Cursed win at TCEC

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Joerg Oster
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Location: Germany

Re: fortress_draw_rule

Post by Joerg Oster »

Lyudmil Tsvetkov wrote:
hgm wrote:Well, Duncan already posted that it is a mate in 31. So what else do you need to make yourself look foolish?
getting a reply from Duncan, and asking Milos the same thing, to acknowledge SF is able to mate easily, are 2 different things.

besides, I did not ask if it is mate, but whether SF is able to deliver the mate without tbs. also 2 different things.

sometimes people are also in a hurry and post, before reading the whole thread.

the point is, if SF is able to mate below:

[d]K5Q1/8/8/8/5bb1/6k1/8/8 w - - 0 1

why adjudicate draw? why on Earth?

that is the real question, and not whether I have posted a mate shorter than 50 instead of a longer one. I guess everyone understands that.
OK, I did you the favor.
Here is the result of a self-match, 10 games, tc=20+0.2, no EGTBs:

Code: Select all

Started game 1 of 10 (SF-Master vs SF-Master)
Started game 2 of 10 (SF-Master vs SF-Master)
Started game 3 of 10 (SF-Master vs SF-Master)
Finished game 1 (SF-Master vs SF-Master): 1/2-1/2 {Draw by fifty moves rule}
Score of SF-Master vs SF-Master: 0 - 0 - 1  [0.500] 1
Started game 4 of 10 (SF-Master vs SF-Master)
Finished game 3 (SF-Master vs SF-Master): 1/2-1/2 {Draw by fifty moves rule}
Score of SF-Master vs SF-Master: 0 - 0 - 2  [0.500] 2
ELO difference: 0
Started game 5 of 10 (SF-Master vs SF-Master)
Finished game 2 (SF-Master vs SF-Master): 1/2-1/2 {Draw by fifty moves rule}
Score of SF-Master vs SF-Master: 0 - 0 - 3  [0.500] 3
Started game 6 of 10 (SF-Master vs SF-Master)
Finished game 5 (SF-Master vs SF-Master): 1/2-1/2 {Draw by fifty moves rule}
Score of SF-Master vs SF-Master: 0 - 0 - 4  [0.500] 4
ELO difference: 0
Started game 7 of 10 (SF-Master vs SF-Master)
Finished game 6 (SF-Master vs SF-Master): 1/2-1/2 {Draw by fifty moves rule}
Score of SF-Master vs SF-Master: 0 - 0 - 5  [0.500] 5
Started game 8 of 10 (SF-Master vs SF-Master)
Finished game 4 (SF-Master vs SF-Master): 1/2-1/2 {Draw by fifty moves rule}
Score of SF-Master vs SF-Master: 0 - 0 - 6  [0.500] 6
ELO difference: 0
Started game 9 of 10 (SF-Master vs SF-Master)
Finished game 8 (SF-Master vs SF-Master): 1/2-1/2 {Draw by fifty moves rule}
Score of SF-Master vs SF-Master: 0 - 0 - 7  [0.500] 7
Started game 10 of 10 (SF-Master vs SF-Master)
Finished game 7 (SF-Master vs SF-Master): 1/2-1/2 {Draw by fifty moves rule}
Score of SF-Master vs SF-Master: 0 - 0 - 8  [0.500] 8
ELO difference: 0
Finished game 9 (SF-Master vs SF-Master): 1/2-1/2 {Draw by fifty moves rule}
Score of SF-Master vs SF-Master: 0 - 0 - 9  [0.500] 9
Finished game 10 (SF-Master vs SF-Master): 1/2-1/2 {Draw by insufficient mating material}
Score of SF-Master vs SF-Master: 0 - 0 - 10  [0.500] 10
ELO difference: 0
Finished match
All games finished as draw.

And now?
Jörg Oster
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hgm
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Re: fortress_draw_rule

Post by hgm »

I don't think it is possible to switch off the 50-move rule in Stockfish, is it? You can only switch off the 50-move rule in (Syzygy) tablebase probing, but it will always apply the fifty-move rule during search.
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Lyudmil Tsvetkov
Posts: 6052
Joined: Tue Jun 12, 2012 12:41 pm

Re: fortress_draw_rule

Post by Lyudmil Tsvetkov »

Joerg Oster wrote:
Lyudmil Tsvetkov wrote:
hgm wrote:Well, Duncan already posted that it is a mate in 31. So what else do you need to make yourself look foolish?
getting a reply from Duncan, and asking Milos the same thing, to acknowledge SF is able to mate easily, are 2 different things.

besides, I did not ask if it is mate, but whether SF is able to deliver the mate without tbs. also 2 different things.

sometimes people are also in a hurry and post, before reading the whole thread.

the point is, if SF is able to mate below:

[d]K5Q1/8/8/8/5bb1/6k1/8/8 w - - 0 1

why adjudicate draw? why on Earth?

that is the real question, and not whether I have posted a mate shorter than 50 instead of a longer one. I guess everyone understands that.
OK, I did you the favor.
Here is the result of a self-match, 10 games, tc=20+0.2, no EGTBs:

Code: Select all

Started game 1 of 10 (SF-Master vs SF-Master)
Started game 2 of 10 (SF-Master vs SF-Master)
Started game 3 of 10 (SF-Master vs SF-Master)
Finished game 1 (SF-Master vs SF-Master): 1/2-1/2 {Draw by fifty moves rule}
Score of SF-Master vs SF-Master: 0 - 0 - 1  [0.500] 1
Started game 4 of 10 (SF-Master vs SF-Master)
Finished game 3 (SF-Master vs SF-Master): 1/2-1/2 {Draw by fifty moves rule}
Score of SF-Master vs SF-Master: 0 - 0 - 2  [0.500] 2
ELO difference: 0
Started game 5 of 10 (SF-Master vs SF-Master)
Finished game 2 (SF-Master vs SF-Master): 1/2-1/2 {Draw by fifty moves rule}
Score of SF-Master vs SF-Master: 0 - 0 - 3  [0.500] 3
Started game 6 of 10 (SF-Master vs SF-Master)
Finished game 5 (SF-Master vs SF-Master): 1/2-1/2 {Draw by fifty moves rule}
Score of SF-Master vs SF-Master: 0 - 0 - 4  [0.500] 4
ELO difference: 0
Started game 7 of 10 (SF-Master vs SF-Master)
Finished game 6 (SF-Master vs SF-Master): 1/2-1/2 {Draw by fifty moves rule}
Score of SF-Master vs SF-Master: 0 - 0 - 5  [0.500] 5
Started game 8 of 10 (SF-Master vs SF-Master)
Finished game 4 (SF-Master vs SF-Master): 1/2-1/2 {Draw by fifty moves rule}
Score of SF-Master vs SF-Master: 0 - 0 - 6  [0.500] 6
ELO difference: 0
Started game 9 of 10 (SF-Master vs SF-Master)
Finished game 8 (SF-Master vs SF-Master): 1/2-1/2 {Draw by fifty moves rule}
Score of SF-Master vs SF-Master: 0 - 0 - 7  [0.500] 7
Started game 10 of 10 (SF-Master vs SF-Master)
Finished game 7 (SF-Master vs SF-Master): 1/2-1/2 {Draw by fifty moves rule}
Score of SF-Master vs SF-Master: 0 - 0 - 8  [0.500] 8
ELO difference: 0
Finished game 9 (SF-Master vs SF-Master): 1/2-1/2 {Draw by fifty moves rule}
Score of SF-Master vs SF-Master: 0 - 0 - 9  [0.500] 9
Finished game 10 (SF-Master vs SF-Master): 1/2-1/2 {Draw by insufficient mating material}
Score of SF-Master vs SF-Master: 0 - 0 - 10  [0.500] 10
ELO difference: 0
Finished match
All games finished as draw.

And now?
9 games finished with 50-moves rule, 1 with insufficient material.
so you have 50-moves set on, while I asked for 50-moves rule disabled, whether in code or possibly by some GUI.

besides, I asked for blitz games (blitz=5 min + increment)

this is a complex position, you can not expect to win in 20 seconds.
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Joerg Oster
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Location: Germany

Re: fortress_draw_rule

Post by Joerg Oster »

hgm wrote:I don't think it is possible to switch off the 50-move rule in Stockfish, is it? You can only switch off the 50-move rule in (Syzygy) tablebase probing, but it will always apply the fifty-move rule during search.
Indeed!
But even that wouldn't be sufficient.
It would also be necessary to tell cutechess-cli to not obey the rules of chess and not adjudicate draws by the 50-move rule.
Jörg Oster
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Lyudmil Tsvetkov
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Re: fortress_draw_rule

Post by Lyudmil Tsvetkov »

hgm wrote:I don't think it is possible to switch off the 50-move rule in Stockfish, is it? You can only switch off the 50-move rule in (Syzygy) tablebase probing, but it will always apply the fifty-move rule during search.
Joerg, if you have time, why do not you change 50-moves counter in SF to 200 or 300, and then recompile?

or is there a solution with a GUI?
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Lyudmil Tsvetkov
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Re: fortress_draw_rule

Post by Lyudmil Tsvetkov »

Evert wrote:
Lyudmil Tsvetkov wrote: [d]K5Q1/8/8/8/5bb1/6k1/8/8 w - - 0 1

this already should be tbs win in more than 50.

is SF able to deliver mate in blitz mode without tbs?
The position is a cursed win, so not against optimal defence. Against sub-optimal defence? Maybe, but who cares?
optimal defence = 50-moves rule on.

an even more optimal defence would be 20-moves rule on, but then there will be almost no checkmates.
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hgm
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Re: fortress_draw_rule

Post by hgm »

Joerg Oster wrote:Indeed!
But even that wouldn't be sufficient.
It would also be necessary to tell cutechess-cli to not obey the rules of chess and not adjudicate draws by the 50-move rule.
Actually the rules of Chess do not stipulate this as a mandatory draw, but just allows the players to claim one. So from the GUI point of view it is an adjudication. I WinBoard/XBoard you can specify the number of moves after which such an adjudication would be made, or switch it of altogether by specifying 0.

Of course there always is the risk that Polyglot would feel the need to claim a draw on behalf of the engine. But you could always use UCI2WB instead, which certainly would not do that.
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Lyudmil Tsvetkov
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Re: fortress_draw_rule

Post by Lyudmil Tsvetkov »

hgm wrote:That is not the position you asked about, which was a mate in 31. It seems you are back to the TCEC position.

Of course Stockfish cannot win that,.with or without EGT (against good defense). Or anyone else,for that matter. Because it is a theoretical draw.
and from my experience, top engines very easily solve similar simple positions; if SF sees the shorter win in 30 moves, certainly it will also see the bit longer one in 60 or so moves, it just needs more time.

problem is, how to disable 50-moves in SF and the GUI?
certainly someone has experience.
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hgm
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Re: fortress_draw_rule

Post by hgm »

Lyudmil Tsvetkov wrote:optimal defence = 50-moves rule on.
Optimizing defense does not constitute picking the rules. It is true that what is optimal depends on the rules; delaying the mate by an early sacrifice that resets the ply counter so that the mate, even though delayed, falls within the 50-move limit would obviously be stupid if a 50-move rule is in effect, while it is the only concern when it is not.

But it is easy enough to play Stockfish against either a Gaviota(=DTM)-using opponent as well as a Syzygy(=DTZ) using opponent.
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hgm
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Re: fortress_draw_rule

Post by hgm »

Lyudmil Tsvetkov wrote:problem is, how to disable 50-moves in SF and the GUI?
certainly someone has experience.
Well, as being said, it would require modification of Stockfish to play this Chess variant.

I would not recommend anyone to waste his time on that, though. We can just assume for the sake of argument that such a modified Stockfish easily finds a mate in 60. Like the modified version of Fairy-Max that I made easily finds the forced mate in 5 in this position:
[d]k7/8/1PK5/8/8/8/8/8 w
(Actually an unmodified version finds a mate in 3 here;for you to guess how to achieve that.) :lol:
And Sjeng finds an easy win for white in this position:
[d]7q/8/5k2/8/8/4K3/8/8 w
So what? By modifying/wrecking an engine you could make anything happen. Everything you said so far would still remain meaningless babble.
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