Fizbo version 1.5 released

[ymatioun]

Version 1.5 of Fizbo chess engine has been released, and is available for download from https://sites.google.com/site/fizbochessengine/. Please use this version for all future CCRL tournaments.

Changes from prior version:

1. I switched it to UCI protocol: this should make it more compatible with modern chess interfaces.I tried running it under cutechess-cli, Winboard, Arena, ChessGUI - they all worked. I implemented all UCI commands, except for debug mode and search with parameters "searchmoves/depth/nodes/mate/movetime". These are not used in actual games, so it should not cause any problems.

2. I made various improvements, mostly to search. As a result playing strength should be improved by around 40 ELO. I ran a match of 400 games, Fizbo1.5/1 CPU vs Fizbo1.4/1 CPU, 40 moves in 4 minutes, 256 Mb hash; result was +38 ELO.

3. i think i fixed the bug in parallel search: i still don't know what the bug was, but i made many changes to parallel search and the bug does not seem to occur anymore. I ran a match of 200 games, Fizbo1.5/4 CPU vs Fizbo1.4/1 CPU, 40 moves in 4 minutes, 512 Mb hash; result was +111 ELO. So strength increase due to using 4 CPUs was +73 ELO - not great, but reasonable.

Youri.

[Graham Banks]

Thanks Youri.

[Graham Banks]

From Werner (CEGT)

Thanks Youri and Graham,
when I start the engine inside command prompt I see:

Found 0 syzygy tablebases.
Found 0 syzygy tablebases.
uci
id name Fizbo 1.5
id author Youri Matiounine
option name Threads type spin default 1 min 1 max 60
option name Hash type spin default 128 min 1 max 16384
option name NalimovPath type string default c:\
option name Ponder type check default false
uciok

So what settings work: syzygy or Nalimov and how?
Can you please contact Youri ?

best wishes
Werner

My reply:

I will do that. It's been causing headaches for me as well.
It should be named SyzygyPath and not NalimovPath.

I can't get Fizbo working on some machines due to this.

[Graham Banks]

Gerhard (CEGT):

Inside the code of Fizbo you can find:
H:/SyzygyTablebases
this causes the problems.
I've changed that with an Hex-Editor
into: D:/ ...

Best wishes,
G.S.

[ymatioun]

The way to pass tablebase path is:
“setoption name NalimovPath value c:\chess\tb\4;c:\chess\tb\5” - path separated by semicolon. This is straight from the UCI specs.
In addition, at start-up engine looks for SYZYGY tables in H:/SyzygyTablebases (hard-coded path specifically for CCRL), and in environment variables "DTZDIR" and "WDLDIR" (from the original SYZYGY code).


So if you include path of SYZYGY tables on the list of paths in the "NalimovPath" option - which allows multiple paths - it should work.

Alternatively, if you want, i can add option "SyzygyPath" with the same functionality as "NalimovPath". I'll need to recompile the code and upload it, so let me know if you want me to do it.

Youri.

[Graham Banks]

The way to pass tablebase path is:
“setoption name NalimovPath value c:\chess\tb\4;c:\chess\tb\5” - path separated by semicolon. This is straight from the UCI specs.
In addition, at start-up engine looks for SYZYGY tables in H:/SyzygyTablebases (hard-coded path specifically for CCRL), and in environment variables "DTZDIR" and "WDLDIR" (from the original SYZYGY code).


So if you include path of SYZYGY tables on the list of paths in the "NalimovPath" option - which allows multiple paths - it should work.

Alternatively, if you want, i can add option "SyzygyPath" with the same functionality as "NalimovPath". I'll need to recompile the code and upload it, so let me know if you want me to do it.

Youri.

I think it would be best to add SyzygyPath as well.
H drive was only a usb stick on one of my computers.

[Graham Banks]

http://www.talkchess.com/forum/viewtopic.php?t=57288

Time losses are an issue as well.

[Ray]

I think it would be best to add SyzygyPath as well.

Sounds like it should be "instead of", not "as well as" - it doesn't support both does it ?

[ymatioun]

I added option "SyzygyPath". It does the same thing as "NalimovPath". The engine only supports syzygy EGTBs, but their path can be passed to engine under either of those two options. If there are no syzygy files in that path, then syzygy EGTBs will not be used.

Updated executables are posed on https://sites.google.com/site/fizbochessengine/.

Time losses: i did not see them in my testing. I can only hope that they are caused by small excess of time over allowed limit, so i increased the time margin in my engine - hopefully this will fix the problem. If the problem persists, i would probably need to see a log of all traffic between GUI and engine.

Youri.

[Graham Banks]

Thanks Youri.

[Graham Banks]

It has been suggested that it would be best to remove the Nalimov one altogether.

[ymatioun]

Graham:

as requested, i removed search of SYZYGY tables in default path of "H:/SyzygyTablebases". Updated executables are on my site.

I also made a small bug fix to parallel search only (single CPU search is unchanged).

Youri.

[Graham Banks]

Thanks Youri. Just got them.