Stockfish Internals

[whittenizer]

Hi all,

I'm sifting through the source code for Stockfish, and trying to understand some of the array definitions. The RMult[64], BMult[64], RShift[64], and BShift[64] specifically. How are the values generated. Are they random? Not sure what each value represents. Let's take the first value for:

RMult[64] = {0xD7445CDEC88002C0ULL, ...

What is this value really telling me? I mean I can see how RMult is being used in other places in the code but I'd like to know why these specific values are used.

Thanks so much.

[Edmund]

You should read this article:
http://chessprogramming.wikispaces.com/Magic+Bitboards

[zamar]

Hi all,

I'm sifting through the source code for Stockfish, and trying to understand some of the array definitions. The RMult[64], BMult[64], RShift[64], and BShift[64] specifically. How are the values generated. Are they random? Not sure what each value represents. Let's take the first value for:

RMult[64] = {0xD7445CDEC88002C0ULL, ...

What is this value really telling me? I mean I can see how RMult is being used in other places in the code but I'd like to know why these specific values are used.

Thanks so much.

http://chessprogramming.wikispaces.com/ ... for+Magics by Tord Romstad