Search found 39 matches

by Jakob Progsch
Mon Aug 23, 2021 10:28 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Infinite Loop when using Extensions
Replies: 7
Views: 2852

Re: Infinite Loop when using Extensions

At one point I thought doing check extensions when there is only a single legal follow up would be safe to extend by two. Since any repetition would be caught by the repetition draw code. Turns out there are sequences of 50+ non-repeating moves with a queen chasing a king around the board. And those...
by Jakob Progsch
Wed Aug 11, 2021 10:23 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Lazy SMP and shared hash table
Replies: 22
Views: 5337

Re: Lazy SMP and shared hash table

That is an interesting use of buckets! Unfortunately I am not using buckets in my TT, so changing to this representation is a big change, as I am already introducing a whole new world of changes with Lazy SMP... but will see what happens, as I am still exploring ;) Well, I guess the buckets are jus...
by Jakob Progsch
Tue Aug 10, 2021 1:02 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Lazy SMP and shared hash table
Replies: 22
Views: 5337

Re: Lazy SMP and shared hash table

What I did recently is change my buckets to three elements stored in 4 uint64. The first uint64 is just a directory containing 21 bits of metadata per entry like age, depth, type and however many bits of signature fit after that. The remaining three entries then contain the rest of the signature as ...
by Jakob Progsch
Fri Aug 06, 2021 1:27 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: MinimalChess - how to move forward?
Replies: 26
Views: 9272

Re: MinimalChess - how to move forward?

Do you value the queen at 900 or 1000cp?

I use 1000cp and get -200 both as the final see value as well as for the full exchange.
by Jakob Progsch
Mon Aug 02, 2021 3:53 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: MG | EG experiment
Replies: 6
Views: 2521

Re: MG | EG experiment

I occasionally think there should be some way to "compress" those big arrays in case you want multiple PSTs. In the simplest case you create all the PSTs for all the king positions and then you do a principal component analysis on the resulting tables. You can then probably single out some "base PST...
by Jakob Progsch
Mon Jul 26, 2021 1:49 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Static exchange evaluation with promotion
Replies: 23
Views: 7519

Re: Static exchange evaluation with promotion

Essentially, the initial attacker would never hit on the promotion rank, when it can be re-hit by a pawn. The standing-pat is necessarily better in that. case. That may be the argument/"proof" I was looking for in my previous post. If the target square is threatened by a promoting pawn the threat o...
by Jakob Progsch
Mon Jul 26, 2021 11:08 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Static exchange evaluation with promotion
Replies: 23
Views: 7519

Re: Static exchange evaluation with promotion

Can this be fixed by adjusting the part in the wiki version that deals with pruning? Essentially you can stop the process once the line becomes non forcing by not flipping the sign between two moves. So that would be the point where you want to play your "trump card" which is the promotion capture?
by Jakob Progsch
Mon Jul 26, 2021 10:24 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Static exchange evaluation with promotion
Replies: 23
Views: 7519

Re: Static exchange evaluation with promotion

The pawn hitting there get assigned a value of Q - P, and their captures are not generated first but between rook and queen captures. I'm not convinced yet that this is correct. Don't you have to consider both orderings for those pawns? Consider this position for example and the move Bxd8: 2nN3r/2P...
by Jakob Progsch
Sun Jul 25, 2021 9:16 am
Forum: Computer Chess Club: General Topics
Topic: UEAL - Unique Engine Authors License?
Replies: 10
Views: 3749

Re: UEAL - Unique Engine Authors License?

I was thinking about something similar. Chess engines are an interesting kind of software in the sense that they are a form of "competitive programming" which makes standard open source licenses a less than perfect fit in some cases. There are strong arguments for the code being publicly available f...
by Jakob Progsch
Sun Jul 25, 2021 8:35 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Static exchange evaluation with promotion
Replies: 23
Views: 7519

Re: Static exchange evaluation with promotion

Thinking about this some more I'm now wondering about order in linear SEE. This is one of those examples where you stand to gain more from taking with the more valuable piece first. Iterative SEE implementation however rely on working their way up the values. Are there cases where bottom up linear a...