[Retros] Natch 3.0 beta is out

Pascal Wassong pascal.wassong at free.fr
Fri Jul 29 12:46:52 EDT 2016

Hello all,

19 years after the first version, 7 years after the latest version, a
new version of Natch is out.  It is version 3.0 beta.  You can
download it from http://Natch.free.fr .

Previous version already computed the order of some moves.  This was
used to eliminate position having cycles in it.  For example
Pa2-a8=N-b6*Pa7 and Pa7xb6.  These move orders found for a position are
now used when searching for the moves.  For example, if black must play
Rh8-e8-e3-c3 and white Pe2-e4, the wPe2 won't be allowed to move before
the black rook arrived at c3.  This improvement increase the speed of
resolution of many problems, and makes the --watch (-k for short) preaty

Many more move orders are also found.

A bug has been corrected, where some solutions where not found.

A bug has been corrected on Mac, which made the program crash when the
hash-tables where full.  I was surprised to learn about this problem
so late.

There are also minor changes in the output file and when using the
visual option.

More details about this new version are available in the NEWS file
available when you download the beta version.

There were many bugs in the numerous alpha version while developing this
3.0 version, which have been found by the testers, mainly Michel
Caillaud and Thierry Le Gleuher.  Thanks to them and to the other

There may still be bugs in this version.  If you find one, don't
hesitate to send it to me.  The informations needed are:
- the proof game, being as short as possible, that reproduces the bug;
- the expected solution;
- the number of the position where the bug occurs, if needed;
- a clear description of what is going wrong.

The precompiled version for windows is a 64 bits version.  I could
also prepare a 32 bits windows version, if enough people are

Happy composing,

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