Search found 73 matches

by jstanback
Thu Jan 30, 2020 3:51 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: hash collisions
Replies: 370
Views: 34796

Re: hash collisions

Hi Bob, As I mentioned in my previous post, I don't think storing a 64 bit hash signature is enough even now on hardware like at TCEC. Wasp used "only" 16G of hash memory = 1G positions, so 30 bits is used up in the address. Since the table is always full of entries, that leaves 34 bits of useful ve...
by jstanback
Tue Jan 28, 2020 4:42 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: hash collisions
Replies: 370
Views: 34796

Re: hash collisions

Wasp had 3 crashes in the recent TCEC tournament where it used 128 threads and a 16 Gbyte hash table. I was unable to duplicate the crashes using 32 threads and an 8 Gbyte hash table even after many tries searching the position prior to the crash to fill the hash table and then the position Wasp cra...
by jstanback
Sun Dec 29, 2019 4:07 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: ELO value of TTSE?
Replies: 5
Views: 1260

Re: ELO value of TTSE?

I've never been able to get any gain from singular extension so I don't use it in Wasp. I must not be implementing it correctly or it doesn't play nicely with my extensions and reductions.

John
by jstanback
Mon Dec 16, 2019 4:34 pm
Forum: Computer Chess Club: General Topics
Topic: Null move test
Replies: 3
Views: 682

Re: Null move test

Hi Jon, Good position! Coincidentally, I was experimenting will null-move reduction yesterday on a similar endgame with only one minor per side. Here is the position 8/p2b2p1/3P1p2/4k3/1B5P/3K4/8/8 b - - In Wasp I allow NMP if the side to move has one or more pieces. If the null-move search fails hi...
by jstanback
Sat Nov 30, 2019 4:35 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Probing the transposition table at depth 0
Replies: 5
Views: 1198

Re: Probing the transposition table at depth 0

In Wasp I get some benefit by storing positions in Qsearch at depth=0, but only if a move increased alpha. I probe the hash table for depth >= 0.

John
by jstanback
Sun Sep 15, 2019 2:50 pm
Forum: Computer Chess Club: General Topics
Topic: Wasp 3.75 by John Stanback released ...
Replies: 16
Views: 3746

Re: Wasp 3.75 by John Stanback released ...

Thanks Ferdy. I'm working on fixing this for the next release.

John
by jstanback
Sat Sep 14, 2019 10:17 pm
Forum: Computer Chess Club: General Topics
Topic: Wasp 3.75 by John Stanback released ...
Replies: 16
Views: 3746

Re: Wasp 3.75 by John Stanback released ...

I made a change where if the first move at the root fails low several times (score has dropped about 2 pawns or more) then I accept that score for the first move, set a flag, and search the remaining moves to see if one of them is better. If not, then I repeat the iteration. Looks more like a hack ...
by jstanback
Sat Sep 14, 2019 10:09 pm
Forum: Computer Chess Club: General Topics
Topic: Wasp 3.75 by John Stanback released ...
Replies: 16
Views: 3746

Re: Wasp 3.75 by John Stanback released ...

Tried testing it with UCI_Elo 1500 at TC 60s+100ms and it losses on time forfeit. Sample games: Hi Ferdy, Thanks for bringing this to my attention. Wasp handles the UCI_Elo command by reducing the nodes/second. At 1500 Elo the target search rate is only about 24 nodes/second. In my time handling ro...
by jstanback
Fri Sep 06, 2019 10:25 pm
Forum: Computer Chess Club: General Topics
Topic: Wasp 3.75 by John Stanback released ...
Replies: 16
Views: 3746

Re: Wasp 3.75 by John Stanback released ...

Hi Frank! Thanks for pointing out these games to me. I don't spend nearly enough time reviewing games. In the Hakkapeliitta-Wasp game, after white played 20. Qh6, Wasp thinks Qc7 is a draw until it fails low at depth 23 (in about 6 sec). Wasp continues to reduce alpha and re-search many times until ...
by jstanback
Sat Jul 20, 2019 5:00 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Feature score use in search
Replies: 5
Views: 1279

Re: Feature score use in search

I forgot to mention that my eval hash table is separate from my main hash table and it includes the danger[] term in addition to the overall evaluation.

John