Search found 67 matches

by grant
Mon Sep 18, 2017 12:17 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Disproving the existence of some magics
Replies: 4
Views: 2166

Re: Disproving the existence of some magics

I am doubtful you will find a1 or h1 but good luck to you.

Grant
by grant
Mon Apr 20, 2015 3:30 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: A Combination
Replies: 6
Views: 1664

Re: A Combination

Yes nothing is for free, and those nasty details get me every time.
by grant
Mon Apr 20, 2015 2:30 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: A Combination
Replies: 6
Views: 1664

Re: A Combination

Gerd

I would, of course, check the diagonal for bishops/queens and if there are none there is no point running that piece of code.
This is a sample to demonstrate that while checking to see if you are in check (as you normally do) you can also return information on pinned pieces.

Grant
by grant
Mon Apr 20, 2015 8:58 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: A Combination
Replies: 6
Views: 1664

Re: A Combination

Hi Gerd I'll try to explain. Let's say we put a white king on A8 and a black bishop on H1. BishopMagic() returns the diagonal B7 to H1 which we 'and' with allOccupied. We use this in BishopPinMagic() to return check and pinned pieces information. If there's nothing inbetween king and bishop, BishopP...
by grant
Sun Apr 19, 2015 11:54 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: A Combination
Replies: 6
Views: 1664

A Combination

Hi I put up a post a few years ago about using magics to get a bitboard of pinned pieces, and the general concensus was that it was not worth the computational effort and extra lookups to get this information, as pinned pieces are rare. However, since we all have to determine whether or not we are i...
by grant
Tue May 24, 2011 1:55 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Magics
Replies: 27
Views: 10343

Re: Magics

Edmund I read the initial post in the other forum by Volker Annuss some time ago, and I decided to try for myself to reduce the table size as much as I could. This was my only goal. The post is headed "Fixed shift magics with 800KB lookup table". However, I found that a smaller table could be achiev...
by grant
Tue May 24, 2011 11:06 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Magics
Replies: 27
Views: 10343

Re: Magics

Hello Edmund

I think I'll need a translator because I didn't understand a word of what he wrote.

Grant
by grant
Mon May 23, 2011 11:58 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Magics
Replies: 27
Views: 10343

Re: Magics

Mdb just stands for "Magic DataBase"

Grant
by grant
Thu Apr 01, 2010 1:43 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Cache-friendier material index
Replies: 4
Views: 2422

Re: Cache-friendier material index

Hi HG I'm just a little bit puzzled by this. The number of material combinations for nWN + 3*nBN + 9*nWB + 27*nBB + 81*nWR + 243*nBR + 729*nWQ + 1458*nBQ + 2916*nWP + 26244*nBP is 236196 The number of material combinations for 2*243*nWR - (2*243-81)*nBR + (243+27+9)*nWB - (243+27)*nBB + (243+3)*nWN ...