[HN Gopher] Positions chess engines don't understand
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Positions chess engines don't understand
Author : diplodocusaur
Score : 51 points
Date : 2021-05-17 21:48 UTC (1 hours ago)
(HTM) web link (www.chess.com)
(TXT) w3m dump (www.chess.com)
| dwohnitmok wrote:
| Does anybody know if advanced chess/centaur chess (chess play
| where a human uses a computer for assistance) is still a
| thing/whether a human+computer combo is a meaningful improvement
| these days (i.e. last couple of years) over just a computer.
|
| I can't find any recent advanced chess tournaments and though I
| see quotes of people saying that the combo is stronger than a
| computer alone, I haven't found any recent examples of a top tier
| engine by itself losing to a human + engine (e.g. Stockfish +
| human vs Stockfish).
| edouard-harris wrote:
| Fully automated engines are now probably even with centaur
| teams.
|
| See, for example, this great write-up:
| https://www.gwern.net/Notes#advanced-chess-obituary
| dwohnitmok wrote:
| A quick glance doesn't seem to give conclusive evidence that
| pure engine play strictly dominates centaurs (the footnotes
| only have tournaments where centaurs still win, but these
| tournaments are also getting a bit old).
|
| The usual messaging I see around centaur-based styles such as
| certain correspondence chess tournaments is that you will
| lose if you just do "push-button play," that is just blindly
| do what the computer tells you to do.
|
| I'm curious if that's no longer true with the new crop of ML
| engines.
| edouard-harris wrote:
| You're absolutely right! Edited the gp from "strictly
| dominate" to "are probably even with". My memory of the
| piece was playing tricks on me.
|
| My best guess based on a rereading of the footnotes is that
| the performance ceiling for chess is probably low enough
| that it has been ~reached by both centaur teams and pure
| engines.
| perihelions wrote:
| Here's a particularly extreme example:
|
| https://old.reddit.com/r/chess/comments/ndz2lj/simple_mate_i...
|
| It's a mate-in-93 puzzle that's fairly accessible to humans,
| using abstract reasoning. But not chess engines. Comparing
| against the OP article, the main "technique"/"trick" is zugzwang
| (#7), but on a dramatic scale.
| TchoBeer wrote:
| I think there are some engines (Crystal is the one I'm thinking
| of) which do well in fortresses; these come at the cost of play
| strength.
| thaumasiotes wrote:
| Presumably the next step is a synthesizer which can choose the
| appropriate engine to delegate to based on its own reading of
| the board.
| senkora wrote:
| It seems dubious to show that engines are sometimes bad at
| evaluating positions by giving a position with three black
| bishops on black squares.
| awb wrote:
| There are other more realistic examples like the Nakamura game
| sacrificing 2 useless rooks to give the engine a false sense of
| winning. Then the engine sacrifices a valuable pawn to avoid a
| 50 move draw. Turn out the pawn was much more valuable than the
| 2 rooks in the particular closed position and Nakamura goes on
| to win. Basically, the only way to beat an engine is to try to
| create an unusual situation that the AI hasn't practiced
| before.
|
| But as others other out, AI suffers when it doesn't have enough
| experience in a particular situation. So, the author is really
| just pointing out the extreme edge cases AI hasn't mastered
| yet. But over time and getting these examples into the training
| process there's no reason to believe that the AI couldn't learn
| these situations as well.
| [deleted]
| diplodocusaur wrote:
| are you assuming the engine got there by itself in the first
| place?
| lmilcin wrote:
| While unheard of, this is not illegal.
|
| You could theoretically convert two pawns to bishops and have
| three black bishops. Nobody would do that as it is usual to
| convert pawns to queens, but it is within the rules for you to
| choose.
|
| So if you plan to write chess engine it would be pretty stupid
| of you to not prepare it to face multiple black bishops. If I
| knew that it would give me a lot of advantage.
| ioseph wrote:
| I could imagine such a move making sense with the king on the
| backline such that promotion to queen would trigger a
| stalemate
| tialaramex wrote:
| Underpromotions are one of those "toy problem" things. A
| human might finish a whole professional career having never
| once promoted a pawn to anything but a queen, but in
| theoretical problem positions - like the one you're talking
| about - they happen "all the time" because it's a fun twist.
|
| So it's understandable for a machine not to even bother
| modelling these weird cases I think.
| matsemann wrote:
| When watching the WC games, I've seen it happen that a move
| wasn't considered as a top move by the engine, but once played
| the engine realizes it's actually crushing. Something about the
| heuristics used to prune the vast search space can make it miss
| sacrifices or seemingly sub-optimal moves that temporarily
| weakens the perceived position but has a huge payoff in the end.
| But humans find them. Of course, given enough time and depth the
| engine will eventually circle back and try the move. But it has
| no intuition.
|
| Also, an engine without an endgame tablebase can be pretty
| stupid. There are certain rules one can deduct when there are few
| pieces left, but a min/max engine will search forever, not
| knowing the patterns.
| thaumasiotes wrote:
| > I've seen it happen that a move wasn't considered as a top
| move by the engine, but once played the engine realizes it's
| actually crushing. Something about the heuristics used to prune
| the vast search space can make it miss sacrifices or seemingly
| sub-optimal moves that temporarily weakens the perceived
| position but has a huge payoff in the end. But humans find
| them.
|
| Just to observe, humans display exactly the same phenomenon of
| ignoring a move before it's made while still being able to
| realize, after it's made, that it was very strong and ignoring
| it was a mistake.
| bottled_poe wrote:
| No intuition? What is intuition other than a position
| assessment heuristic? Game-tree AI must limit the game tree
| search at some depth. In order to exploit this, the opponent
| would need to identify the position strength at a deeper level
| than the AI's search depth, which seems unlikely.
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