Search found 4578 matches

by syzygy
Sat Jun 26, 2021 11:53 pm
Forum: Computer Chess Club: General Topics
Topic: Stockfish no longer has contempt
Replies: 19
Views: 6502

Re: Stockfish no longer has contempt

Never understood why they had contempt in the first place, as it interfered with the accuracy of stockfish's evaluation by artificially inflating it by 24 centipawns, especially when it comes in a gui that does not allow the user to change uci options, such as the Lichess Stockfish interface. Stock...
by syzygy
Sat Jun 26, 2021 6:05 pm
Forum: Computer Chess Club: General Topics
Topic: Stockfish no longer has contempt
Replies: 19
Views: 6502

Re: Stockfish no longer has contempt

Never understood why they had contempt in the first place, as it interfered with the accuracy of stockfish's evaluation by artificially inflating it by 24 centipawns, especially when it comes in a gui that does not allow the user to change uci options, such as the Lichess Stockfish interface. Stock...
by syzygy
Tue Jun 15, 2021 1:49 pm
Forum: Computer Chess Club: General Topics
Topic: Fluctuations in Stockfish evaluation
Replies: 16
Views: 3717

Re: Fluctuations in Stockfish evaluation

Of course I have used 1 thread to avoid non-determination due multiple threads. If the single-threaded AVX2 and BMI2 versions indeed produce different results (on exactly the same settings and starting from an empty hash table etc.), then there might be a bug. (Unless the discrepancy is known and a...
by syzygy
Mon Jun 14, 2021 11:04 pm
Forum: Computer Chess Club: General Topics
Topic: Fluctuations in Stockfish evaluation
Replies: 16
Views: 3717

Re: Fluctuations in Stockfish evaluation

I wonder what is the origin of these unpleasant fluctuations and if there is a solution. What would be the point of searching longer/deeper if fluctuations did not exist? If you don't want fluctuations, search to depth 1. On the other hand, I don't understand the discrepancy between the results of ...
by syzygy
Tue May 25, 2021 8:44 pm
Forum: Computer Chess Club: General Topics
Topic: is this an issue with missing DTZ ?
Replies: 12
Views: 4927

Re: is this an issue with missing DTZ ?

Do you really have the same problem again? Lose, lose, draw, lose, lose with MultiPV = 5 in the same position? hello syzygy, thx for your response :-) ...no, in the pos from above SF shows correctly Kc5 as the only drawing move and shows -153 or so for all other moves ProbeLimit was set on default ...
by syzygy
Thu May 06, 2021 11:58 pm
Forum: Computer Chess Club: General Topics
Topic: is this an issue with missing DTZ ?
Replies: 12
Views: 4927

Re: is this an issue with missing DTZ ?

Do you really have the same problem again? Lose, lose, draw, lose, lose with MultiPV = 5 in the same position?
by syzygy
Thu May 06, 2021 11:46 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Nalimov errors
Replies: 16
Views: 7749

Re: Nalimov errors

That is a good point, and one I had overlooked. Yes, block size is an optional parameter to DATACOMP.EXE. Importantly the default value is 64k, not the 8k which was the value, if I remember correctly, that was used to compress for the official release. Bob Hyatt has posted multiple times about his ...
by syzygy
Tue May 04, 2021 6:37 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Nalimov errors
Replies: 16
Views: 7749

Re: Nalimov errors

Hmm. The potential of bit-rot of the Nalimov generator is curious (i.e. ranging from unexpected to mildly alarming). Given that Jonathan said he ran datacomp, and that his md5sum command is running against an .emd file, my suspicion is that datacomp has not survived the transition from 32-bit to 64...
by syzygy
Mon May 03, 2021 12:11 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Nalimov errors
Replies: 16
Views: 7749

Re: Nalimov errors

So there is a pragma pack in the Nalimov code to ensure packing on a stated boundary so that the change from 32 to 64 bit addressing (or other packing rule such as one byte boundaries for space saving) had no effect? I did not see it in my copy of the code. Without ever having looked at the source ...
by syzygy
Sat May 01, 2021 7:13 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Nalimov errors
Replies: 16
Views: 7749

Re: Nalimov errors

Great, thank you! Yes mine are larger. When I decompress the downloaded files, they are the same size as the generated files. I haven't checked the checksums, yet, but that looks like the answer. It certainly won't have anything to do with modern compilers "tending to pack on wider block sizes". Ho...