Search found 842 matches

by Joost Buijs
Sun Jun 09, 2019 7:41 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: is LVA as in MVV-LVA useless ?
Replies: 9
Views: 565

Re: is LVA as in MVV-LVA useless ?

SEE is perfectly useable for ordering captures, the problem is that you have to calculate SEE for all captures before you can sort them and this is somewhat slower than calculating MVV-LVA for all captures. In my main search I use SEE throughout for ordering captures, in quiescence I use MVV-LVA for...
by Joost Buijs
Sat Jun 08, 2019 2:07 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Hash collision?
Replies: 42
Views: 1418

Re: Hash collision?

In Stockfish, the ratio of false hits is one in every 2^16/3 = 21845 probes, so one in every 16384 is unlikely to do a lot of damage. Maybe Stockfish doesn't probe on every node (position) it generates, I don't know. But if it does, and you run on a fairly modern PC it can have like 1000 false hits...
by Joost Buijs
Sat Jun 08, 2019 5:31 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Is this hard ?
Replies: 12
Views: 427

Re: Is this hard ?

Does not seem very hard, without TB my engine thinks within a millisecond h4-h5 is the best move, however it does not find a win. h4-h5 is solely played on positional grounds, at least that is my guess. info depth 1 score cp 324 time 0 nodes 86 nps 86 tbhits 0 pv h4h5 f1g1 g4f4 info depth 2 score cp...
by Joost Buijs
Fri Jun 07, 2019 1:48 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: correct way to score promotions using MVV-LVA
Replies: 6
Views: 321

Re: correct way to score promotions using MVV-LVA

Ras wrote:
Fri Jun 07, 2019 12:51 pm
Dann Corbit wrote:
Thu Jun 06, 2019 10:37 pm
Including underpromotion to knight?
Yes, it's not worth the effort in QS. In main search however, underpromotions should be searched.
Even in main search you can omit under-promotions to bishop, at least I've never seen a game where under-promotion to bishop led to anything useful.
by Joost Buijs
Thu Jun 06, 2019 6:17 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Hash collision?
Replies: 42
Views: 1418

Re: Hash collision?

Really? I'm not an expert by any means, but a 16 bit key will give you many collisions each second, so it is very likely that this is the problem. The idea is that you store say n bits as hash in the table and use another m bits to compute the TT index. Unless I miscalculated, a 4MB hash table with...
by Joost Buijs
Wed Jun 05, 2019 6:31 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Hash collision?
Replies: 42
Views: 1418

Re: Hash collision?

Really? I'm not an expert by any means, but a 16 bit key will give you many collisions each second, so it is very likely that this is the problem. Maybe 16 bits is somewhat faster (what I doubt), and it will save some memory, but it is better to be safe than sorry. I use a 64 bit key and a 64 bit da...
by Joost Buijs
Tue Jun 04, 2019 5:26 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: is LVA as in MVV-LVA useless ?
Replies: 9
Views: 565

Re: is LVA as in MVV-LVA useless ?

I don't see any reason why Stockfish prefers MVV over MVV-LVA, they talk about code complexity but to me it seems that one additional subtraction is not very complex at all, probably it tested 0.1 Elo better.
by Joost Buijs
Wed May 29, 2019 2:05 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: bizarre behavior by Leela
Replies: 10
Views: 1103

Re: bizarre behavior by Leela

Isn't this bug already solved a long time ago? You're probably right, it only seems to happen when I compile against older Win SDK (8.1 or earlier). It also happens when I try to compile for WinXP, no idea if it's related. No idea either, I haven't compiled for WinXP in ages, the last time I used W...
by Joost Buijs
Mon May 27, 2019 4:54 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: bizarre behavior by Leela
Replies: 10
Views: 1103

Re: bizarre behavior by Leela

mar wrote:
Mon May 27, 2019 3:44 pm
mar wrote:
Mon May 27, 2019 2:09 pm
I don't do this in Cheng, so it's not fully idiot-proof.
Correction: Cheng does report an error (not the offending move though) - I fell for the msc stdlib bug again, where you have to manually enter twice. Sigh...
Isn't this bug already solved a long time ago?
by Joost Buijs
Mon May 27, 2019 11:07 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: bizarre behavior by Leela
Replies: 10
Views: 1103

Re: bizarre behavior by Leela

Note the illegal e7d8 instead of the correct d7h3 Not to sure what Leela is smoking but it doesn't look good. position startpos moves e2e4 c7c5 g1f3 d7d6 d2d4 c5d4 f3d4 g8f6 f1d3 b8c6 d4c6 b7c6 e1g1 g7g6 c1g5 f8g7 b1c3 h7h6 g5e3 f6g4 d1d2 g4e3 d2e3 d8b6 e3b6 a7b6 a2a3 e7e6 a1b1 e8e7 c3e2 c8d7 c2c3 ...