Search found 140 matches

by Fulvio
Tue Apr 23, 2019 11:42 am
Forum: Computer Chess Club: General Topics
Topic: Stockfish misevaluations:
Replies: 31
Views: 2484

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. +1 I played 3 games as black against Stockfish and lost them all. If you allow the b5 sac the queen enters using the dark squares and...
by Fulvio
Fri Apr 05, 2019 8:42 pm
Forum: Computer Chess Club: General Topics
Topic: Elements of the ULTIMATE Chess GUI?
Replies: 197
Views: 22024

Re: Elements of the ULTIMATE Chess GUI?

If we use MonetDB, then the data will be accessed at (approximately) memory speed. Do you have some concrete benchmark? Let's say a 10 million games database: how long it takes to find the games (not just the positions, if I would like to study the ending I need to see the continuation) with for ex...
by Fulvio
Fri Apr 05, 2019 8:16 pm
Forum: Computer Chess Club: General Topics
Topic: Elements of the ULTIMATE Chess GUI?
Replies: 197
Views: 22024

Re: Elements of the ULTIMATE Chess GUI?

sovaz1997 wrote:
Fri Apr 05, 2019 8:05 pm
For the ending, there are other solutions - the Nalimov tables, the Syzygy tables. I don't think that the database is suitable for this.
Oh... no positional search?
That's a very big limitation for the ULTIMATE Chess GUI...
by Fulvio
Fri Apr 05, 2019 8:01 pm
Forum: Computer Chess Club: General Topics
Topic: Elements of the ULTIMATE Chess GUI?
Replies: 197
Views: 22024

Re: Elements of the ULTIMATE Chess GUI?

If we use MonetDB, then the data will be accessed at (approximately) memory speed. Do you have some concrete benchmark? Let's say a 10 million games database: how long it takes to find the games (not just the positions, if I would like to study the ending I need to see the continuation) with for ex...
by Fulvio
Fri Apr 05, 2019 1:00 pm
Forum: Computer Chess Club: General Topics
Topic: Lc0 51010
Replies: 115
Views: 11684

Re: Lc0 51010

I don't think Mephisto III would beat a modern program restricted to the same nps. You picked the wrong word. You believe that a modern program plays decently even with restricted NPS. If you thought about it.... Let's see how Stockfish behave in the previous position, 200 seconds per 5NPS = 1000 n...
by Fulvio
Thu Apr 04, 2019 7:47 am
Forum: Computer Chess Club: General Topics
Topic: Lc0 51010
Replies: 115
Views: 11684

Re: Lc0 51010

I do not agree and I consider memorizing patterns of search as doing a search. Communication requires a shared terminology: https://www.chessprogramming.org/Evaluation https://www.chessprogramming.org/Search#Search_Algorithms How can you know that Nf7+ is bad without having in mind Nf7+ Qxf7 Qxf7 R...
by Fulvio
Wed Apr 03, 2019 6:00 pm
Forum: Computer Chess Club: General Topics
Topic: Lc0 51010
Replies: 115
Views: 11684

Re: Lc0 51010

knowing patterns help but you need search to verify. 4r2k/q5pp/8/3Q2N1/8/8/5PPP/6K1 w - - 3 1 Otherwise you play here Nf7+ and lose after Qxf7 You picked a bad example. I just checked lc0-network41752 and it sees both patterns: the smothered mate and the back-rank mate. The patterns are weighted: N...
by Fulvio
Fri Mar 29, 2019 3:35 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: On the establishment of domains wherein magic numbers can and cannot exist
Replies: 1
Views: 442

Re: On the establishment of domains wherein magic numbers can and cannot exist

A bishop on G8 is the easiest case, because all the relevant squares are aligned and well spaced. We can than decompose magic * bitboard into (magic * 2^square1) + (magic * 2^square2) + ... without worrying about collision and interference. With very few lines of code we can quickly find 48 valid** ...
by Fulvio
Wed Mar 27, 2019 5:21 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: No bishop magics with fixed shift 8
Replies: 17
Views: 2712

Re: No bishop magics with fixed shift 8

Some futher considerations, I hope the math is correct. For a bishop in C1, let's define: bitboard_D2 = 1 << 11; bitboard_E3 = 1 << 20; bitboard_D2_E3 = bitboard_D2 + bitboard_E3; If we search for a 4 bits hash, we know that: idx_bitboard_D2 > 0 && idx_bitboard_D2 < 16 idx_bitboard_E3 > 0 && idx_bit...
by Fulvio
Tue Mar 26, 2019 8:54 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: No bishop magics with fixed shift 8
Replies: 17
Views: 2712

Re: No bishop magics with fixed shift 8

we have selected the smallest possible numbers for hash values which avoid collisions with previously chosen hash values. That's the problem. We know that collisions can be valid. Picking powers of 2 generates big gaps, so it is necessary to demonstrate that all those gaps are filled with invalid c...