Critter 0.70 is out

[rvida]

Download link:
Critter 0.70

This version supports Gaviota tablebases.

New UCI options:

"GTB Path": Folder where tablebase files are located (default value: \gtb)
"GTB Cache": Size of tablebase cache in magabytes (dafault 32)
"GTB Compression": tablebase compression scheme (default "cp4")

"GTB Usage":
"Disable": Turn off tablebase probing. Useful for debugging/troubleshooting
"Only At Root": This does not slow down the search and allows for optimal play with less than 6 pieces left on the board
"Everywhere": Probe tablebases in search tree. IMO it is worth only for analysis. While it helps in some positions, it slows down the search too much and the engine is actually _weaker_ with this setting.

Strength:

In direct match against Critter 0.60 it is nearly 100 elo stronger.
It performs quite good against Komodo, Naum, even Shredder, but still gets eaten alive by Stockfish (especially in endgames).

Enjoy,

Richard

[Martin Thoresen]

Very nice, will try out at once!

Thank you!

[yanquis1972]

100 elo?? didn't .60 come out 2 days ago???

[Martin Thoresen]

100 elo?? didn't .60 come out 2 days ago???

0.60 was released around 15th of April.

[michiguel]

Download link:
Critter 0.70

This version supports Gaviota tablebases.

New UCI options:

"GTB Path": Folder where tablebase files are located (default value: \gtb)
"GTB Cache": Size of tablebase cache in magabytes (dafault 32)
"GTB Compression": tablebase compression scheme (default "cp4")

"GTB Usage":
"Disable": Turn off tablebase probing. Useful for debugging/troubleshooting
"Only At Root": This does not slow down the search and allows for optimal play with less than 6 pieces left on the board
"Everywhere": Probe tablebases in search tree. IMO it is worth only for analysis. While it helps in some positions, it slows down the search too much and the engine is actually _weaker_ with this setting.

Hi Richard,

Have you tried probing soft (not hard) in the <n> plies close to the leaves? This <n> needs to be calibrated for each engine, but you can find a condition in which the slow down is negligible. In that situation, the engine cannot be weaker.

Miguel

Strength:

In direct match against Critter 0.60 it is nearly 100 elo stronger.
It performs quite good against Komodo, Naum, even Shredder, but still gets eaten alive by Stockfish (especially in endgames).

Enjoy,

Richard

[rvida]

Hi Richard,

Have you tried probing soft (not hard) in the <n> plies close to the leaves? This <n> needs to be calibrated for each engine, but you can find a condition in which the slow down is negligible. In that situation, the engine cannot be weaker.

Miguel

Yes, I tried it. The slowdown was indeed almost negligible, but the search accuracy was badly degraded. After a soft probe cache miss the transposition table gets polluted with inaccurate scores. Critter's search then finds some unbelievable ways to avoid lines where tablebase probes were successful.

Richard

[Matthias Gemuh]

"GTB Path": Folder where tablebase files are located (default value: \gtb)
"GTB Cache": Size of tablebase cache in magabytes (dafault 32)
...
Richard

Official names which ChessGUI automatically recognizes and configures are GaviotaTbPath and GaviotaTbCache.
I hope Miguel will document this somewhere

Under ChessGUI, users do not need to individually configure NalimovPath, NalimovCache, GaviotaTbPath nor GaviotaTbCache for each UCI engine.

Matthias.

[Werner]

Hi Richard,
thanks for the engine!

I have a question:

What is the correct setup if I have gtb in 2 folder
c:\gtb4 and
c:\gtb5

[mhalstern]

Richard,

I'm about to play a gauntlet. Before I do - what is the best gtb cache value. My Pc has 6 gigs of RAM and plenty free when running an engine match. Should I increase this value?

Thanks

[mcostalba]

In direct match against Critter 0.60 it is nearly 100 elo stronger.

Wow !!!

Congratulations Richard !

I think Critter togheter with Komodo are the two rising stars. I expect them to quickly reach the top.