Search found 3002 matches

by lucasart
Sat Feb 01, 2020 1:08 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Stockfish Reverts 5 Recent Patches
Replies: 9
Views: 2779

Re: Stockfish Reverts 5 Recent Patches

I wonder if this could lead to some paradigm shift. For over a decade it was assumed that small, incremental changes which are functionally independent are generally additive. Revert 5 patches which were merged, but lead to a regression test that showed negative Elo gain: http://tests.stockfishches...
by lucasart
Wed Jan 29, 2020 11:50 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: hash collisions
Replies: 370
Views: 34094

Re: hash collisions

The problem is not necessarily linked to the hash move. In fact, in Demolito, what caused crashed was not related to that at all. Demolito does not play the hash move, it simply generates moves, and sort them, giving highest score if a move happens to equal the hash move. So testing legality of has...
by lucasart
Wed Jan 29, 2020 12:04 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: hash collisions
Replies: 370
Views: 34094

Re: hash collisions

If his engine crashes, then he should fix his hashmove validation. :roll: A better test is to generate all possible moves during search (in hashmove format of course, typically 16 bits), generate all legal moves per node and make sure your validator correctly classifies these as legal/illegal. Afte...
by lucasart
Mon Jan 27, 2020 12:03 am
Forum: Computer Chess Club: Tournaments and Matches
Topic: 78th Amateur Series Division 2
Replies: 11
Views: 1588

Re: 78th Amateur Series Division 2

78TH AMATEUR SERIES (Division 2) Intel i5 Quad ChessGUI 256mb hash each where possible 3-4-5 piece tablebases Ponder off Perfect2019.cgb book 40 moves in 25 minutes repeating (adapted for the CCRL) 4 cycles 44 rounds All engines 1CPU (64-bit where available) The top engine will gain automatic promo...
by lucasart
Wed Jan 08, 2020 4:20 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: RMO - Randomized Move Order - yet another Lazy SMP derivate
Replies: 114
Views: 16217

Re: RMO - Randomized Move Order - yet another Lazy SMP derivate

It is only the fixed depth tests that I prefer v4, but there is no reason not to stop the search if one thread reaches the depth limit. It turns out Stockfish can be made stronger by simply repeating a single-threaded search at a given depth a number of times. In fact, it seems a single-threaded se...
by lucasart
Tue Jan 07, 2020 4:39 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: RMO - Randomized Move Order - yet another Lazy SMP derivate
Replies: 114
Views: 16217

Re: RMO - Randomized Move Order - yet another Lazy SMP derivate

Vondele did an interesting experiment : I implemented 5 versions (drafts: https://github.com/vondele/Stockfish/commits/threadDepth) v1: Master version: all threads search irrespective of Limits.depth, mainThread stops search when it reaches limits depth. v2: First thread to reach Limits.depth stops...
by lucasart
Sun Jan 05, 2020 11:38 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: RMO - Randomized Move Order - yet another Lazy SMP derivate
Replies: 114
Views: 16217

Re: RMO - Randomized Move Order - yet another Lazy SMP derivate

sorry, what do you mean by SHT? Shared transpositio table? SHT and Lazy are the same thing. SHT is the real name, dating back from times immemorial: https://www.chessprogramming.org/Shared_Hash_Table Lazy is just a silly name coined in this forum a few years ago, and was refering to a completely mi...
by lucasart
Sun Jan 05, 2020 10:39 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: RMO - Randomized Move Order - yet another Lazy SMP derivate
Replies: 114
Views: 16217

Re: RMO - Randomized Move Order - yet another Lazy SMP derivate

SF uses skip depth scheme, so the reported depth is misleading and massively understated. This is wrong. Depth skipping has been removed from Stockfish over 9 months ago, because it scales awfully at longer TCs. See https://github.com/official-stockfish/Stockfish/pull/1972 Current Stockfish doesn't...
by lucasart
Sun Jan 05, 2020 6:02 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: RMO - Randomized Move Order - yet another Lazy SMP derivate
Replies: 114
Views: 16217

Re: RMO - Randomized Move Order - yet another Lazy SMP derivate

It looks "ridiclous theory number 1" could be the winner :) I redid the test at fixed depth=8 but this time constraining all 8 threads to 1 cores using "taskset -c 0 ./cutechess-cli", and i can see only 100% cpu usage when the previous test was 800% cpu usage. So both the single thread and multi-th...
by lucasart
Sat Jan 04, 2020 5:52 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: RMO - Randomized Move Order - yet another Lazy SMP derivate
Replies: 114
Views: 16217

Re: RMO - Randomized Move Order - yet another Lazy SMP derivate

Dann Corbit wrote:
Sat Jan 04, 2020 4:04 am
Why not a hybrid?

Half of the threads are using Lazy SMP to update the hash table.
The other half of the threads are using DTS/YBW/ABDADA to update the hash table.
Or some other mix as a function of thread count, hash table size, and time.
Talk is cheap. Show us your code :lol: