[Retros] Natch-2.5Beta

Pascal Wassong pascal.wassong at free.fr
Wed Jul 8 07:59:41 EDT 2009


after all those years, a bug has been found in Natch by Roberto
Osorio. For example, Natch 2.4 doesn't solve the following problem :

14 single moves. 15 + 16

The problem is caused by the moves Bc8-d7-c6-d5, necessary because of
Pd7xe6, colliding with the move Ke8-d7.

If you play 7.Qd7 (or 7.Nd7) instead of 7.Kd7, there is no problem.
The problem also disappears if the bK plays another move after passing
by d7. By adding 8.Bc4 Kd6, Natch finds again the solution.

The complete and technical explanation of this bug is a bit longer.

The corrected version Natch-2.5Beta is available in the Beta section
of the Natch page, at http://Natch.free.fr/Natch.html

If there is no other problem signaled in the next few weeks for this
version, it will become the official Natch-2.5 release.

By the way, the compiled version for Windows should also work on

Thank you, Roberto, for finding this problem.


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