Search found 79 matches
- Thu Aug 06, 2020 3:06 pm
- Forum: Computer Chess Club: Programming and Technical Discussions
- Topic: negamax alpha beta search doesn't always return mating score
- Replies: 25
- Views: 4051
Re: negamax alpha beta search doesn't always return mating score
// associate best score with best move if (alpha != old_alpha) best_move = best_so_far; Is best_move a global? If yes, then shouldn't we only be setting this at the root of the search? Otherwise this might get set on moves at nearly the leaf of the tree, and should often be suggesting illegal moves.
- Fri Jul 31, 2020 4:34 pm
- Forum: Computer Chess Club: Programming and Technical Discussions
- Topic: Simplifying code
- Replies: 137
- Views: 59725
Re: Simplifying code
- Tried to write it functional. So recursion instead of loops. Recursion instead of iteration is pretty bad in languages without tail-call recursion. And, honestly, tail-call recursion is a hack to allow functional languages to have better performance than they should. - yes for debugging nested ex...
- Thu Jul 30, 2020 7:07 pm
- Forum: Computer Chess Club: Programming and Technical Discussions
- Topic: Simplifying code
- Replies: 137
- Views: 59725
Re: Simplifying code
Instead of calling .Aggregate(), you can call .Sum() to simplify. Even though the performance for perft isn't the biggest concern, there are 2 issues with using LinQ IMO: It creates additional objects, which need to be GCd. You lose some control over the sequence in which the code is executed. It ca...
- Mon Jul 27, 2020 6:51 am
- Forum: Computer Chess Club: Programming and Technical Discussions
- Topic: Implementing Contempt For The Draw
- Replies: 1
- Views: 1086
Re: Implementing Contempt For The Draw
It doesn't look like FirstChess will evaluate a draw for repetition or 50 move rule, so it will actually blindly stumble into those without realizing they terminate the game. The only draw FirstChess can see is stalemate, which I see on line 623. For contempt, there are 2 things to take into account...
- Thu Jul 23, 2020 6:03 pm
- Forum: Computer Chess Club: Programming and Technical Discussions
- Topic: Looking for automatic Engine Testing Software
- Replies: 51
- Views: 10628
Re: Looking for automatic Engine Testing Software
Which is your setting about resign and draw? How much CPU can be saved with it? I think it can be somewhat dangerous to use automatic adjudication in engine testing tournaments. This is for 2 reasons: there are some positions that engines typically see as a win but are actually drawn, and otherwise...
- Tue Jul 21, 2020 9:51 pm
- Forum: Computer Chess Club: Programming and Technical Discussions
- Topic: When a Node Type Changes...
- Replies: 2
- Views: 1479
Re: When a Node Type Changes...
So if I understand the matter correctly, here's a conclusion: If every PV node and cut node has perfect ordering (i.e. the PV move or a cut move is evaluated first), then you will see that every expected cut node will be a cut node, and every expected all node will be an all node. However, if a cut ...
- Fri Jul 10, 2020 3:45 pm
- Forum: Computer Chess Club: Programming and Technical Discussions
- Topic: Question on Texel's Tuning Method
- Replies: 14
- Views: 3592
Re: Question on Texel's Tuning Method
You should first convert your scores to win probabilities first so the big scores won’t dominate. It is the mean squares of the win probabilities you want to minimise. Yeah, texel tuning does this via a sigmoid function. It isn't only to get the probabilities but the absolute values will have a dif...
- Fri Jul 10, 2020 2:03 pm
- Forum: Computer Chess Club: Programming and Technical Discussions
- Topic: Question on Texel's Tuning Method
- Replies: 14
- Views: 3592
- Fri Jul 10, 2020 1:32 pm
- Forum: Computer Chess Club: Programming and Technical Discussions
- Topic: Question on Texel's Tuning Method
- Replies: 14
- Views: 3592
Re: Question on Texel's Tuning Method
The explanation of average scores of many similar positions does partially answer my question, but there's another aspect that I don't think I expressed well. When tuning something (an eval in chess, or anything else), your error function will determine what things are most important to your tuning ...
- Wed Jul 08, 2020 4:32 pm
- Forum: Computer Chess Club: Programming and Technical Discussions
- Topic: Question on Texel's Tuning Method
- Replies: 14
- Views: 3592
Question on Texel's Tuning Method
I have a theoretical question on Texel's tuning method. If I understand it correctly, the function takes a set of positions, and minimizes the mean squared error of the positions. The error in a position is the difference between the (adjusted) evaluation and the result of the game. Clearly this is ...