Search found 752 matches

by PK
Mon Apr 22, 2019 5:20 pm
Forum: Computer Chess Club: General Topics
Topic: Stockfish misevaluations:
Replies: 31
Views: 1015

Re: Stockfish misevaluations:

Perhaps it is a draw, perhaps a win, but it is white to move. Does any engine try immediate b5?
by PK
Mon Mar 11, 2019 7:42 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Creating a spoon of TSCP181
Replies: 13
Views: 899

Re: Creating a spoon of TSCP181

To avoid problems with spooning a non-free engine, I might be tempted to create a very basic bitboard engine. Interested?
by PK
Fri Mar 01, 2019 11:27 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Poor man's neurones
Replies: 9
Views: 1517

Re: Poor man's neurones

What I do is precisely about planning. My private engine has two competing scores for piece/square tables (one symmetric, one slanted towards kingside), and two mobility scores (one linear, one non-linear). The algorithm I described calculates the difference between two scores and tries to decide wh...
by PK
Thu Feb 28, 2019 5:46 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Poor man's neurones
Replies: 9
Views: 1517

Re: Poor man's neurones

I have found a working algorithm. I'm not claiming that it is any better than real neural network, and it is inefficient form traditional point of view, as the engine maintains twice as many piece/square tables. However, it does not cause too big a slowdown within a traditional evaluation function, ...
by PK
Tue Feb 12, 2019 7:46 am
Forum: Computer Chess Club: General Topics
Topic: Bad eval with 7 men syzygy
Replies: 9
Views: 809

Re: Bad eval with 7 men syzygy

I vaguely recall Tord Romastad's post on fishcooking list where he explained that overvaluing drawn positions is actually good for modern selective search. Getting "good drawn position" might indicate that there is some conversion to superior ending along the way, but it has been pruned one way or t...
by PK
Thu Jan 17, 2019 11:06 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Playing transposition table moves in the Quiescence search
Replies: 14
Views: 1620

Re: Playing transposition table moves in the Quiescence search

Tested that, probably with some depth limit, but failed narrowly (which does not mean anything for Your engine, the rating gap implies I must have failed on several techniques that work for You). IIRC Andscacs might be using it. The real fun comes when you print all the positions when quiescence sea...
by PK
Thu Jan 17, 2019 6:05 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Reinforcement Learning (RL) in real time paradigm
Replies: 12
Views: 1383

Re: Reinforcement Learning (RL) in real time paradigm

Michael, I will be glad if you prove me wrong. But even then I would search for ways to reduce game length. You want to feed transposition table with additional information, trusting that it will help to shape the final search. The idea looks good, as long as this information has a chance to be acce...
by PK
Tue Jan 15, 2019 10:39 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Reinforcement Learning (RL) in real time paradigm
Replies: 12
Views: 1383

Re: Reinforcement Learning (RL) in real time paradigm

I'm afraid this algorithm would search too many moves irrelevent for the second search to be competitive. But when I'm analysing positions under Arena, I often do the following: short search, taking back, longer search. Some tactics are found faster that way. I'd suggest the following: try that appr...
by PK
Thu Jan 10, 2019 1:36 pm
Forum: Computer Chess Club: General Topics
Topic: Testing a private chess engine
Replies: 0
Views: 530

Testing a private chess engine

A nameless entity, still weaker than Rodent (I'll release only if it becomes clearly stronger), got this amusing draw after a ridiculous pawn sack in the early middlegame: [Event "Impersontor2019-01(2)"] [Site "LAPTOP"] [Date "2019.01.09"] [Round "18"] [White "Rodentiii"] [Black "Impersonator"] [Res...
by PK
Fri Jan 04, 2019 5:50 pm
Forum: Computer Chess Club: General Topics
Topic: SchaakMachine: Clear win
Replies: 11
Views: 1345

Re: SchaakMachine: Clear win

I add noise in eval, pseudocode follows:

Code: Select all

((position->hashKey ^ randomValueObtainedAtGameStart) % noiseValue) - noiseValue / 2
This way random component of evaluation is always the same for the position, centered around zero, different in each game and does not pollute search code.