#169 tablebase

Database (53)
Luca Daniel

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
[+] Tablebase: 4...Nc7+ - Draw

The correct move is 4.e8=R
I've made an youtube video:

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


  • Jens Nissen

    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.

  • Jens Nissen

    Jens Nissen - 2013-05-02

    The bug has been fixed in SVN.

  • Jens Nissen

    Jens Nissen - 2013-05-02
    • assigned_to: mrudolf --> hognose
    • status: open --> closed-fixed
  • Jens Nissen

    Jens Nissen - 2013-05-02

    Committed revision 1462.


Get latest updates about Open Source Projects, Conferences and News.

Sign up for the SourceForge newsletter:

No, thanks