (since 7-piece engine scores don't matter). So we can still get a high chance that 1. g4 is lost.

[jp]

There are 424 trillion 7-piece EGTB positions. I'm guessing quite a bit less than 0.1% of positions are like that

Well, how do we test this, i.e. automate selection of random endgame positions for starters?

We'd also need to decide what a pass or fail for the engine would be.

The examples with fortresses are only one class of positions that fool computers, but even just that subset comes up a lot in analysis of disputed positions in this forum.

[mmt]

Well, how do we test this, i.e. automate selection of random endgame positions for starters?

We'd also need to decide what a pass or fail for the engine would be.

Yes, after these two steps we'd just run them with and without EGTBs and it's just a simple calculation. It would be nice to not evaluate impossible positions like this:
[d]8/8/3k4/8/8/8/3K1PPP/6B1 w - - 0 1
You might want to randomize in a way that would correspond to real positions occurring in games also (e.g. by playing out games with a bit of randomness or using games databases and getting the needed positions). I mean this won't ever happen in a real, competitive game:
[d]8/8/3k4/8/8/8/3K1BB1/5BBB w - - 0 1
but there are a lot of positions like this in EGTBs.

[jp]

You might want to randomize in a way that would correspond to real positions occurring in games also (e.g. by playing out games with a bit of randomness or using games databases and getting the needed positions).

Yes, I'm not sure how to weight it towards "common" positions, because who's to say what's more common in human (or computer) endgames is more common in higher-level chess?

For the test, I wonder whether the depth or nodes you allow the engines should be a function of the number of pieces. Engines may not have a problem with 4-man positions, but that's partly because they can calculate everything through to the end.

[Dann Corbit]

Here are the named 1.g4 openings, ordered by ce:

Code: Select all

rnbqk1nr/pp1pppbp/8/2p3B1/3P4/8/PPP1PPPP/RN1QKBNR w KQkq - acd 50; acs 6480; bm c3; ce 123; id "Grob.0713"; pm c3; pv c3; Opening Grob: Fritz gambit *;
rnbqkbnr/pppppp1p/8/6p1/8/8/PPPPPPPP/RNBQKBNR w KQkq - acd 46; acs 6480; bm d4; ce 92; id "Grob.0700"; pm d4; pv d4 g4; Opening Grob's attack *;
rnbqkbnr/ppppp1pp/8/5p2/6P1/8/PPPPPP1P/RNBQKBNR w KQkq - acd 52; acs 6480; bm gxf5; ce 90; cce -444; id "Grob.0585"; pm gxf5; pv gxf5; white_wins 0; black_wins 5; draws 0; Opening A00n Grob: Alessi Gambit;
rnbqk1nr/ppppppbp/8/8/3P2p1/2P5/PP2PPPP/RNBQKBNR w KQkq - acd 50; acs 6480; bm h3; ce 85; id "Grob.0707"; pm h3; pv h3 d5 hxg4 Bxg4 Nf3 Nd7 Qb3 Ngf6 Bf4 Qc8 Ne5 Be6 Nxd7 Nxd7 e3 c5 Nd2 h5 Be2 h4 Bg5 c4 Qa4 h3 gxh3 Rxh3 Rxh3 Bxh3 O-O-O Qc6 Qc2 Nf6 Rg1 Bf8 f3 b5 e4 O-O-O b3 Be6 Be3 Nd7 a4 a6 Bf4 Nb6 axb5 axb5 Qa2 Kb7 Qb2 Rc8 bxc4 dxc4 d5 Qc5; Opening Grob: spike attack *;
rnbqkbnr/pppppp1p/8/6p1/6P1/8/PPPPPP1P/RNBQKBNR w KQkq - acd 48; acs 6480; bm Nc3; ce 25; cce -302; id "Grob.0267"; pm Nc3; pv Nc3 d5 d4 Bxg4 Bxg5 Nc6 f3 Bh5 Bh3 Bg7 e3 Bf6 Bf4 e6 Qe2 Bg5 Bg3 Qf6 Bg4 Bxg4 fxg4 Bh4 O-O-O Bxg3 hxg3 O-O-O Rh4 Nge7 Rf1 Qg7 Qf3 f5 Nge2 Rhf8 Nf4 Qg8 gxf5 Rxf5 Rh5 Rdf8 Rxf5 Rxf5 g4 Rf8 Qh3 Kb8 b3 Rf7 Rh1 e5 dxe5 Nxe5 Nfxd5 Nxd5 Nxd5 Qxg4 Qxg4 Nxg4; white_wins 0; black_wins 18; draws 10; Opening A00n Grob: Double Grob;
q3kbnr/p1pnpppp/8/8/2Pp2b1/8/PP1PPP1P/RNBQK1NR w KQk - acd 50; acs 6480; bm f3; ce -49; cce -3; id "Grob.0106"; pm f3; pv f3; white_wins 70; black_wins 72; draws 35; Opening Grob Opening: Grob Gambit. Fritz Gambit Romford Countergambit 1.g4 d5 2.Bg2 Bxg4 3.c4 d4 4.Bxb7 Nd7 5.Bxa8 Qxa8; CaxtonID: 738; ECO: A00;
rnbqkbnr/ppp2ppp/8/3pp3/6P1/8/PPPPPPBP/RNBQK1NR w KQkq - acd 49; acs 6480; bm d4; ce -50; cce -68; id "Grob.0025"; pm d4; pv d4; white_wins 270; black_wins 417; draws 246; Opening A00o Grob Gambit: e5;
rn1qkbnr/ppp1pppp/8/8/2Pp2b1/8/PP1PPPBP/RNBQK1NR w KQkq - acd 52; acs 6480; bm Bxb7; ce -57; cce -140; id "Grob.0036"; pm Bxb7; pv Bxb7 Nd7; white_wins 97; black_wins 253; draws 146; Opening ECO:A00; Opening: Grob; Variation Romford counter-gambit; 1. g4 d5 2. Bg2 Bxg4 3. c4 d4 *;
r1bqkbnr/pppp1ppp/2n5/4p3/6P1/7P/PPPPPP2/RNBQKBNR w KQkq - acd 40; acs 6840; bm c4; ce -74; cce -67; id "Grob.0183"; pm Bg2 {5} c4 {3} Nc3 {1} d3 {1}; pv c4; white_wins 18; black_wins 33; draws 42; Opening Grob Opening: London Defense. 1.g4 e5 2.h3 Nc6; CaxtonID: 743; ECO: A00;
rnbqkbnr/pppp1ppp/8/4p3/6P1/8/PPPPPP1P/RNBQKBNR w KQkq - acd 49; acs 6480; bm d4; ce -86; cce -85; id "Grob.0021"; pm d4; pv d4 exd4; white_wins 467; black_wins 771; draws 340; Opening A00n Grob: 1...e5;
rnbqk2r/pp2nppp/2pb4/3p4/2PPp1P1/2N4P/PP2PPB1/R1BQK1NR w KQkq - acd 43; acs 2100; bm Bd2; ce -87; cce -175; id "Grob.0017"; pm Qb3 {54} Bg5 {8} e3 {3} g5 {2} Qc2 {2}; pv Bd2; white_wins 383; black_wins 1102; draws 328; Opening Grob Opening: Keene Defense. Main Line 1.g4 d5 2.h3 e5 3.Bg2 c6 4.d4 e4 5.c4 Bd6 6.Nc3 Ne7; CaxtonID: 742; ECO: A00;
rnbqkbnr/ppp1ppp1/8/7p/4p1P1/2N5/PPPP1P1P/R1BQKBNR w KQkq - acd 49; acs 6480; bm g5; ce -88; id "Grob.0709"; pm g5; pv g5; Opening Grob Opening: Zilbermints Gambit. Schiller Defense 1.g4 d5 2.e4 dxe4 3.Nc3 h5; CaxtonID: 748; ECO: A00;
rnbqkbnr/pp2pppp/2p5/3p4/6P1/8/PPPPPPBP/RNBQK1NR w KQkq - acd 45; acs 2100; bm h3; ce -89; cce -133; id "Grob.0010"; pm h3 {53} g5 {20} c4 {7} e3 {4} e4 {1}; pv h3 e5; white_wins 569; black_wins 1319; draws 611; Opening A00o Grob Gambit: 2...c6;
rn1qkbnr/ppp1pppp/8/3p4/6b1/8/PPPPPPBP/RNBQK1NR w KQkq - acd 46; acs 2100; bm c4; ce -92; cce -83; id "Grob.0019"; pm c4 {60} Nc3 {1}; pv c4; white_wins 407; black_wins 714; draws 574; Opening A00o Grob Gambit Accepted;
rnbqkbnr/ppp1pppp/8/3p4/6P1/8/PPPPPP1P/RNBQKBNR w KQkq - acd 50; acs 26812; bm g5; ce -93; cce -134; id "Grob.0003"; pm Bg2 {158} h3 {84} e3 {12} c4 {4} g5 {4} b3 {2} f4 {2} f3 {1}; pv g5; white_wins 1748; black_wins 4047; draws 1869; Opening A00o Grob: 1...d5;
rnbqkbnr/pp3ppp/2p5/3pp3/6P1/7P/PPPPPPB1/RNBQK1NR w KQkq - acd 44; acs 2100; bm Nc3; ce -101; cce -161; id "Grob.0006"; pm d4 {87} d3 {16} e4 {3} c4 {2} Nc3 {2} b3 {1}; pv Nc3 Ne7; white_wins 678; black_wins 1829; draws 631; Opening Grob Opening: Keene Defense. 1.g4 d5 2.h3 e5 3.Bg2 c6; CaxtonID: 741; ECO: A00;

The ones at the top are winning, and the ones at the bottom are losing and the ones in the middle are drawish.
The problem is that the ones at the top are not really achievable in game play.

[zullil]

You might want to randomize in a way that would correspond to real positions occurring in games also (e.g. by playing out games with a bit of randomness or using games databases and getting the needed positions).

Yes, I'm not sure how to weight it towards "common" positions, because who's to say what's more common in human (or computer) endgames is more common in higher-level chess?

For the test, I wonder whether the depth or nodes you allow the engines should be a function of the number of pieces. Engines may not have a problem with 4-man positions, but that's partly because they can calculate everything through to the end.

It would be interesting to know just how well/badly Stockfish statically evaluates rook and pawn endgames.

For example, this one is a draw, but Stockfish's static eval is +1.46. Imagine what might happen with, say, 9-man rook and pawn positions. And these wrong evaluations might "poison" the evaluations of all sorts of middlegame positions.

[d]8/4kp1R/8/4KP1P/8/1r6/8/8 w - - 0 1

Code: Select all

./stockfish 
Stockfish 060220 64 BMI2 by T. Romstad, M. Costalba, J. Kiiski, G. Linscott
position fen 8/4kp1R/8/4KP1P/8/1r6/8/8 w - - 0 1
d

 +---+---+---+---+---+---+---+---+
 |   |   |   |   |   |   |   |   |
 +---+---+---+---+---+---+---+---+
 |   |   |   |   | k | p |   | R |
 +---+---+---+---+---+---+---+---+
 |   |   |   |   |   |   |   |   |
 +---+---+---+---+---+---+---+---+
 |   |   |   |   | K | P |   | P |
 +---+---+---+---+---+---+---+---+
 |   |   |   |   |   |   |   |   |
 +---+---+---+---+---+---+---+---+
 |   | r |   |   |   |   |   |   |
 +---+---+---+---+---+---+---+---+
 |   |   |   |   |   |   |   |   |
 +---+---+---+---+---+---+---+---+
 |   |   |   |   |   |   |   |   |
 +---+---+---+---+---+---+---+---+

Fen: 8/4kp1R/8/4KP1P/8/1r6/8/8 w - - 0 1
Key: D3383250DDB43FBF
Checkers: 
eval
     Term    |    White    |    Black    |    Total   
             |   MG    EG  |   MG    EG  |   MG    EG 
 ------------+-------------+-------------+------------
    Material |  ----  ---- |  ----  ---- |  0.01  1.29
   Imbalance |  ----  ---- |  ----  ---- |  0.00  0.00
       Pawns | -0.11 -0.27 | -0.02 -0.07 | -0.08 -0.20
     Knights |  0.00  0.00 |  0.00  0.00 |  0.00  0.00
     Bishops |  0.00  0.00 |  0.00  0.00 |  0.00  0.00
       Rooks |  0.00  0.00 |  0.22  0.12 | -0.22 -0.12
      Queens |  0.00  0.00 |  0.00  0.00 |  0.00  0.00
    Mobility | -0.01  0.38 |  0.27  0.80 | -0.28 -0.42
 King safety | -0.63 -0.24 | -0.38 -0.05 | -0.24 -0.19
     Threats |  0.34  0.49 |  0.32  0.28 |  0.01  0.21
      Passed |  1.11  1.32 |  0.00  0.00 |  1.11  1.32
       Space |  0.00  0.00 |  0.00  0.00 |  0.00  0.00
  Initiative |  ----  ---- |  ----  ---- | -0.06 -0.29
 ------------+-------------+-------------+------------
       Total |  ----  ---- |  ----  ---- |  0.25  1.61

Total evaluation: 1.46 (white side)

[Ovyron]

And how will you even recognize such positions? Say those with 11 men? Or 19?

Here's a 20men position where black wins by force:

[d]3r2k1/1Br2ppp/1p6/p5P1/2bNP3/n1P1BP2/7P/R5K1 b - -

If you don't know how do I know no software or hardware would help you

[zullil]

And how will you even recognize such positions? Say those with 11 men? Or 19?

Here's a 20men position where black wins by force:

[d]3r2k1/1Br2ppp/1p6/p5P1/2bNP3/n1P1BP2/7P/R5K1 b - -

If you don't know how do I know no software or hardware would help you

I doubt you know. I have no doubt you think you know.

[Ovyron]

I know. I can't prove it, but I know

People confuse proof with knowledge.

Also, there was this guy making claims in that game, I wonder if you can recognize who was it...

1. g4 d5 2. g5 e5 3. d4 exd4 4. Nf3 c5 5. Bg2 Ne7 6. c3 dxc3 7. Nxc3 Nbc6 8. O-O d4 9. Ne4 Ng6 10. a3 Bg4 11. Bd2 Bd6 12. Rc1 O-O 13. Nxc5 Bxc5 14. Rxc5 Qd7 15. Qb3 Rad8 16. Re1 Be6 17. Qd3 Rfe8 18. e4 b6 19. Rcc1 Bg4 20. Rxc6 Qxc6 21. Nxd4 Qc5 22. Be3 Ne5 23. Qc3 Qxc3 24. bxc3 Rc8 25. f3 Be6 26. Nb5 Red8 27. Bd4 Nc6 28. Be3 a6 29. Nd4 Ne5 30. Rc1 Nc4 31. Bf4 Nxa3 32. Bf1 a5 33. Ba6 Rc5 34. Be3 Bc4 35. Bb7 Rc7 36. Ra1

[d]3r2k1/1Br2ppp/1p6/p5P1/2bNP3/n1P1BP2/7P/R5K1 b - -

Best according to Stockfish, but this game has been over for a while now. Eval is approaching -6.

This guy was saying that the game was already over? So you can get in contact with him and tell him he can't know that without 20men tablebases!

[zullil]

I know. I can't prove it, but I know

People confuse proof with knowledge.

Also, there was this guy making claims in that game, I wonder if you can recognize who was it...

1. g4 d5 2. g5 e5 3. d4 exd4 4. Nf3 c5 5. Bg2 Ne7 6. c3 dxc3 7. Nxc3 Nbc6 8. O-O d4 9. Ne4 Ng6 10. a3 Bg4 11. Bd2 Bd6 12. Rc1 O-O 13. Nxc5 Bxc5 14. Rxc5 Qd7 15. Qb3 Rad8 16. Re1 Be6 17. Qd3 Rfe8 18. e4 b6 19. Rcc1 Bg4 20. Rxc6 Qxc6 21. Nxd4 Qc5 22. Be3 Ne5 23. Qc3 Qxc3 24. bxc3 Rc8 25. f3 Be6 26. Nb5 Red8 27. Bd4 Nc6 28. Be3 a6 29. Nd4 Ne5 30. Rc1 Nc4 31. Bf4 Nxa3 32. Bf1 a5 33. Ba6 Rc5 34. Be3 Bc4 35. Bb7 Rc7 36. Ra1

[d]3r2k1/1Br2ppp/1p6/p5P1/2bNP3/n1P1BP2/7P/R5K1 b - -

Best according to Stockfish, but this game has been over for a while now. Eval is approaching -6.

This guy was saying that the game was already over? So you can get in contact with him and tell him he can't know that without 20men tablebases!

That guy was writing informally.

He meant that, based on possibly incorrect information provided by Stockfish, it was his strong conjecture that White is lost.

Rather not argue about our epistemological differences. Without a proof tree as support, statements about the theoretical value of a position are (to me) conjectures.