Author: Javier Ros Padilla
Date: 08:48:08 11/07/03
Go up one level in this thread
On November 06, 2003 at 13:45:45, margolies,marc wrote:
>wow, that's intersesting. I suppose that if there are exchanges before promotion
>it's ok.
>I am wondering if your outcome of success was predicated on the kind of position
>you examined or if the answer is universal.
>
>
>On November 06, 2003 at 04:12:29, Javier Ros Padilla wrote:
>
>>On November 05, 2003 at 19:22:33, margolies,marc wrote:
>>
>>>if you only plan to download 2 6pc-EGTBs, then avoid chosing a base with a P in
>>>the name-- because it refers to other bases after pawn promotion thus making it
>>>unusable without subtables.
>>
>>I think you can use them without subtables, after promotion the engine and the
>>available tablebases must help in normal play.
>>
>>For example with the KRPP-KR tablebase 4.7 Gb you can analyze a single position
>>without consulting the subtables.
>>
>>Javier Ros
>>
>>
>>>
>>>
>>>On November 05, 2003 at 18:11:52, Torstein Hall wrote:
>>>
>>>>I planned to download one or two 6 man tabelbases if I can find any. Is there
>>>>one or two I should prefer?
>>>>
>>>>Torstein
see this text extracted from
http://www.aarontay.per.sg/Winboard/Winboard3.html
author Aaron Tay
[C.7] How many tablebases do I need? Can I download only some of them?
The more tablebase files you install, the stronger the program will be. However,
a full set of 3,4 and 5 Tablebase files takes about 8 GB of Hard disk space!
Most people download a full set of 4 Piece databases and select only a few of
the 5 pieces.
Generally the 5 piece endgames with rooks are reached most frequently and should
be downloaded . However, there are some pitfalls that you should be aware of.
If you want to use the KRPKR tablebase [and assuming you have all the 3 and 4
tablebases], make sure that you have the following endgame tablebases as well,
KQRKR, KRBKR, KRRKR, KRNKR, . This is to ensure that the promotion cases are
included.
If you lack say the KQRKR tablebase, some programs refuse to queen the pawn in
the KRPKR even if that would lead to a win, because such a move, would cause the
program to drop from a position flagged as "win", to a position that is
uncertain since they lack the relevant endgame table.
A similar problem can result if you download only the KQPKQ tablebase without
KQQKQ , KQRKQ etc..
Some programs like Crafty and Yace are "smart" enough to avoid this problem, but
most like Amy , or The Crazy Bishop cannot handle this.
Also take note that not all programs support all the Tablebases. Yace for
example, currently does not use the 4+1 tablebases [ King and 3 pieces/pawns on
a side versus a alone King] , because such positions are easily won most of the
time barring rare cases [Like double rook pawns, wrong coloured bishop and King
vers King]. Also I think only Crafty currently, supports 6 piece tablebases.
Szots Gabor also reports that Wildcat , Capture and perhaps Inimichess cannot
handle incomplete 5 men tablebase
Javier Ros
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