Fizbo version 1.4 released

[ymatioun]

I just released version 1.4 of my engine Fizbo. It can be downloaded from https://sites.google.com/site/fizbochessengine/.

Here are release notes:

1. various small modifications to search and evaluation, resulting in approximately +30 ELO.
2. engine can now change size of main transposition table on the fly, using Xboard protocol command "memory N". Size of TT is rounded to nearest power of 2.
3. engine can now use 3-4-5 piece syzygy endgame bit-bases and table-bases. Path of syzygy tables can be passed to the engine using Xboard protocol command "egbpath TYPE PATH". On engine start-up it is also taken from environmental variables DTZDIR and WDLDIR, for DTZ and WDL tables respectively.
4. parallel search is now more advanced, allowing multiple active split-points at the same time. This should improve performance on 8 and more CPU cores (sadly, performance on 4 cores is mostly unchanged, aside from increased strength of single core engine).

Please use this version in the 53rd amateur series division 2 tournament that is about to start.

Youri.

[Graham Banks]

Thanks Youri. Will do.
Division 2 starts later today.

[Graham Banks]

Werner (CEGT) posted in Talkchess that he had to use the following init string to get hash and tablebases working correctly:

xboard memory 256 egtpath type f:\sbases\

[ymatioun]

Memory: right. By default main TT is 128 Mb, and "memory "command would change that.

EG TB: that is what i used, and it worked. For "egtpath type" technically type should be "syzygy", but my engine looks at that directory no matter what the "type" is, to see if there are any syzygy files in there, and if there are, i use them.

Youri.

[Graham Banks]

For Division 2 my tb files are in H:\SyzygyTablebases.
I'm currently using Fizbo with wb2uci.
Could you post what the wb2uci.eng file should look like?

[Jack]

Memory: right. By default main TT is 128 Mb, and "memory "command would change that.

EG TB: that is what i used, and it worked. For "egtpath type" technically type should be "syzygy", but my engine looks at that directory no matter what the "type" is, to see if there are any syzygy files in there, and if there are, i use them.

Youri.

Hi Youri,

I haven't been able to change the hash size either, whether using native wb or wb2uci.eng. If using native wb, it will try to grab as much RAM as possible
which makes my system unstable. It does not seem to recognize the InitString memory command in Arena.

I've also noticed that it played some strange blunders, hanging pieces, in a few of the games, which I'll post later.

Thanks for all your efforts,
Jack

[ymatioun]

I loaded updated executables of Fizbo 1.4 to https://sites.google.com/site/fizbochessengine/. I made 2 changes to them:

1. i hardcoded default EGTB path of H:\SyzygyTablebases into executables; they will look in that directory first, and if syzygy EGTB files are there, they will be used. Otherwise, command "egtpath" could be used to set path of syzygy files.

2. i found a bug in memory allocation, which occurs when size of main hash is changed and large memory tables could not be used; perhaps this is what Jack saw. I fixed that bug, so now memory reallocation should work.

Everything else is unchanged.


WB2UCI: i played with it, and i think this works, at least for passing hash size to the engine:

[ENGINE]
Name=Fizbo 1.4
Author=Youri Matiounine
Filename=Wb2Uci.exe

[OPTIONS]
Program=fizbo14x64.exe
HashCommand=memory %i
Visible=Ponder,Hash,Extras

[EXTRAS]
NalimovPath=egtpath syzygy|string|H:\SyzygyTablebases


Youri.

[Graham Banks]

Thanks Youri - I'll try it.

[Jack]

Thanks Youri,
This is the wb2uci.eng file that I've been using after toying around with the InitString command.

[ENGINE]
Name=Fizbo 1.4 x64 MP
Author=Youri Matiounine
Filename=FizboUCI.exe

[OPTIONS]
Program=fizbo14x64.exe
TerminateHard=true
InitString=xboard cores 2 memory 256 egtpath syzygy c:\syzygy\
MateScore=10000
Noise=9
Visible=Ponder,Logfile

Since I switched to the above file, I haven't noticed any more strange blunders. Please note that setting Memory to 264 gives a hash size of about 440 MB, while setting it to 128 gives around 300 MB.

Of course, I'll also test the new exe ASAP.

Jack

[ymatioun]

Jack:

"InitString" looks like the best way to initialize all the options - thanks for pointing this out.

And if you still see problems with memory of bad moves, let me know and I'll investigate.

Youri.

[Graham Banks]

Fizbo 1.4 64-bit Gauntlet for CCRL 40/40 starts on Friday 22nd May in port 16076.