What's up with this endgame?

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todd
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Re: What's up with this endgame?

Post by todd » Wed Jul 24, 2019 4:00 pm

Ovyron wrote:
Wed Jul 24, 2019 7:49 am
The lesson for me here was about endgames with same-colored bishops being won for one side (no matter what engines say)
Perhaps you have already realized this, but this non-drawish tendency is specifically about same-color bishop endgames with weak pawns (usually one weak pawn isn't enough) unable to move.

Same-color bishop endgames aside from these cases, in general, have a more drawish tendency than most types of endgames.

todd
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Re: What's up with this endgame?

Post by todd » Wed Jul 24, 2019 4:03 pm

MikeB wrote:
Wed Jul 24, 2019 7:30 am
I have looked at this some more, and I don't see the loss until you played 53 ...gxf4. That is the only point where I am certain that you are lost. But it's clearly possible that my hardware and software is simply not adequate for this game. I think very few people would have access to computer that can find the winning line if you played something other than gxf4. Well, time for you to start that new unbeaten streak!
A good human player will try the obvious (to those who have studied bishop endgames at all) plan with the engine turned on and quickly stumble on the win, though. They have probably been aiming for it for the whole game once the pawn structure had been established.

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Ovyron
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Re: What's up with this endgame?

Post by Ovyron » Wed Jul 24, 2019 4:36 pm

todd wrote:
Wed Jul 24, 2019 4:00 pm
Perhaps you have already realized this, but this non-drawish tendency is specifically about same-color bishop endgames with weak pawns (usually one weak pawn isn't enough) unable to move.
"Weak pawns" is a concept I do not have, so yeah, I probably lost this game because of inferior human chess knowledge.
Great spirits have always encountered violent opposition from mediocre minds.

todd
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Re: What's up with this endgame?

Post by todd » Wed Jul 24, 2019 5:32 pm

Ovyron wrote:
Wed Jul 24, 2019 4:36 pm
"Weak pawns" is a concept I do not have, so yeah, I probably lost this game because of inferior human chess knowledge.
Pawn that cannot be protected by another pawn. It's worse if that pawn can't move.

Here white has two weak pawns on d4 and f4 and loses.



Let's move the pawns on the f-file up a couple of ranks. Now white has only one weak pawn on d4. There is no reason white will ever have to move the king from d3, because there isn't a second pawn that will need to be protected. So this is an easy draw.




In your game, d5 was one fixed weak pawn. g6-f5 is a little trickier - g6 is on the wrong color - it's attackable, but it can move. But if it does move, then f5 is a blocked and weak pawn. So no matter what, there is a second target for white.

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Ovyron
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Re: What's up with this endgame?

Post by Ovyron » Fri Jul 26, 2019 3:42 am

Thanks for explaining Todd. I have always defeated "engine slaves", people that just go and ask engines for a move and play them, so I can predict their moves and figure out what would defeat them (I'm currently beating a high rated player like that, just because when copying the engine's move, he moved the wrong Knight...) But maybe I can beat them with such human chess principles as well.

I figure out a chess engine shouldn't need 6men tablebases and depth 78 to see that the position in the OP is lost, but that someone with the right knowledge would have realized black would have been crazy to allow such a position to be reached.
Great spirits have always encountered violent opposition from mediocre minds.

Uri Blass
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Re: What's up with this endgame?

Post by Uri Blass » Fri Jul 26, 2019 3:49 am

I do not think that it is possible to predict engine's moves to plan a win in advance because they are not deterministic and change their mind.
I doubt if you can beat stockfish at 1 hour per move with no book most of the times.

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Ovyron
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Re: What's up with this endgame?

Post by Ovyron » Fri Jul 26, 2019 4:06 am

It's surprisingly easy in practice. The reason I'm still on a 4CPU from 10 years ago is because, as it turns out, it's also surprisingly easy to predict moves that need high depth to be found.

Not only that, it's also surprisingly easy to predict people's opening moves. At one point I built a big database with all the corr chess games I could find (big mistake! it's full of garbage moves by people not using engines, but I didn't know better), then I had this opponent that played the most played move of the db three moves in a row. So I extrapolated it and managed to predict his next 20 moves, and managed to get the most advantageous position I could once out of book.

In the end I predicted all his moves and when I couldn't, they were worse moves than what I predicted. Unfortunately, I had played a drawish opening (at this point I was scared of higher rated people, and played more safely than now) so not even knowing what he was going to play was enough to win. The draw wideness of chess is indeed big.

But this is a common thing, either you predict their move, or they play something worse than what you predicted. Last week I was surprised by 2 moves, by someone that seemed to want a draw as white :shock:
Great spirits have always encountered violent opposition from mediocre minds.

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