Arasan 20.5

[jdart]

Arasan 20.5 is available from: https://www.arasanchess.org.

Changes in Arasan 20.5:
1) Have tuner output objective value to params file.
2) Bug fix in more() function of RootMoveGenerator.
3) Fixes to Syzygy code: enable locking when multi-threaded.
4) Fix very shallow search when MultiPV greater than the number of legal moves.
5) Fix UCI score output when tb hit at root - now outputs score based on tb score
(worked with multipv but not when multipv == 1).
6) Do not exit search for forced mate if UCI and search type is fixed depth or fixed time.
7) Don't execute move after UCI "bestmove" Wait for GUI to send position.
8) Remove Nalimov and Gaviota tb support.
9) Fix mate score output in GUI.
10) Add code to save/restore window flags and state in GUI.

I expect this version to perform pretty much on a par with Arasan 20.4: all the changes are basically bug fixes, not performance improvements. But some of the fixes are significant: in particular, the tablebase code fixes may prevent occasional crashes when running multithreaded with tablebases in use.

--Jon

[tpoppins]

Thank you muchly for these fixes, Jon.

We will most likely run at least some blitz tests on the new version, and if proves to be same strength as v20.4(.1) we could probably merge them.

[Graham Banks]

Thanks Jon.

[tpoppins]

An 840-game blitz gauntlet confirmed that the new version is on par with v20.4.1 Elo-wise. The most important thing about the new version is that there was not a single game terminated prematurely due to a stalled connection or a disconnect. Syzygy probing now seems to behave as expected both under Fritz GUIs in Infinite Analysis mode and under Cute Chess GUI playing games.

Kudos for ironing out all the kinks, Jon.

[jdart]

Some explanation of what was fixed is in my blog:

https://arasanchess.org/blog.shtml.

--Jon