Search found 1885 matches

by mar
Tue Apr 23, 2019 2:21 pm
Forum: Computer Chess Club: General Topics
Topic: Stockfish misevaluations:
Replies: 28
Views: 764

Re: Stockfish misevaluations:

Raphexon wrote:
Tue Apr 23, 2019 1:58 pm
Yea, 92/97, 600 billion visited nodes and it's still a +5.38.
could you post the PV please?
by mar
Mon Apr 22, 2019 3:46 pm
Forum: Computer Chess Club: General Topics
Topic: Stockfish misevaluations:
Replies: 28
Views: 764

Re: Stockfish misevaluations:

Henk wrote:
Mon Apr 22, 2019 3:24 pm
Maybe best is to evaluate a position by playing some games and taking the average score. I don't know. Looks like alpha beta fails.
Zero method would do better.
Maybe a random mover would score this position properly as 0.0
by mar
Mon Apr 22, 2019 3:43 pm
Forum: Computer Chess Club: General Topics
Topic: Stockfish misevaluations:
Replies: 28
Views: 764

Re: Stockfish misevaluations:

With the Bishop on b5 the only Pawn you can sac is the g-Pawn, and after fxg4 black will simply put his King on f5, and white has nothing. Actually I would not be surprised if it was lost for white after such a sac. Yes, maybe I was too optimistic and this is indeed a draw with perfect play. Is the...
by mar
Mon Apr 22, 2019 3:06 pm
Forum: Computer Chess Club: General Topics
Topic: Stockfish misevaluations:
Replies: 28
Views: 764

Re: Stockfish misevaluations:

And what's wrong with that? White will eventually sac a pawn, break free and win the game :shock:
It will take some time with 50 move rule, sure, but white will win.
by mar
Sun Apr 21, 2019 11:48 am
Forum: Computer Chess Club: General Topics
Topic: Contrived position for perft
Replies: 14
Views: 362

Re: Contrived position for perft

Does it cover all the possibilities? Has someone done a better one already? Any suggested changes? r3k2r/1bp2pP1/5n2/1P1Q4/1pPq4/5N2/1B1P2p1/R3K2R b KQkq c3 0 1 Thanks I don't remeber one position to test all cases, not sure if it's possible; if so then it would be really nice if you don't have to ...
by mar
Sat Apr 20, 2019 11:49 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: No standard specification for Perft
Replies: 22
Views: 443

Re: No standard specification for Perft

in my regular search I never promote to bishop because that is clearly a waste of time. Is this really worth it? I always consider all legal moves in search and never even considered doing anything like that. Besides there are other ways to avoid wasting time on bishop underpromotions rather than c...
by mar
Thu Apr 18, 2019 8:24 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: My newest almost bb move generator is wonderful
Replies: 16
Views: 936

Re: My newest almost bb move generator is wonderful

And the bsf and bsr instructions are clock tick inefficient. Does this still hold on modern CPUs? Anyway, since you're hunting for cycles, one more low hanging fruit for you: mark default case in your switches unreachable to eliminate bounds check, turning the switch into plain jump table, making y...
by mar
Tue Apr 16, 2019 9:57 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Google's bfloat for neural networks
Replies: 2
Views: 335

Re: Google's bfloat for neural networks

I misread as "Google's bloat...", thought that Google open sourced yet another masterpiece :D So this bfloat16 is basically float where you throw away 16 bits worth of mantissa. Packing/unpacking from 32-bit float should be trivial, so probably clever, but hey only 7 bits of mantissa, is it really e...
by mar
Fri Mar 29, 2019 1:19 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Some x64 assembler for the curious
Replies: 21
Views: 1798

Re: Some x64 assembler for the curious

And a good compiler will translate a (considerable) switch-case in a jump table anyway. True, but you still need the switch inside the loop. Also, the compiler typically generates code to verify that the expression you switch on is in a valid range. You can still hint the compiler that default is u...
by mar
Sat Mar 23, 2019 12:39 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Some x64 assembler for the curious
Replies: 21
Views: 1798

Re: Some x64 assembler for the curious

Yes, first n args are passed in registers, but I like having twice the number of registers more. I haven't done any serious assembly in years though (except for a stub that passes control to generated machine code for my scripting language) It's worth noting that addresses use 64-bit registers by de...