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Subject: new ChestUCI Ver.3.0 - the final version!

Author: F. Huber

Date: 09:44:14 12/02/03


Hello Chest friends!

Now I´ve also implemented my last ideas for ChestUCI, and so here is
(as an early Christmas present ;-)) the recent (and probably definite)
version 3.0 of ChestUCI.

What´s new?

At first a few minor changes:
- displays immediately, when the search process is completed
- recognizes itself, if the start position is mate or stalemate
- output optimal adapted to the capabilities of the Shredder GUI
- better treatment of special cases with ´DefenderMoves´ and the
  problem types ´self/help-mate/stalemate´
- extended input possibilities for parameters in ´Expert mode´

Additionally now I´ve also included my little test file (´Mate.epd´)
with about 170 (from very easy to extremely hard) mate problems from
different fora for trying.

Now about the more important enhancements:

1) a new option ´FullMovelist´:
Normally (i.e. in earlier versions, and with this option switched ON)
ChestUCI provides the complete move tree as solution for a problem,
i.e. a solution variant for every possible opponent move.
In rare cases (at problems with a large search depth or a lot of possible
moves) this could lead to a very long time to produce the complete move tree,
although the solution has already be found much earlier.

A small example for this behaviour (and not even the most extreme one!):
4k3/8/4pPp1/3pP1P1/2pP1K2/2P5/8/8 w - -
That´s a mate in 18, where my (slow) computer needs about 15 sec to find
the mate, but after that it takes another 2 min (!) to calculate and
produce the full solution file (with a size of 24MB!).

By switching OFF this new option, in such cases now you can avoid the
calculation of the complete move tree and you´ll get the solution
immediately after the successfull mate searching.
Nevertheless you´ll still get a complete main line (PV) for every solution,
but simply not for all possible opponent moves.

2) a further new option ´ShowStatistics´:
If this option is activated, then after each completed search depth ChestUCI
shows detailed informations about the previous calculation, which can give
a rather good indication to the further calculation process.

Such an info line could look like this:
d=7  t=150.22s [9.30]  n=11957kN [9.56]   Hash: spd=3.55  in=1114866 out=18447

The values for depth(d), time(t) and nodes(n) are probably clear - the two
numbers in [...] are the so-called ´effective branching factors´ (EBF),
separately for time and node, and mean the ratio of the value for the current
search depth to the value for the previous search depth ( in other words: the
factor which shows, how much more this depth ´costs´ than the last one).
Larger values indicate an already ´exploding´ search tree, what means that the
further calculation could take a rather long time.

The following 3 values after ´Hash:´ are the ´speed-up factor´ (spd) by the
hash table usage (i.e. "how much faster was the calculation WITH vs. WITHOUT
hash table"), the number of entries written to the hash table and the number
of deleted (or overwritten) hash table entries.
These values also provide an indication for the efficiency of the hash table
administration and show, if the hash size setting is sufficient.

Surely these ´statistics´ are rather ´technical´ informations, but maybe a few
people are interested in it, since there are a lot of experts here. ;-)

Now such a ´complete´ output of a problem solution by ChestUCI could look
as following: (a copy from the analyse window of Arena 1.0!)

------------------------------------------------------------------------------
ChestUCI Ver.3.0  UCI:

CPU: Celeron 400MHz
FEN: 8/1K6/8/8/8/3N3R/n7/kb5R w - -
Search for Mate in 10 ...  (Hash=64MB)
d=1  t=0.05s [1.00]  n=0kN [1.00]   Hash: spd=1.00  in=1  out=0
d=2  t=0.11s [2.20]  n=0kN [1.00]   Hash: spd=0.99  in=1  out=0
d=3  t=0.22s [2.00]  n=1kN [14.88]   Hash: spd=0.99  in=34  out=0
d=4  t=0.38s [1.73]  n=11kN [11.94]   Hash: spd=1.35  in=774  out=0
d=5  t=2.31s [6.08]  n=120kN [11.24]   Hash: spd=1.92  in=11422  out=0
d=6  t=16.15s [6.99]  n=1250kN [10.44]   Hash: spd=2.50  in=124360  out=0
 7   01:29  M7  Rh4
 7   01:42  M7  Rh8
d=7  t=150.22s [9.30]  n=11957kN [9.56]   Hash: spd=3.55  in=1114866 out=18447
Search completed ...  (Time=150.22s)
Mate in 7 found !  (2 Solutions in 02:30)
 7   02:31  M7  Rh8 Nb4 Ra8+ Na2 Ka6 Nb4+ Kb5+ Na2 Ka4 Nc1 Rxc1 Ka2 Kb4+
 7   02:31  M7  Rh4 Nc3 Rc4 Ka2 Rxc3 Bxd3 Rxd3 Kb2 Rh2+ Kc1 Rf3 Kb1 Rf1+
------------------------------------------------------------------------------

Ok, that´s the end of my detailed description of the new possibilities -
now I wish you much fun with this new verion, which is again - as usual -
downloadable from Alex´ UCI-homepage:

http://www.uciengines.de/UCI-Engines/Chest/chest.html

With my best regards,
Franz.



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