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Ernest Bonnem · Joined: 08 Mar 2006 Posts: 1271

Maybe Dan or somebody else can help...

With Scorpio 2.0 (date: end 2007 Cool

), I have no problem in 5-man bitbase access, even with the new (Dann Corbit compressed - 223 MB) bitbases and the v3.3 egbbdll. My test is mostly in 32-bit.

I wanted to test with the more recent Scorpio 2.7 version.
I use the Fritz 11 and Shredder GUIs.

Since Scorpio is Winboard, you have to use Wb2uci and Wb2Uci.eng
The Scorpio configuration file, scorpio.ini defines the
#path to egbb
egbb_path C:\egbb\

Note that if you skip the last \ , the path is not recognized! Surprised

I shut off all access to Nalimov GUI access and used the 5-man position
8/8/8/8/5kp1/P7/8/1K1N4 w - - 0 1 ; bm Kb1-c2; dm50
(only solution Kc2, never found without tables or bitbases)

Well, with version 2.7 of Scorpio (the latest), and for that matter any version later than 2.0:
_ on infinite analysis, no output, depth stays at 1
_ on "compute", I get the immediate move (correct move, "depth 1" eval?)
Analysis by Scorpio 2.7:
1.Kc2
= (0.00) Depth: 1 00:00:00

as compared to the correct

Daniel Shawul · Joined: 14 Mar 2006 Posts: 2185 Location: Ethiopia

Hmm Scorpio seems to give you a bit of a headache there. I have countless number of reports with this kind of problem. The most probable cause for egbb problems is non-compatible version of the probling dll with egbbs used. When you download the egbbs use the dll inside there, don't download elsewhere and put it in the new dlls there.
If your bitbase size is about 220MB then use the new ones.
If your bitbase size is about 365MB then use the old ones.
Check that and we will go from there.
Cheers
Edit Wait your problem seems to be different. In the position you provided 8/8/8/8/5kp1/P7/8/1K1N4 w - - 0 1 , all the moves lead to draw with best play so it just picks one and make it.
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Ronald de Man · Joined: 28 Feb 2012 Posts: 839

I suppose Scorpio only searches winning moves when the root position is in the bitbases. In this position, the only winning move is Kc2. Since there is only one move to search, a 1-ply search will do.

edit: oops, this answer would have made sense were it not for the incorrect 0.00 score returned...

Ronald de Man · Joined: 28 Feb 2012 Posts: 839

Daniel Shawul · Joined: 14 Mar 2006 Posts: 2185 Location: Ethiopia

I am the one who is confused... I think he may have found a bug. But I forgot scorpio code so much..c is ugly to look at Smile

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Daniel Shawul · Joined: 14 Mar 2006 Posts: 2185 Location: Ethiopia

Ernest, it is working fine I think. It is because of some complicated code I put to cull root moves that lead to inferior score when being in egbb. So for <= 5 man positions, the root is already inside egbb and any move that leads to a score less than or equal to the root score by a good margin is culled out. So if the root says draw 0 score , then all the moves that loose are removed. If the root score is a win, then all moves that draw or loose are removed.
So in those situations it can sometimes end up with only one move to play. Typically for test suites there is only one good move to play and this happens a lot. I just run it on MES testsuite, the first 20 or so positions were solved at ply 1 this way. My motive was to make moves very quickly and save time. I think your are good to go, just remember this when analyzing positions with <=5 men.
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Ernest Bonnem · Joined: 08 Mar 2006 Posts: 1271

Daniel Shawul · Joined: 14 Mar 2006 Posts: 2185 Location: Ethiopia

Guenther Simon · Joined: 01 Oct 2008 Posts: 334

Ernest Bonnem · Joined: 08 Mar 2006 Posts: 1271