After a quite long time the new ChestUCI version 3.8 is ready -
and this version is really a revolution in the development of Chest/ChestUCI!
Already since a long time I?ve missed a very efficient matesolving function
in Chest: the restriction to so-called ?threat moves?, i.e. moves which
(after a nullmove of the opponent) would ?threaten? a mate within the next
few moves.
So I?ve again and again tried to convince the Chest-author Heiner Marxen
of this fantastic feature, and finally he has taken pity on me, and has
implemented these ?threats? in my WinChest-version - and there?s no doubt:
He has really created a masterpiece!
Furthermore he has also made a small improvement for problems with special
parameters (independent of these ?threats?), which reduces the solution
times for many of those problems - the highest speed-up factor I?ve found
yet was about 12 (!) for a mate in 42.
So let me say here once again "many thanks" to Heiner for his kind support
and his excellent art of programming - what would computer chess be without
such great people!!!
Well, there are now 2 additional special-options in this new version, called
?ThreatDepth? and ?ThreatRange?, which allow to adjust the wanted depth/range
of these ?threat moves?. Of course I?ve also included this new feature in the
Automatic-mode of ChestUCI, and so this function can also be used in a quite
simple way, without having any special knowledge about it and without the need
for experimenting with complicated engine settings.
The detailled explanation and handling of these new options are described
in the program manual ?English.txt? - simply search for ?ThreatDepth? and
?ThreatRange?.
Maybe it?s better to show some results of this new impressive function than
making long explanations - so here are 2 examples of mate problems comparing
the current with the previous version:
Mate in 16:
1Nb5/2p1pp2/5np1/1pp1rp2/2R4P/1N2kpP1/1K1R4/8 w - -
with ChestUCI 3.7: almost 11 hours (already with special parameters!)
with ChestUCI 3.8: less than 1 sec (with the new ThreatDepth R1)
Mate in 25:
8/1p6/8/pBP4r/p3R2P/K7/3p1p1p/3k4 w - -
with ChestUCI 3.7: without threats practically unsolvable!
with ChestUCI 3.8: less than 1 sec (again with ThreatDepth R1)
And the best is: these optimal solutions are even found in Automatic-mode
within only a few seconds - there?s no need to find out the best settings
by manually trying complicated engine settings!
More examples can be found in my Mate-file ?Mate.epd?, which is included
in ChestUCI - currently it contains already about 850 mate problems.
In this file I?ve already adapted the format of the special-parameters
for the new version, but (because of the big number of problems) I had
no time yet to solve them all with the current version, so the solution
times are for the old version 3.7 and ?ThreatDepth? is simply set to ?R0?.
With this new version there?s now the possibility of solving a large number
of additional chess problems, where older ChestUCI-versions had absolutely
no chance. But of course there are still a ?few? positions, which can?t be
solved despite of this new ?threat? function:
e.g. ChestUCI has still a bad time with the chess startposition -
but would we really like to solve the complete game of chess?
As usual ChestUCI 3.8 can be found at the following link:
http://www.uciengines.de/UCI-Engines/Chest/chest.html
Enjoy this new super-version,
Franz.
