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Tactical search

Posted: Sat Jun 13, 2020 5:45 pm
by Cardoso
Hi,
I'm thinking adding one or more threads dedicated to a tactical search.
Probably I will also add another thread for mate search but this is another issue.
What are the main ideas to take into consideration when implementing a tactical mode?

thanks,
Alvaro

Re: Tactical search

Posted: Sat Jun 13, 2020 7:21 pm
by Dann Corbit
Cardoso wrote: Sat Jun 13, 2020 5:45 pm Hi,
I'm thinking adding one or more threads dedicated to a tactical search.
Probably I will also add another thread for mate search but this is another issue.
What are the main ideas to take into consideration when implementing a tactical mode?
Houdini did something very much like your idea.
I suggest you might want to look at the repository found listed in the fishcooking forum.

Re: Tactical search

Posted: Mon Jun 15, 2020 2:31 pm
by Rebel
Cardoso wrote: Sat Jun 13, 2020 5:45 pm Hi,
I'm thinking adding one or more threads dedicated to a tactical search.
Probably I will also add another thread for mate search but this is another issue.
What are the main ideas to take into consideration when implementing a tactical mode?

thanks,
Alvaro
Out of pure curisoity I once at the end of eval replaced the score with the incremental PST value (thus counting wood mainly) and noticed the search came 1.5 - 2 ply deeper. Doing that at the beginning increased the NPS.

Re: Tactical search

Posted: Tue Jun 16, 2020 3:33 am
by Cardoso
Rebel wrote: Mon Jun 15, 2020 2:31 pm
Cardoso wrote: Sat Jun 13, 2020 5:45 pm Hi,
I'm thinking adding one or more threads dedicated to a tactical search.
Probably I will also add another thread for mate search but this is another issue.
What are the main ideas to take into consideration when implementing a tactical mode?

thanks,
Alvaro
Out of pure curisoity I once at the end of eval replaced the score with the incremental PST value (thus counting wood mainly) and noticed the search came 1.5 - 2 ply deeper. Doing that at the beginning increased the NPS.
Aside the NPS increase, probably is a similar effect to the code below from Stockfish evaluation function that forces evaluation values being multiples of 16 (grain size).

Code: Select all

// Evaluation grain
    v = (v / 16) * 16;