maps of strong/weak square

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elcabesa
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maps of strong/weak square

Post by elcabesa »

I was thinking about adding a map of strong and weak point of a position and trying to use them for evalutation or for something like move ordering ( for example by giving high priority to move attacking a weak square).
Has anyone tried something like that in the past? Do you think this could be useful?
bob
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Re: maps of strong/weak square

Post by bob »

elcabesa wrote:I was thinking about adding a map of strong and weak point of a position and trying to use them for evalutation or for something like move ordering ( for example by giving high priority to move attacking a weak square).
Has anyone tried something like that in the past? Do you think this could be useful?
I did something similar in Cray Blitz. But it can be pretty expensive to sum up all the values of the squares you attack. On the Cray, a vector operation would do this quite nicely (gather type vector access). On scalar machines, it proved to be too slow as loops inside the eval are expensive when done so many times.
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mhull
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Re: maps of strong/weak square

Post by mhull »

bob wrote:
elcabesa wrote:I was thinking about adding a map of strong and weak point of a position and trying to use them for evalutation or for something like move ordering ( for example by giving high priority to move attacking a weak square).
Has anyone tried something like that in the past? Do you think this could be useful?
I did something similar in Cray Blitz. But it can be pretty expensive to sum up all the values of the squares you attack. On the Cray, a vector operation would do this quite nicely (gather type vector access). On scalar machines, it proved to be too slow as loops inside the eval are expensive when done so many times.
Is it safe to assume the vector operations on the cray were more capable than the SIMD operations on microchips, and vastly more convenient to use than GPU vector operations? Or, could these facilities be utilized for such functions?
Matthew Hull
elcabesa
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Re: maps of strong/weak square

Post by elcabesa »

looking int the code trying to understand how and whether to add maps of strong weak square, I found a bug into my code :)
PK
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Re: maps of strong/weak square

Post by PK »

You might try using just a map of squares controlled by pawns, and see if it helps.
Lyudmil Tsvetkov
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Re: maps of strong/weak square

Post by Lyudmil Tsvetkov »

elcabesa wrote:I was thinking about adding a map of strong and weak point of a position and trying to use them for evalutation or for something like move ordering ( for example by giving high priority to move attacking a weak square).
Has anyone tried something like that in the past? Do you think this could be useful?
In my strictly personal chess experience, all weak squares (undefended by pawns) on the 3rd rank are a significant handicap, and very long-span at that, because such squares do not disappear. Weak squares on the 4th rank might be worth just a very small fraction of the penalty for squares on the 3rd. And squares on the 3rd rank, part of the king shelter, might be even more dangerous to allow.

Considering just control of minor pieces over weak squares might be a good idea.

Strictly chess-wise, the more weak squares on the 3rd rank you have, the worse you are.