Search found 275 matches

by Sesse
Tue Mar 02, 2021 10:53 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Reaching high search depths
Replies: 10
Views: 609

Re: Reaching high search depths

- Null Move pruning ("If I do nothing in this position and I'm STILL better, I can cut the entire subtree off") AFAIK, this should still be exact; but after that, you get into the realm of "real" pruning: discarding moves you think will *probably* not be good... but this does indeed take some risks...
by Sesse
Fri Feb 19, 2021 7:52 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: C++ type system AKA what is exactly int ?
Replies: 17
Views: 963

Re: C++ type system AKA what is exactly int ?

It is unlikely we'll be seeing 128-bit CPUs. Traditionally, the shift to wider architectures have been due to the need to address more RAM, not do arithmetic on bigger values, and 2 EB of RAM seems to be enough for a while… (Typically address space in current 64-bit CPUs is not even full 64-bit.) It...
by Sesse
Wed Feb 17, 2021 11:04 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Penalizing early queen development
Replies: 4
Views: 271

Re: Penalizing early queen development

Most engines have two different sets of evaluation weights for most features: Middlegame (which includes the opening) and endgame. In the endgame, centralizing the queen is great; in the middlegame, you want it more hidden. How does the engine know which phase the game it's in, without counting the ...
by Sesse
Tue Feb 16, 2021 8:33 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: C++ type system AKA what is exactly int ?
Replies: 17
Views: 963

Re: C++ type system AKA what is exactly int ?

Bo Persson wrote:
Mon Feb 15, 2021 8:41 am
No, it is guaranteed to be the size of unsigned char, which is the smallest possible type in C++ (sizeof(byte) == 1).
Well, to be accurate, the smallest possible addressable type. You can have bitfields that are smaller.
by Sesse
Mon Feb 15, 2021 8:30 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: C++ type system AKA what is exactly int ?
Replies: 17
Views: 963

Re: C++ type system AKA what is exactly int ?

Depends on your target platform. int is at least 16 bits, but may be more. The only case where int doesn't fit in a CPU register is 8 bit controllers such as small AVRs. char is always 8 bits in practice - technically, it is the smallest addressable memory unit that can hold the basic character set...
by Sesse
Sun Feb 14, 2021 10:49 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: C++ type system AKA what is exactly int ?
Replies: 17
Views: 963

Re: C++ type system AKA what is exactly int ?

C++ is vague on this; int must be at least as large as short, and no larger than long. In addition, it must be signed, capable of holding [INT_MIN, INT_MAX], and “have the natural size suggested by the architecture of the execution environment”. On all modern PCs, int is 32 bits. If you code for MS-...
by Sesse
Tue Feb 09, 2021 11:56 pm
Forum: Computer Chess Club: General Topics
Topic: Fat Fritz 2
Replies: 491
Views: 29288

Re: Fat Fritz 2

I hate to say it, but I do agree with Dkappe. Whether the data is compiled in or not is mostly meaningless. This is true, and the license is clear on that (“however packaged”). What matters is that they are selling a combined work. UnoriginalFritz2 could just as easily obtain the same result by 1) ...
by Sesse
Tue Feb 09, 2021 11:54 pm
Forum: Computer Chess Club: General Topics
Topic: Fat Fritz 2
Replies: 491
Views: 29288

Re: Fat Fritz 2

That’s not how copyright works. The whole work doesn’t magically become GPL just because you are in violation of the license. For example, if someone distributes one of my nets embedded in a GPLv3 licensed engine, that doesn’t mean I give up my copyright. Actually that is how copyright works, only ...
by Sesse
Tue Feb 09, 2021 11:36 pm
Forum: Computer Chess Club: General Topics
Topic: Fat Fritz 2
Replies: 491
Views: 29288

Re: Fat Fritz 2

The net and engine might be covered by different licenses, as is the case with Stockfish (GPLv3) and the stockfish networks (creative commons). If they are, and the licenses are not compatible (which very roughly means that one is a subset of the other), you simply cannot combine them into one work...
by Sesse
Mon Feb 01, 2021 10:40 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: seldepth: what is the correct way to calculate this?
Replies: 15
Views: 1658

Re: seldepth: what is the correct way to calculate this?

I've seen Stockfish report lower seldepth than depth! (I guess all moves were reduced pretty hard at some point.) AFAIK it uses the same notion of “seldepth is the highest depth we've ever reached”.