alip#jja is packaged for #Gentoo, quick #emerge #jja and do toot post "$(jja quote) #chess #chesspunks #quotes" and join the fun! https://packages.gentoo.org/packages/games-board/jja
No #Zobrist hash collisions were found in unique #chess positions from lichess games (2013-2014). The study will expand to 2023. Despite optimizing #SQLite for the expanding data, import times remain high, prompting a potential switch to #PostgreSQL for parallel import. Final results will be in #SQLite format. #jja
Improving cache efficiency has made #Stockfish hash almost double as fast for #jja: https://git.sr.ht/~alip/jja/commit/604366959060cffa8a02f14a039353f15732fa09 #rust #rustlang #chess
The #Zobrist hash function used in Polyglot opening books is roughly 2.4 times faster than the #Zobrist hash #Stockfish uses for their transposition table. One reason is because the former uses a constant array of random u64 numbers to generate randomness whereas the latter uses a #PRNG with a constant seed. Also former requires pseudo-legality for en-passant whereas latter requires full-legality. #jja #chess
#rust tip of the day: avoiding useless clones can make significant increases in code efficiency: https://git.sr.ht/~alip/jja/commit/04edb12 #jja
% for p in lichess_db_standard_rated_20*.pgn.zst; do echo "-- ${p} --"; jja dump "$p" | jja restore /caissa/pgn/alip.jja || break; done #yolo #jja #chess #sqlite #lichess restore returns non-zero when a hash collision is detected so break means collision. This way we hope to detect at least one #Zobrist hash collision. We have roughly 4,5T free space atm.
For purely academic reasons, I have added some tooling around #jja, to compile a huge #Zobrist hash to #chess position database which is structured such that we're able to detect hash collisions. I have indexed 100mio unique positions so far. No collisions found. How many #Zobrist hashes is it going to take to spot a collision I wonder?
To remove entries with zero depth from a #BrainLearn experience file you may do: "jja dump experience.exp | perl -F, -lane 'print if $F[1] > 0' | jja restore experience-nonull.exp" #jja #chess
New book online! caissa-ai, my #lichess bot, has not lost a single game against a 2900 bot whom they have never won against before. This book ist stronk \o/! Watch here https://lichess.org/@/caissa-ai/tv. Thank you @lichess! #jja #chess
