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Subject: Re: A question about underpromotion danger

Author: Ricardo Gibert

Date: 14:32:51 08/04/99

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On August 04, 1999 at 16:30:38, Robert Hyatt wrote:

>On August 04, 1999 at 14:40:31, KarinsDad wrote:
>
>>On August 04, 1999 at 14:09:18, Bruce Moreland wrote:
>>
>>>
>>>On August 04, 1999 at 12:16:52, Dann Corbit wrote:
>>>
>>>>As a 'for instance':
>>>>
>>>>Suppose that on promotion, a program sees that it can promote to a knight
>>>>instead of a queen, and get a king fork, taking a bishop, followed by a queen
>>>>fork, taking the other bishop.  In such a case, it might evaluate:
>>>>   -pawn+knight+bishop+bishop+two_bishop_bonus+(minor positional goo)
>>>>verses
>>>>   -pawn+queen
>>>>and get something a fraction more valuable than a queen.  But down the road I
>>>>would rather have the queen than a knight and remove the two bishops.
>>>>
>>>>How do programs deal with this?
>>>
>>>You are really saying you'd rather have a queen against two bishops than be a
>>>knight up, right?
>>>
>>>bruce
>>
>>Actually, assuming an equal game, it is a preference of being up a queen for a
>>pawn as opposed to being up a knight and two bishops for a pawn.
>>
>>Of course, decisions like these are always based off of the actual position, but
>>here is a comment Kasparov made just the other day on Ponomariov - Al Modiakhi
>>in round 1 of the championship:
>>
>>"Looking at Ponomariov's 7.Be3 with 8.Bb6 I have sensed chess of the very
>>distant future. With my limited knowledge of the game I would consider 3 minor
>>pieces in such position much better than Queen+pawn".
>>
>>So, there are obviously positions where having 3 minors is better than having
>>the queen.
>>
>>KarinsDad :)
>
>
>I think that in almost _all_ cases, three minors pieces are better than a
>single queen.. and most games I have seen where this happens are wins for the
>three minors.  I don't like two minors and 3 pawns vs a queen however, unless
>maybe if the pawns are all on the 6th rank or farther along.  :)

I felt pretty sure about this too, but I analyzed with Jack Peters a particular
position and came away with idea that it was a lot closer than I thought and
that subjective factors have a big impact. I still prefer the 3 pieces, but now
I am more careful. The 3 pieces don't organize themselves very quickly, but the
Q is relatively much faster in this respect. It depends very much on the
position.

Related to this topic is R+P+P vs B+N. You have indicated that you set this as
equal. At first I thought this was a mistake, but then I thought about it and
this may be right for chess playing programs, since they are not sufficiently
effective in getting the rook into play. As a human, I use R+P < B+N < R+P+P. I
believe this is the "normal" evaluation. R+P+P = B+N is a practical choice for
computers. Of course subjective factors must be considered.



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