Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: PDA

Author: Mike Byrne

Date: 16:27:32 10/21/03

Go up one level in this thread


On October 21, 2003 at 19:26:08, Mike Byrne wrote:

>On October 21, 2003 at 19:24:59, Mike Byrne wrote:
>
>>On October 21, 2003 at 11:53:02, Tord Romstad wrote:
>>
>>>I don't run my engine through WAC very often, but before releasing a new
>>>version (which I will do within a couple of days) I run the whole suite as
>>>a sanity test.  This time, the following position made me worried:
>>>
>>>[D]8/8/2Kp4/3P1B2/2P2k2/5p2/8/8 w - - bm Bc8; id "WAC146";
>>>
>>>Previously, my program had no problems with this position.  The new
>>>version, which is the first one to include tablebase support, prefers
>>>Bd3 instead of Bc8.  At ply 21, the score is +12 for white.  When I
>>>disable tablebases, the program plays Bc8.
>>>
>>>Does Bd3 also win, or should I look for yet another bug?
>>>
>>>One of the hardest positions in WAC for my engine is number 163:
>>>
>>>[D]5rk1/2p4p/2p4r/3P4/4p1b1/1Q2NqPp/PP3P1K/R4R2 b - - bm Qg2+; id "WAC163";
>>>
>>>On a Pentium IV 2.4 GHz, I need 11 plies and 1m53s to find the winning move.
>>>The problem is to find the line 1... Qg2+ 2. Nxg2 hxg2+ 3. Kxg2 Bf3+ 4. Qxf3
>>>exf3+ 5. Kg1 Rf5! followed by Rfh5.  Without nullmove pruning, this position
>>>is solved within a few seconds.
>>>
>>>This is rather annoying, as I have lost more games than I would like on
>>>the ICC because of missing similar tactics.  Are there any inexpensive
>>>tricks to help me solve this kind of positions more quickly?
>>>
>>>Tord
>>
>>Chess Genius sees Qg2 after 31 seconds and is +10 after 2 minutes...
>>
>>The second one  is solved instantly and goes to +8 after 45 seconds...
>
>Should add Pocket Chess Genius 1.5 - Dell Axim oc 472Mhz 16MB hash   blah blah
>blah


I tested the second first and the first one second ...so it sees Bc8 instantly
and Qg2+ after 31 seconds ...sorry the reverse order there...



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.