Cursed win at TCEC

[Lyudmil Tsvetkov]

Actually, if you check TCEC page at facebook, Anton says he's considering changing the score. Quite likely he's also reading our discussion.

That's good news. In that post, he mentions: "Both engine authors have submitted their opinion to the TCEC team." Hearkening back to my question some pages ago, I'm glad to hear the devs did indeed write to the organizer, with presumably even the SF team in favor of it being a draw (yes?).

what else would the SF team say, they are all chivalrous, you know.

[Evert]

[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?

[hgm]

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.

[whereagles]

SF is able to deliver mate on its own in such positions, so why deprive it of a well-deserved win?

Because, as others mentioned, the engines played in the assumption that the 50-moves rule was in effect. If Houdini was aware that cursed wins would indeed be scored as wins, it might have chosen other moves that may have led to a draw (or not..). Since we'll never know that, an adjudication is the solutions. In fact, this is what adjudication in sports is for.

Note also that people have checked some posts ago that Houdini did in fact had other drawish moves. It did not play those because engine efficiency requires it to opt for a drawish move as soon it finds one. And of course, a drawish TB hit is the fastest way to do it, so other draw possibilities are automatically pruned.

As I mentioned in my last post, I agree that cursed wins should be scored as wins, but only in engine tournaments where all engines have access to tablebases that can disable the 50-moves rule (you can also make a pretty good case for that in correspondence matches).

This is not the case of TCEC, because it has dozens of entrant engines and not all comply to that requirement. TCEC is all about quick access to the best live chess there is: one-click universal access, LTC games, all of the top engines, live chat flaming.. (lol). It would be weird to have different rules depending on whether engines have "50-moves /OFF" tablebase switches or not, so I think Anton should just adjust cutechess to score cursed wins as draws and otherwise leave TCEC as it is.

As to human games, well 200 moves (as you mentioned in the other thread, which seems to be broken for me at the moment) is far too much, even in special positions. That would lead to the dominant player to keep on playing drawn positions for a long time, hoping that his opponent messes up (he risks nothing). In some mind sports this sort of futile play is considered unethical and is liable to disciplinary sanctions. I agree with that view because it does not contribute to the promotion of the sport.

[Lyudmil Tsvetkov]

[d]8/4n3/4k3/8/8/4K1B1/2B5/8 w - - 0 1

why instruct the engine above position is a draw, when SF finds mate very quickly even at bullet?

I'm not sure what point you think you're making?
The position is apparently mate in 43 moves (starting with 1. Bb3+), so the 50 move rule is irrelevant even if the knight is not captured (which I haven't checked). Source: Nalimov tables from http://www.k4it.de/?topic=egtb&lang=en.

Yes, one side to this discussion is rather unwilling to understand the stuff he's talking about.

https://syzygy-tables.info/?fen=8/4n3/4 ... _w_-_-_0_1

DTZ=59, so white can force a mate or winning capture in under 30 moves.

If this were impossible to win within the 50-move rule, SF would be expected not to find a mate in the first place. After all, SF knows about and accepts the 50-move rule.

I can not go check each and every tbs position whether is a longer or shorter than 50 mate. The general rule say BB vs N 66 moves longest mate, there are shorter mates of course. the point was to demonstrate that SF is able to deliver mate on its own in such positions, so why deprive it of a well-deserved win?

do not have quick access as well as the time to check tbs now, I hope you will help out with this, but here is a position I presume is longer than 50 mate:

[d]2kb4/1b6/8/8/3Q4/8/8/4K3 w - - 0 1

actually, a variation of the TCEC game

I presume SF will be able to deliver mate on its own above at blitz TC, will it not?

Is somebody able to check this?

Why don't you check yourself?

Here https://syzygy-tables.info/ you can insert the FEN of the position you want to know,
and you get all information you need.

You can even download the full PGN of the main dtz winning line.

Code: Select all

[Event ""]
[Site "http://syzygy-tables.info/?fen=2kb4/1b6/8/8/3Q4/8/8/4K3_w_-_-_0_1"]
[Date "2016.11.25"]
[White "Syzygy"]
[Black "Syzygy"]
[Result "1-0"]
[SetUp "1"]
[FEN "2kb4/1b6/8/8/3Q4/8/8/4K3 w - - 0 1"]
[Annotator "syzygy-tables.info"]

{ DTZ 43 } 1. Qd6 Bc7 2. Qe6+ Kd8 3. Kd2 Bc8 4. Qc6 Bd7 5. Qf6+ Kc8 6. Kc3 Kb7 7. Kc4 Bb6 8. Kd5 Bb5 9. Qe7+ Ka6 10. Kd6 Ba7 11. Kc7 Bb6+ 12. Kb8 Bc4 13. Qb4 Bb5 14. Qa3+ Ba5 15. Qb3 Bb6 16. Qa2+ Ba5 17. Qd5 Bb4 18. Qb7+ Ka5 19. Qa7+ Ba6 20. Kc7 Kb5 21. Qb6+ Ka4 22. Qxa6+ { KQvKB with DTZ -16 } 22... Kb3 23. Qd3+ Kb2 24. Kb6 Bc3 25. Kb5 Kb3 26. Kc5 Kb2 27. Kc4 Ba5 28. Qb3+ Ka1 29. Qa3+ Kb1 30. Qxa5 { KQvK with DTZ -6 } 30... Kb2 31. Qd2+ Ka1 32. Kb3 Kb1 33. Qb2# { Checkmate } 1-0

thanks Joerg.

because in that case there will be no one to ask questions and suggest new rules...

I have another request for you or anyone else capable of helping:

[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?

White is winning with DTZ 117, so, for once, I picked a longer than 50 mate.

question is, in a SF vs SF match, 50-moves rule switched off, is SF able to deliver mate in blitz mode, and within how many moves?

[Joerg Oster]

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?

[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.

[Lyudmil Tsvetkov]

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.

[Joerg Oster]

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.

[Lyudmil Tsvetkov]

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?