1.g4 opening is losing?

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

Moderators: bob, hgm, Harvey Williamson

Forum rules
This textbox is used to restore diagrams posted with the [d] tag before the upgrade.
zullil
Posts: 6209
Joined: Mon Jan 08, 2007 11:31 pm
Location: PA USA
Full name: Louis Zulli

Re: 1.g4 opening is losing?

Post by zullil » Thu Feb 06, 2020 4:37 pm

jp wrote:
Thu Feb 06, 2020 4:31 pm
zullil wrote:
Thu Feb 06, 2020 4:13 pm
Apparently only one move wins. Good luck to all the centaurs. And to all the engines without endgame tables.
For sure. There must also be (or I hope there are) simpler examples, where "simpler" probably means some combination of fewer pieces and smaller DTM (i.e. not ~500 or ~1000).
Yes, I simply chose a "random" example. And imagine how many such positions might exist. We could redefine chess to have certain 8-man initial positions and no one would be able to give the theoretical result of the game. Forget about deciding about 1. g4 :D
Last edited by zullil on Thu Feb 06, 2020 4:38 pm, edited 1 time in total.

User avatar
Ovyron
Posts: 4256
Joined: Tue Jul 03, 2007 2:30 am

Re: 1.g4 opening is losing?

Post by Ovyron » Thu Feb 06, 2020 4:38 pm

The question is still if those examples are relevant, because the winning player can just tag the position as drawn (who cares if it wins if I can't find the win?) and go for a different won position that is clear.

The job of the winning player is not to maximize the engine's eval or play the fastest way to mate, their job is to play into positions that are the easiest to win, and "only one move wins" positions would be hard to win by definition, and could be just tagged as draws and avoided.

zullil
Posts: 6209
Joined: Mon Jan 08, 2007 11:31 pm
Location: PA USA
Full name: Louis Zulli

Re: 1.g4 opening is losing?

Post by zullil » Thu Feb 06, 2020 4:40 pm

Ovyron wrote:
Thu Feb 06, 2020 4:38 pm
The question is still if those examples are relevant, because the winning player can just tag the position as drawn (who cares if it wins if I can't find the win?) and go for a different won position that is clear.

The job of the winning player is not to maximize the engine's eval or play the fastest way to mate, their job is to play into positions that are the easiest to win, and "only one move wins" positions would be hard to win by definition, and could be just tagged as draws and avoided.
And how will you even recognize such positions? Say those with 11 men? Or 19? :wink:

jp
Posts: 1345
Joined: Mon Apr 23, 2018 5:54 am

Re: 1.g4 opening is losing?

Post by jp » Thu Feb 06, 2020 4:45 pm

Ovyron wrote:
Thu Feb 06, 2020 4:38 pm
The job of the winning player is not to maximize the engine's eval or play the fastest way to mate...
We're not talking about the fastest way to mate (which even 7-man TBs won't help with). We're talking about the one lonely move that does not throw away the win, and we don't know how many or which positions those are with >7 men.

Ovyron wrote:
Thu Feb 06, 2020 4:38 pm
... "only one move wins" positions ... could be just tagged as draws and avoided.
Even if you had this magic tagging power (the only known source of this magic power is... yep... tablebases!), you cannot avoid a position if it is the current position or the start position!
Last edited by jp on Thu Feb 06, 2020 4:51 pm, edited 1 time in total.

zullil
Posts: 6209
Joined: Mon Jan 08, 2007 11:31 pm
Location: PA USA
Full name: Louis Zulli

Re: 1.g4 opening is losing?

Post by zullil » Thu Feb 06, 2020 4:51 pm

zullil wrote:
Thu Feb 06, 2020 4:13 pm
jp wrote:
Thu Feb 06, 2020 4:03 pm
zullil wrote:
Thu Feb 06, 2020 3:51 pm
Right. Is there a handy example of a 7-man position that is a theoretical draw for the side to move, but for which only one or two non-obvious moves hold the draw?
I'm interested in finding such positions too, e.g. the simplest possible endgame positions that are too hard for computers alone or even centaurs. They'd probably need to be at least 5-man, I guess.


Apparently only one move wins. Good luck to all the centaurs. And to all the engines without endgame tables.
Stockfish (with 6-man tables) has Qf5 with eval +0.38 at depth 54. Wrong move, and eval is off by infinity! :D

Clearly I need to find a "centaur" to help.

jp
Posts: 1345
Joined: Mon Apr 23, 2018 5:54 am

Re: 1.g4 opening is losing?

Post by jp » Thu Feb 06, 2020 4:53 pm

zullil wrote:
Thu Feb 06, 2020 4:51 pm
Stockfish (with 6-man tables) has Qf5 with eval +0.38 at depth 54. Wrong move, and eval is off by infinity! :D
Let it keep running, so its humiliation will be complete. :wink: 8-)

But really (and this ties to my previous posts) the greatest humiliation is once the depths start being comparable to the DTM and it still has no clue, which is why I'd like short examples. Unfortunately, we're not going to get SF to depth 500 or 1000 at this time.

zullil
Posts: 6209
Joined: Mon Jan 08, 2007 11:31 pm
Location: PA USA
Full name: Louis Zulli

Re: 1.g4 opening is losing?

Post by zullil » Thu Feb 06, 2020 5:09 pm

jp wrote:
Thu Feb 06, 2020 4:53 pm
zullil wrote:
Thu Feb 06, 2020 4:51 pm
Stockfish (with 6-man tables) has Qf5 with eval +0.38 at depth 54. Wrong move, and eval is off by infinity! :D
Let it keep running, so its humiliation will be complete. :wink: 8-)

But really (and this ties to my previous posts) the greatest humiliation is once the depths start being comparable to the DTM and it still has no clue, which is why I'd like short examples. Unfortunately, we're not going to get SF to depth 500 or 1000 at this time.
Cfish has done better. It has the right move, though its current evaluation is not at all convincing. Of course, Cfish is currently using 6-man tables. I should disable those.

+0.72 1. Kg2 Rb2+ 2. Kf1 Rb1+ 3. Ke2 Rb2+ 4. Kd1 Rb1+ 5. Kc2 Rb2+ 6. Kc1 Rb5 7. Qh2+ Re5 8. Qh6 Rc5+ 9. Kd2 Rd5+ 10. Ke2 Re5+ 11. Kd3 Rd5+ 12. Ke4 Nc5+ 13. Ke3 Re5+ 14. Kd2 Ne4+ 15. Kd3 Re6 16. Qf4+ Kc6 17. Qf3 Bg5 18. Kd4 Bd8 19. Qf5 Ng5 20. Kc4 Re4+ 21. Kc3 Re6 22. Kd2 Ne4+ 23. Kc2 Nc5 24. Qh5 Kb5 25. Kd1 Ba5 26. Nh6 Re1+ 27. Kc2 Bc7 28. Nf5 Re4 29. Kd1 Kb4 30. Qf7 Be5 31. Qf8 Bf4 32. Qa8 Kb5 33. Qd5 Be5 34. Kd2 Kb4 35. Kc2 (depth 54, 0:30:43)

jp
Posts: 1345
Joined: Mon Apr 23, 2018 5:54 am

Re: 1.g4 opening is losing?

Post by jp » Thu Feb 06, 2020 6:02 pm

zullil wrote:
Thu Feb 06, 2020 5:09 pm
Cfish has done better. It has the right move, though its current evaluation is not at all convincing. Of course, Cfish is currently using 6-man tables. I should disable those.

+0.72 1. Kg2 ... 35. Kc2 (depth 54, 0:30:43)
Is this whole line correct, or just the first move? How many plies in the correct solution before conversion to 6 men?

mmt
Posts: 216
Joined: Sun Aug 25, 2019 6:33 am
Full name: .

Re: 1.g4 opening is losing?

Post by mmt » Thu Feb 06, 2020 6:07 pm

zullil wrote:
Thu Feb 06, 2020 12:33 pm
Without 7-man endgame tables, Stockfish-dev's (static) evaluattion of this position is +4.67. But it's a draw. How many similar positions are there, say with eight or nine men, that Stockfish totally misevaluates?
Well yeah, that's why I was saying we can get a probability, not a certainty. It wouldn't be "solved" but it'd be something like 99.9% sure it's losing. The chances of such positions occurring in real games are very, very low. BTW, LC0 without EGTBs evaluates it as around 0.2 right away.

I wonder if there is a larger or a small percentage of such positions going up to 8, 9, 10-piece EGTBs. I'm guessing smaller. We could take random 5-piece and 6-piece EGTBs positions to see where programs without EGTBs misevaluate compared to EGTBs and it would probably be the same ratio as when going up to more pieces.

jp
Posts: 1345
Joined: Mon Apr 23, 2018 5:54 am

Re: 1.g4 opening is losing?

Post by jp » Thu Feb 06, 2020 6:17 pm

mmt wrote:
Thu Feb 06, 2020 6:07 pm
zullil wrote:
Thu Feb 06, 2020 12:33 pm
Without 7-man endgame tables, Stockfish-dev's (static) evaluation of this position is +4.67. But it's a draw.
Well yeah, that's why I was saying we can get a probability, not a certainty. It wouldn't be "solved" but it'd be something like 99.9% sure it's losing. The chances of such positions occurring in real games are very, very low. BTW, LC0 without EGTBs evaluates it as around 0.2 right away.
I disagree. The position there wasn't even remotely unusual. There must be millions like that one with a fortress.

Has Leela's endgame play improved? Otherwise any good (difficult) endgame evals by it coud be claimed to be largely fluke.

mmt wrote:
Thu Feb 06, 2020 6:07 pm
I wonder if there is a larger or a small percentage of such positions going up to 8, 9, 10-piece EGTBs.
We could take random 5-piece and 6-piece EGTBs positions to see where programs without EGTBs misevaluate
This would be interesting. What's a good way to do it?

Post Reply