mmt Vs. Ovyron (G4 D5 BG2)

Discussion of computer chess matches and engine tournaments.

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Ovyron
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Re: mmt Vs. Ovyron (G4 D5 BG2)

Post by Ovyron »

Not wanting to answer simple questions is not the same as being unable to answer them. I'll explain the reason of the secrecy after I'm done, and it'll make sense by then.
zullil
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Re: mmt Vs. Ovyron (G4 D5 BG2)

Post by zullil »

Ovyron wrote: Tue Feb 18, 2020 5:24 pm Not wanting to answer simple questions is not the same as being unable to answer them. I'll explain the reason of the secrecy after I'm done, and it'll make sense by then.
OK. I hope I live long enough to see you finish...
jp
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Re: mmt Vs. Ovyron (G4 D5 BG2)

Post by jp »

Ovyron wrote: Tue Feb 18, 2020 5:12 pm
jp wrote: Tue Feb 18, 2020 4:18 pm Well, the comment on that bit of code (//....) suggests ...
Yes, if Stockfish shows a mate in N, then it can guarantee maximality.

UNLESS THERE'S A BUG

Ironically, a few days after my post it was found that VALUE_MATE_IN_MAX_PLY had a bug (which is used on the relevant code), so who knows ...
Well, if there's no bug and if the coder who wrote that comment knows what "proved" and "unproved" mean, it would not be "maximality"; it would just be an upper bound on mate. "Maximality" would be the longest possible mate, i.e. the greatest number of moves that don't give up the win (e.g. through the 50-move rule).


I think we can and should run simple tests on SF mate announcements. It's a matter of coming up with the right test positions.
Last edited by jp on Wed Feb 19, 2020 12:40 am, edited 1 time in total.
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Ovyron
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Re: mmt Vs. Ovyron (G4 D5 BG2)

Post by Ovyron »

It's maximal assuming best opponent defense.
jp
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Re: mmt Vs. Ovyron (G4 D5 BG2)

Post by jp »

Please let's not discuss wording further, but it's not that. "Maximal" would be the attacking side dragging it out. e.g. Leela queening 8 pawns amid shuffling its king back and forth against a weak opponent.
zullil
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Re: mmt Vs. Ovyron (G4 D5 BG2)

Post by zullil »

jp wrote: Wed Feb 19, 2020 12:37 am
Ovyron wrote: Tue Feb 18, 2020 5:12 pm
jp wrote: Tue Feb 18, 2020 4:18 pm Well, the comment on that bit of code (//....) suggests ...
Yes, if Stockfish shows a mate in N, then it can guarantee maximality.

UNLESS THERE'S A BUG

Ironically, a few days after my post it was found that VALUE_MATE_IN_MAX_PLY had a bug (which is used on the relevant code), so who knows ...
Well, if there's no bug and if the coder who wrote that comment knows what "proved" and "unproved" mean, it would not be "maximality"; it would just be an upper bound on mate. "Maximality" would be the longest possible mate, i.e. the greatest number of moves that don't give up the win (e.g. through the 50-move rule).


I think we can and should run simple tests on SF mate announcements. It's a matter of coming up with the right test positions.
Maybe just ask politely at https://groups.google.com/forum/?nomobi ... ishcooking ?
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Ovyron
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Re: mmt Vs. Ovyron (G4 D5 BG2)

Post by Ovyron »

"This is the maximum number of moves it'd take me to beat an opponent that defends perfectly, as they're unable to delay mate further" is a maximal. The maximal of moves to mate by "fooling around" instead of playing best moves from your side ("the slowest mate") makes no sense to discuss, but at least Zenmastur didn't ask for that...

The optimal mate is the one that is both the minimal and maximal, the maximal keeps reducing until both met as more lines for the winning side are explored. The minimal is unknown until all attacks have been exhausted.
jp
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Re: mmt Vs. Ovyron (G4 D5 BG2)

Post by jp »

Please stop. It'll just end up going around in circles again. Just focus and solve the **** puzzle, so we can get games. I don't know why you post at all before you've solved it.
Last edited by jp on Wed Feb 19, 2020 1:00 am, edited 1 time in total.
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Ovyron
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Re: mmt Vs. Ovyron (G4 D5 BG2)

Post by Ovyron »

zullil wrote: Wed Feb 19, 2020 12:51 am Maybe just ask politely at https://groups.google.com/forum/?nomobi ... ishcooking ?
When people produce games to test the engine they automatically test for mate claims. You don't need to run any games, just look at mate claims by Stockfish in the PGN and see if at any point it has reported a mate score that was wrong (the defending side can delay mate.)

What jp is talking about has never been witnessed, I don't know from where this fear of a wrongly reported mate comes from.
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Ovyron
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Re: mmt Vs. Ovyron (G4 D5 BG2)

Post by Ovyron »

jp wrote: Wed Feb 19, 2020 12:58 am Please stop. Just solve the damn puzzle, so we can get games.
Be more polite, remember that I can request Zenmastur to hold our game privately so you don't get to see it :P