ChessX / Bugs / #169 tablebase

#169 tablebase

Status: closed-fixed

Owner: Jens Nissen

Labels: Database (53)

Priority: 5

Updated: 2013-05-02

Created: 2013-04-29

Creator: Luca Daniel

Private: No

I don't know how much this is related to chessx but I've found a situation where the tablebase is wrong, here is the FEN:
K2B4/4P3/k7/3n4/8/8/8/8 w - - 1 4

[+] Tablebase: 4.e8=Q - White wins in 21 moves
4.e8=Q
[+] Tablebase: 4...Nc7+ - Draw

The correct move is 4.e8=R
I've made an youtube video:
http://www.youtube.com/watch?v=x_Wbru3SSMA

I don't know what tablebase chessx uses but somebody should recheck it !

Discussion

Jens Nissen - 2013-05-02

Amazing - a very old bug in the commonly used function prepareMove, that makes all tablebase moves which contain a underpromotion promote into a queen instead. Need to check other calls to the same method.

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Jens Nissen - 2013-05-02

The bug has been fixed in SVN.

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Jens Nissen - 2013-05-02

assigned_to: mrudolf --> hognose

status: open --> closed-fixed
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Jens Nissen - 2013-05-02

Committed revision 1462.

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#169 tablebase

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