Search found 324 matches

by noobpwnftw
Sun Mar 11, 2018 1:07 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: 7-men Syzygy attempt
Replies: 588
Views: 119252

Re: 7-men Syzygy attempt

The encoding/decoding scheme in principle can deal with that, but there may be a 32-bit overflow in an intermediate calculation. Thank you for this information, then I will look into it and see if I can fix the index calculation overflow first. They all have the same size/index range. Indeed, they ...
by noobpwnftw
Sun Mar 11, 2018 6:17 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: 7-men Syzygy attempt
Replies: 588
Views: 119252

Re: 7-men Syzygy attempt

Found the thread:
http://www.talkchess.com/forum/viewtopic.php?t=59947

And the crash above seems to be the tb_size calculation from permute type 0 is not the largest possible in trylist.
by noobpwnftw
Sat Mar 10, 2018 11:11 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: 7-men Syzygy attempt
Replies: 588
Views: 119252

Re: 7-men Syzygy attempt

Also I tried building KRBNvKQN which has the longest mate among pawnless 7-men TBs, the step counter should overflow: Iteration 241 ... done. ...omitted... Iteration 299 ... done. Iteration 300 ... find_val: not found! There is REDUCE_PLY which I believe halves the counter past it, but I strongly su...
by noobpwnftw
Sat Mar 10, 2018 4:14 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: 7-men Syzygy attempt
Replies: 588
Views: 119252

7-men Syzygy attempt

So with some fiddling and help from https://github.com/jjoshua2/tb/ It seems at least some of the 7-men TBs can be produced. Here is the current code: https://github.com/noobpwnftw/tb/tree/7-men, and here are all 3-6 men + some 7 men TBs I've generated so far: ftp://112.73.74.24/pub/syzygy/ However,...
by noobpwnftw
Sat Feb 24, 2018 3:55 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Some opening book design questions
Replies: 39
Views: 10372

Re: Some opening book design questions

Actually, Chess has every necessary parts ready(i.e. results from fishtest) to make a book by brute force. It might practically ultra-weak solve the opening.
by noobpwnftw
Fri Feb 23, 2018 2:23 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Some opening book design questions
Replies: 39
Views: 10372

Re: Some opening book design questions

It would then require 12(RCN) * 7 + 6(P) * 10 + 4(B) * 4 + 3(A) * 4 + 4(K) * 2 + 1(turn) = 181 bits or even less if palace states are combined. Although keys(either hash or other formats) are known before probing the book, unlike EGTBs that you won't store keys at all(accessed with data[index] = val...
by noobpwnftw
Fri Feb 23, 2018 6:56 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Some opening book design questions
Replies: 39
Views: 10372

Re: Some opening book design questions

1. Probing radix trees does not require comparisons of uncompressed form, so effectively I'm comparing for 7.34 bytes per position on average. 2. Fixed lengths or not do not really matter since you won't be storing your book as "data[index]" anyway. Sorted skip lists would seek just as fast. 3. http...
by noobpwnftw
Thu Feb 22, 2018 4:24 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Some opening book design questions
Replies: 39
Views: 10372

Re: Some opening book design questions

Crazy or not, here are some stats on binary encoded FENs from 8.85 billion stored positions in bytes: min-keylen = 17, max-keylen = 45, avg-keylen = 35.19, avg-zkey = 7.34 After compression(as shown by avg-zkey) it is actually less than 8 bytes, yet seeking among keys are close to O(1). You can appl...
by noobpwnftw
Wed Feb 21, 2018 7:42 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Some opening book design questions
Replies: 39
Views: 10372

Re: Some opening book design questions

Maybe that is because no one has ever built an opening database large enough for BW symmetry to matter. At least EGTBs implement them, so maybe we should do the same for openings, and doing so is not expensive. BTW, losing a tempo in the openings is never considered bad in Xiangqi, in fact, it is ve...
by noobpwnftw
Wed Feb 21, 2018 6:53 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Some opening book design questions
Replies: 39
Views: 10372

Re: Some opening book design questions

If you are meant for Xiangqi: 1. You can have a index scheme that stores only one of the mirrored positions (LR/BW/LRBW). Scores should remain the same with current moving player's perspective. Sample probing code here: https://github.com/noobpwnftw/chessdb/blob/master/db_bench_util/update.php 2. Us...