Author: Artem Pyatakov
Date: 21:55:37 04/01/04
Go up one level in this thread
>You need more than the attack tables. You need counts of attacks by piece type
>for every square.
Yes, I have a bit vector for every square that indicates every piece that is
attacking the square (not including the xrays, unfortunately). Sorry, attack
table was the wrong terminology.
>The strongest attack is a pawn attack. If you have 2 white pawn attacks and one
>black pawn attack, the square is won by white no matter what other pieces attack
>it (of course if you move one of the pawns to the square then the pawn attacks
>decreases by one).
>
>So do this for every square under attack:
>(white pawn attacks) - (black pawn attacks) {if zero, you are concerned about}
>(white piece attacks) - (black piece attacks) {knights and bishops}
>(white rook attacks) - (black rook attacks)
>(white queen attacks) - (black queen attacks)
>(white king attacks) - (black king attacks)
>
>And the same for pins (you will want to track the pinned pieces and xrays)
>
>If you track it for not only the attacked pieces but also the attacked squares,
>then you can know if an empty square is safe to step on for a given piece type.
I guess I need some time/more explanation to understand this, since I have not
seen anything like this when I was writing my program. Any more detailed
description of this? I understand the calculation you are performing (I think),
but I don't understand what their goal is. Is it only to check if a square is
safe to step on? What about the other important reason for qsearch, where for
instance I just did a capture of the opponent piece and I need to know if I will
be recaptured... Or are you saying you check that the same way? Hmm, perhaps
that makes sense... Am I thinking about this correctly? Is this really the only
reason qsearch exists? Hmmm, why don't more people then replace the qsearch with
an attack vector table and a simple static evaluation phase?
Does anybody actually use this idea in this manner. Any engines? Perhaps
Vincent??? I know he has all the attack information you talk about...
Thanks again.
Artem
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