Search found 1747 matches

by Gerd Isenberg
Wed Jul 21, 2021 7:17 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Fortress detection?
Replies: 7
Views: 950

Re: Fortress detection?

fierz wrote:
Wed Jul 21, 2021 12:54 pm
,,,
Is there any way that such "shuffling-around" fortresses can be detected sensibly?

best regards
Martin
In Pawn endings maybe Blockage Detection?
See also Code of Chiron for Detection of Pawn Blockages by Ubaldo Andrea Farina.
by Gerd Isenberg
Wed Jul 21, 2021 6:46 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: 1k zx chess sources question
Replies: 13
Views: 1170

Re: 1k zx chess sources question

Hi guys, I have a few questions on 1k zx chess by David Horne: 1. 1K means 1K of RAM? 2. Were there any limitations on source code size? 3. Is it written in assembly because BASIC interpreter takes some RAM on it's own? 4. Are there any ports of 1k zx chess from assembly to whatever languages? I'm ...
by Gerd Isenberg
Tue Jul 20, 2021 3:59 pm
Forum: Computer Chess Club: General Topics
Topic: Summer time - how does your PC cooling solution perform?
Replies: 47
Views: 8425

Re: Summer time - how does your PC cooling solution perform?

... You seriously don't understand. Oh man. Ok, let me draw it for you one more time. You have a CPU that has certain TDP, or lets say maximum allowed power before it start throttling back. Lets say it's 120W. Now lets say you put a better cooler and it will allow you to 150W of maximum power consu...
by Gerd Isenberg
Thu Jul 08, 2021 11:50 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: What is the point of magic hashing over simply using masked occupancy as index ?
Replies: 9
Views: 1712

Re: What is the point of magic hashing over simply using masked occupancy as index ?

If I understand correctly, the method that you are comparing to magic hashing is pretty similar to what kindergarten bitboards do. I believe (I am not sure) that the reason why many people prefer magic bitboards is that the generation of the hash is faster than the stuff you need to do to shift the...
by Gerd Isenberg
Thu Jul 08, 2021 8:21 am
Forum: Computer Chess Club: General Topics
Topic: In memory of Guy Haworth
Replies: 3
Views: 762

Re: In memory of Guy Haworth

My condolences to his family and friends as well.
by Gerd Isenberg
Fri Jul 02, 2021 5:52 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: How can i improve my C# engine speed?
Replies: 58
Views: 7603

Re: How can i improve my C# engine speed?

visual studio points to this function call inside the evaluate to have heavy cpu impact: the function implementation: [MethodImpl(MethodImplOptions.AggressiveInlining)] public static byte GetLS1BIndex(ulong _bitboard) { return CountBits((_bitboard & (0 -_bitboard)) - 1); } [MethodImpl(MethodImplOpt...
by Gerd Isenberg
Sun Jun 06, 2021 7:48 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Futility Pruning and its Relation to Quiescence Search
Replies: 3
Views: 1453

Re: Futility Pruning and its Relation to Quiescence Search

With classical FP à la Heinz at frontier nodes (depth==1), you don't go into qsearch (this is matter of some razoring techniques) but you skip none tactical moves inside the move loop. See Ernst A. Heinz' Search with Extended Futility Pruning and Limited Razoring Code , futility pruning at frontier ...
by Gerd Isenberg
Fri Apr 23, 2021 3:33 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: I did some magic bitboard "science" and mostly learned not to worry about it
Replies: 16
Views: 8977

Re: I did some magic bitboard "science" and mostly learned not to worry about it

Here my newness to chess programming specifically shows. Is the usual approach to physically create the move list and explicitly order it? The above thing is why I jumped through some hoops and try to specifically avoid this by generating them on the fly where you again can make some use of the bit...
by Gerd Isenberg
Tue Apr 20, 2021 5:34 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: I did some magic bitboard "science" and mostly learned not to worry about it
Replies: 16
Views: 8977

Re: I did some magic bitboard "science" and mostly learned not to worry about it

A variation of the classical approach using x^(x-1) separation and pure calculation for orthogonal lines and tiny lookup for diagonals.
Very nice!
by Gerd Isenberg
Sun Mar 28, 2021 7:51 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Computers, Chess and Long-Range Planning, by Michail M. Botvinnik
Replies: 7
Views: 3012

Re: Computers, Chess and Long-Range Planning, by Michail M. Botvinnik

In the null-move context, to determine attack/defense targets and trajectories see also Botvinnik-Markoff Extension. Botvinnik already proposed Vector Attacks aka 15x15 boards with superimposed lookup as used in Pioneer.