Search found 466 matches

by Robert Pope
Mon May 13, 2019 2:28 pm
Forum: Computer Chess Club: General Topics
Topic: Opposite Color Bishop Endgames
Replies: 43
Views: 3438

Re: Opposite Color Bishop Endgames

It's all in your mind, which apparently is running completely amok. Virtually nothing you say is remotely connected to reality, especially when you think you can read other people's mind. Apparently it outrages you that LC0 is pretty poor at tactics, as far as chess engines go. And obviously you th...
by Robert Pope
Thu May 09, 2019 9:05 pm
Forum: Computer Chess Club: General Topics
Topic: Bluefish vs Leela in TCEC , who will win? BF =170 Threads, Lc0 =2x GPU
Replies: 40
Views: 4682

Re: Bluefish vs Leela in TCEC , who will win? BF =170 Threads, Lc0 =2x GPU

They are claiming that the net is in essence a book as well as an evaluation function. Of course, in many ways, Stockfish is as well , they just spend little time tuning the part that would help discriminate between lines in the opening. But the size of the SF evaluation function is very small (the...
by Robert Pope
Thu May 09, 2019 5:54 pm
Forum: Computer Chess Club: General Topics
Topic: Bluefish vs Leela in TCEC , who will win? BF =170 Threads, Lc0 =2x GPU
Replies: 40
Views: 4682

Re: Bluefish vs Leela in TCEC , who will win? BF =170 Threads, Lc0 =2x GPU

People on this forum have said that LCzero has a 40 MB pre calculated cache of moves . I wish that the TCEC would run an experiment letting SF use the latest Brianfish or else disabling LCzeros cache of moves. LOL... Leela is open source, anyone can go and check for that. There's nothing like that....
by Robert Pope
Mon May 06, 2019 4:23 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: A bug is squashing me. HELP!
Replies: 20
Views: 2639

Re: A bug is squashing me. HELP!

I think you have your if (tree[i].score > alpha) { if (tree[i].score >= beta) { return beta; backwards. You need to check for a beta cutoff first. EDIT: Or on second thought maybe it doesn't really have to, but you are adding an extra "if" statement for beta cutoffs. If you are always returning the ...
by Robert Pope
Mon May 06, 2019 4:17 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Time reduction adding a/b to mini/max?
Replies: 9
Views: 1218

Re: Time reduction adding a/b to mini/max?

With a mean branching factor of 30, minimax should take about 30^6 = 729 million nodes to search to depth 6. alpha-beta search with random ordering should take around ((30 - 1 + sqrt(30^2+14*30+1)/4)^6) = 305 million nodes. The expected time taken for alpha-beta given your minimax time of 30 second...
by Robert Pope
Fri Apr 26, 2019 5:01 pm
Forum: Computer Chess Club: General Topics
Topic: Is it possible to have and EPD string wider than 79 chars
Replies: 4
Views: 474

Re: Is it possible to have and EPD string wider than 79 chars

That's only 79, though, isn't it? I think that is going to be the max, since the only way to get it longer is to add castling flags. And a castling flag would mean there is a 2 space gap, eliminating the extra character advantage.
by Robert Pope
Fri Apr 19, 2019 7:34 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: No standard specification for Perft
Replies: 22
Views: 3949

Re: No standard specification for Perft

Huh. Though if you read the actual article about RCSE-1, all it says is that it calculated the number of depth 3 leaf positions at 8902, which is equivalent to what perft(3) does, not that they invented or implemented the perft command. Somebody back in 1500 wrote down all 20 legal opening moves. Th...
by Robert Pope
Fri Apr 19, 2019 6:04 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: No standard specification for Perft
Replies: 22
Views: 3949

Re: No standard specification for Perft

If the move generator only generates pseudo valid moves, then leaf node have to be validated and thus probably make/validated/unmake or copy/make/validated. Am I wrong ? That is true. However, the wiki says to only generate legal moves. It doesn't say to only generate legal moves, it says to only c...
by Robert Pope
Fri Apr 19, 2019 6:00 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: No standard specification for Perft
Replies: 22
Views: 3949

Re: No standard specification for Perft

Robert Pope & abulmo2, no argument from me on that except it should be called Accut for accuracy test instead of Perft for performance test. Apparently, whomever first wrote Perft was concerned with raw performance with an accurate count as a side effect bonus that became the focus for some. So, it...
by Robert Pope
Fri Apr 19, 2019 4:27 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: No standard specification for Perft
Replies: 22
Views: 3949

Re: No standard specification for Perft

Perft is intended to measure/validate move generation and tree travel accuracy. Everything else is stuff that other people have decided to measure about it, but really aren't its focus. It really isn't a performance metric. And qsearch is entirely irrelevant to it.