Search found 640 matches

by Desperado
Sun Jul 12, 2020 11:59 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Questions on Razoring and Code Structure for Pruning
Replies: 19
Views: 414

Re: Questions on Razoring and Code Structure for Pruning

The problem is, how do you know you know you attack two pieces?... You do not need to know that! The reason why a move is strong and why you decide to search the subtree might be different. If you exclude a killer move because you expect a killer to be strong for any reason it might be because of a...
by Desperado
Sat Jul 11, 2020 12:28 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Questions on Razoring and Code Structure for Pruning
Replies: 19
Views: 414

Re: Questions on Razoring and Code Structure for Pruning

Well, it is very simple. It is not about different margins, it is about that quiet moves can change the static score drastically. e.g: if a pawn push from d2 to d4 attacks a Knight on c5 and that frees a bishop on c1 to attack the opponent queen on g5 ... that's it. To ignore them in the test "outs...
by Desperado
Sat Jul 11, 2020 11:55 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Questions on Razoring and Code Structure for Pruning
Replies: 19
Views: 414

Re: Questions on Razoring and Code Structure for Pruning

Outside of the loop, the current state of the art is to consider a position for a test, which evaluation is so bad, that it will most likely not get above alpha, the lower bound. For this purpose, a quiescence search is performed, since the idea is that "only" capture moves can achieve a big differ...
by Desperado
Sat Jul 11, 2020 10:59 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Questions on Razoring and Code Structure for Pruning
Replies: 19
Views: 414

Re: Questions on Razoring and Code Structure for Pruning

Hi, I have recently added in extended futility pruning (up to 3 plys) and am having some positive success. I am reading about Razoring, have tried laying in some flavors of code, tests are not positive. I also decided to look at some other code and now wonder about more than razoring but also code ...
by Desperado
Fri Jul 10, 2020 7:08 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Question on Texel's Tuning Method
Replies: 14
Views: 510

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...
by Desperado
Fri Jul 10, 2020 3:03 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Question on Texel's Tuning Method
Replies: 14
Views: 510

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...
by Desperado
Mon Dec 10, 2018 8:21 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Gradient Descent Introduction
Replies: 4
Views: 1435

Re: Gradient Descent Introduction

Thanks both of you so far. Unfortunately my time is very limited, so there might be a delay for further posts. Now,first, i would like to follow Matthew's description and i would appreciate if you can guide me through. Let's start very simple, and say each training example has an input x (let's say ...
by Desperado
Sun Dec 09, 2018 2:32 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Gradient Descent Introduction
Replies: 4
Views: 1435

Gradient Descent Introduction

Hello everybody, i am interested in a simple gradient descent implementation. Unfortunately i am not able to put the puzzle pieces together. Here is what i think that i understand and what i can do for now: base model: 1. i have a sample set of positions including results 2. i have a parameter list ...
by Desperado
Mon Oct 29, 2018 7:57 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: very small bitboard move/attack generator
Replies: 10
Views: 3170

Re: very small bitboard move/attack generator

// simple direct computations for sliders (unify bishop and rook for queen attacks) uint64_t Eng::gen_b_attack(int s, uint64_t o) { uint64_t tmp, att = 0; remove_bit(&o,s); tmp = Setbit64(s); while(False(tmp & (o | BB_HF | BB_R8))) att |= tmp <<= 9; tmp = Setbit64(s); while(False(tmp & (o | BB_AF | ...
by Desperado
Wed Jun 07, 2017 4:00 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Texel tuning method question
Replies: 63
Views: 18579

Re: Texel tuning method question

If i come close with my understanding which would mean a static score from the pv leaf, i bet it provides the same noise as any other static score you compute in any other situation. What you seem to miss is that the tuning method doesn't use only the score, but also the gradient of the score, i.e....