Help for Syzygy probe?

Discussion of chess software programming and technical issues.

Moderators: bob, hgm, Harvey Williamson

Forum rules
This textbox is used to restore diagrams posted with the [d] tag before the upgrade.
kinderchocolate
Posts: 411
Joined: Mon Nov 01, 2010 5:55 am
Full name: Ted Wong
Contact:

Re: Help for Syzygy probe?

Post by kinderchocolate » Wed Dec 07, 2016 12:16 pm

Thanks to Basil and Greg.

I understand I have incomplete database files, in fact I don't have any 5-men file. I was curious why two different programs, giving the same physical path and FEN would return different results.

I am using the Fathom tool. I compiled your code in the apps directory. I only want the TB result and nothing more. This was what I did:

./fathom.macosx --path=ABCD --test "4k3/3bb3/4b3/8/5p2/8/8/4K3 w - - 0 1"

where "ls ABCD/KBBBPvK*" gives me:

ABCD/KBBBPvK.rtbw ABCD/KBBBPvK.rtbz

The command returns "error: unable to probe tablebase; position invalid, illegal or not in tablebase".

Apparently, the --test option is not able to tell me the TB result.

basil00
Posts: 55
Joined: Thu Oct 22, 2015 12:14 am

Re: Help for Syzygy probe?

Post by basil00 » Wed Dec 07, 2016 10:00 pm

kinderchocolate wrote:./fathom.macosx --path=ABCD --test "4k3/3bb3/4b3/8/5p2/8/8/4K3 w - - 0 1"

where "ls ABCD/KBBBPvK*" gives me:

ABCD/KBBBPvK.rtbw ABCD/KBBBPvK.rtbz

The command returns "error: unable to probe tablebase; position invalid, illegal or not in tablebase".

Apparently, the --test option is not able to tell me the TB result.
I had a look. It is failing because the Fathom tool calls probe_root() which attempts to calculate both the WDL and DTZ values. In order to calculate the DTZ value, it needs to probe the KBBBvK WDL table, which is missing.

This is a small bug in the Fathom tool: for the --test mode, it is not necessary to call probe_root(). Rather probe_wdl() would suffice.

kinderchocolate
Posts: 411
Joined: Mon Nov 01, 2010 5:55 am
Full name: Ted Wong
Contact:

Re: Help for Syzygy probe?

Post by kinderchocolate » Thu Dec 08, 2016 8:16 am

Thanks. That solves the problem :-)

Post Reply