Computer Chess Club Archives




Subject: Re: Artificial Intelligence in Computer Chess

Author: Anthony Cozzie

Date: 04:57:37 03/29/04

Go up one level in this thread

On March 29, 2004 at 06:05:20, Vasik Rajlich wrote:

>On March 28, 2004 at 22:44:27, Artem Pyatakov wrote:
>>>I think you and Steven both enjoy thumbing your noses at the "conventional,
>>>hat-trick, alpha-beta seachers".  I am not quite sure why, but whatever floats
>>>your boat . . .
>>Well, I've explained my objections to it. Don't get me wrong, I am one of those
>>people - I have written a program that uses all of the tricks I criticize. But
>>my objection to it is that a lot of these tricks are not beneficial for research
>>in related fields - even close ones like playing other games, and thus it would
>>be nice to change philosophies. It would also be much more elegant to be able to
>>have computers learn the tricks themselves, don't you think?
>Hi Artem,
>it's great that you have lots of ideas. Lots of people here have lots of ideas.
>The questions eventually are, what do you hope to accomplish, and how can you
>fit your ideas into a framework to help you accomplish it.
>This is a constant process for example at the level of evaluation. I constantly
>find positions I'd like my engine to evaluate differently. Usually, it's not
>hard to find some way to try to capture it. However, I expect my evaluation to
>have a certain level of speed and simplicity, and changing this would mean
>changing the whole framework. (Ie slower evaluation means you should do things
>differently in search, etc.) I won't, for example, look for exact patterns
>inside my evaluation - that's outside its bounds. So, often, the conclusion is
>that the idea has no sensible implementation.
>Re. alpha-beta, I have lots of ideas for how to expand it into something more
>human-like. For example, yesterday I played a chess game for my club in which I
>sacrificed a piece for an attack, and in a number of positions the move Ke1-d2
>deserved serious consideration, to avoid later checks on the e-file.
>Furthermore, Ke1-d2 was better than castling queenside (which was still
>allowed), because the king should support a later Re1. After the game, I started
>thinking: how can you avoid reducing a move like Ke1-d2? This is exactly the
>sort of move which makes selective searching so hard. In most positions, of
>course, it's about the last move to consider when you are trying to justify a
>sacrificial attack - especially when the safer queenside castling is possible.
>A human considers this move because later in the tree, checks along the e-file
>play a role. How would this look inside the alpha-beta framework? Maybe
>something like: if one side fails high in some "pv-like" (ok already MTD (f) has
>some issues ...) variation by giving a check, then "pay special attention to"
>all king moves earlier in the search. Unfortunately, this simply doesn't fit
>inside alpha-beta. In MTD (f) you may research based on the score, but I don't
>know of any alpha-beta framework inside which you research based on any type of
>new information other than the score.
>So, as so often, you ask: do I expand/scrap the framework (in this case,
>alpha-beta), or does this idea go into the scrap pile (or revisit later list)?
>If your goal is something which works, you'll probably unfortunately find that a
>lot of your more interesting ideas fall into the second category ;-)
>Anyway, good luck with the project.

So many good ideas have to be discarded simply because they won't work.

From one of David Eddings' books.


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