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Subject: Follow-Up: Bugreport?

Author: Eelco de Groot

Date: 15:51:22 09/02/00

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A difficult position it turned out to be for the programs also, Leonid!
Not that the programs I tried cannot find a mate-solution... The programs I
tried are selective, a brute force approach could always give the shortest mate
but would probably also take longer unless it is specifically designed to find
mates.

I hesitate to place this because it turns out more like some bug-report or else
I am doing several things wrong. I'm hoping this does not sound too negative:
when Rebel Century 2.0 for ECTool announces a mate the numbering of the moves
seems to be a little displaced. Not a giant bug. In Crafty's analysis mode I
can't get pawns to promote but maybe there I'm doing something wrong entering
the move.

The Q5T personality for Rebel Century 2.0 in ECTool needs 1 minute 36 to
announce a mate. I think ChessMaster, aka The King, can beat this. Q5T is
similar to Q3, a selective personality and much too aggressive to do well in
games. But good in many tactical positions. This was on my Celeron 500MHz, 28Mb
transposition tables. Unfortunately the engine stops after announcing the mate
and only gives 4 half-moves of a mate in eight, you would like to see the full
mate sequence.

Rebel Engine for ECTool. (c) Ed Schröder

Engine version   :  REBEL CENTURY 2
Rebel personality :  q5t.eng
Opening book file :  REBEL.MVS
Hash table size  :  28 MB
Analysis mode   :  Analyzing next move
Refresh interval : 500 ms

Game begin

00:00  02.00  29.13  1.hxg8=Q+ Qf8 2.Nxe6+ Kc8 3.gxf8=Q+ Qxf8 4.Qxc7+
00:00  02.06  29.21  1.Nxe6+ Kc8 2.hxg8=Q+ Qf8 3.gxh8=Q
00:01  03.01  29.54  1.hxg8=Q+
00:01  03.01  31.82  1.hxg8=Q+ Qf8 2.Qxh8 Qh3+ 3.Qexh3
00:10  04.00  32.69  1.hxg8=Q+ Qf8 2.Qxh8 Qh3+ 3.Qexh3 Qxh3+ 4.Qhxh3
00:21  04.04  32.69  1.fxg8=Q+
00:23  04.04  34.46  1.fxg8=Q+ Qee8 2.Nxc6+ Qdxc6 3.Qa8+ Qxa8 4.Qhh4+
00:24  04.05  34.46  1.f8=Q+
00:41  04.05  37.23  1.f8=Q+ Qde8 2.Nxe6+ Kc8 3.fxe8=Q+ Qcd8 4.exd8=Q+
01:30  04.45  37.23  1.Nxc6+
01:36  04.45  Mate in  1.8 moves 2.Nxc6+ Qdxc6 3.f8=Q+ Qee8 4.Qxc7+ Kxc7

Q3 personality from Eric Campos, winner of the Rebel contest for tactical
positions is fastest so far! Needs 41 seconds to announce a mate.
It gives a mate in 9 and stops looking further, many programs do this, I believe
the shortest mate is a mate in seven Leonid, with several first moves possible?
Different second move for Black here and in the given PV it seems to say that
Nxc6+ is the second move which I think is not correct, it's White's first move.

Rebel Engine for ECTool. (c) Ed Schröder

Engine version   :  REBEL CENTURY 2
Rebel personality :  q3.eng
Opening book file :  REBEL.MVS
Hash table size  :  28 MB
Analysis mode   :  Analyzing next move
Refresh interval : 500 ms

Game begin

00:00  01.00  19.68  1.fxg8=Q+ Qde8 2.Qxe6 Qxh2+ 3.Qxh2 Qcxe6 4.Nxe6+
00:00  02.00  28.71  1.hxg8=Q+ Qf8 2.Nxe6+ Kc8 3.gxf8=Q+ Qxf8 4.Qxc7+
00:01  03.00  31.13  1.hxg8=Q+ Qf8 2.Qxh8 Qh3+ 3.Qexh3
00:10  04.00  31.96  1.hxg8=Q+ Qf8 2.Qxh8 Qh3+ 3.Qexh3 Qxh3+ 4.Qhxh3
00:11  04.01  31.96  1.f8=Q+
00:28  04.01  36.71  1.f8=Q+ Qde8 2.Nxe6+ Kc8 3.fxe8=Q+ Qcd8 4.exd8=Q+
00:33  04.03  36.71  1.Nxc6+
00:34  04.03  36.71  1.Nxc6+
00:41  04.03  Mate in  1.9 moves 2.Nxc6+ Qdxc6 3.f8=Q+ Kd7 4.Qxc7+ Qxc7 5.Qa4+

Finally a possible bug in Crafty? At least I seem to be unable to promote a pawn
in "analyze" mode? Maybe I entered the moves in the wrong way.. I also tried a
simple position like 8/2Pk4/8/8/8/8/8/4K3 w - - and when I try to promote the
c-pawn Crafty 17-11 says it's an illegal move.

Crafty finds a mate in seven in the many queens position and gives the full mate
sequence. Again on the Celeron 500, time is 2 min 48 seconds.

White(1): analyze
              clearing hash tables
              time surplus   0.00  time limit 30.00 (3:00)
         nss  depth   time  score   variation (1)
                4->   1.69  32.25   1. hxg8=Q+ Qf8 2. Qhxh8 Qh3+ 3. Qhxh3
                                    Qxh3+ 4. Qgxh3
                5     1.80     ++   1. hxg8=Q+!!
                5     2.47  35.78   1. hxg8=Q+ Qf8 2. Qhxh8 Rh5+ 3. Qh4+
                                    Rxh4+ 4. Qxh4+ Qde7 5. Nxe6+ Kc8 6.
                                    Qxe7 Qxg2+ 7. Qexg2
                5->  18.82  35.78   1. hxg8=Q+ Qf8 2. Qhxh8 Rh5+ 3. Qh4+
                                    Rxh4+ 4. Qxh4+ Qde7 5. Nxe6+ Kc8 6.
                                    Qxe7 Qxg2+ 7. Qexg2
                6    19.12     ++   1. hxg8=Q+!!
                6    26.09  36.72   1. hxg8=Q+ Qf8 2. Qhxh8 Rh5+ 3. Qh4+
                                    Rxh4+ 4. Qxh4+ Kc8 5. Qa8+ Qxa8 6.
                                    Qxa8+ Qb8 7. Qxf8+ Qd8 8. Qhxd8#
                6    38.17     ++   1. Qxc7+!!
                6     2:17  39.36   1. Qxc7+ Kxc7 2. Nxe6+ Kc8 3. Nb6+
                                    Kb8 4. Qeg3+ Qe5 5. Qgxe5+ Qdc7 6.
                                    Qxc7+ Qexc7 7. hxg8=Q+ Rd8 8. Nxc7
                                    Qxc7 9. f8=Q Rxf8 10. Qgxf8+
                6     2:17     ++   1. f8=Q+!!
                6     2:48  Mat07   1. f8=Q+ Qde8 2. Nxc6+ Qexc6 3. Qxe8+
                                    Qcxe8 4. Qxd5+ Q8d7 5. hxg8=Q+ Qxg8
                                    6. Qaa8+ Qc8 7. Qxe7#
                6->   4:02  Mat07   1. f8=Q+ Qde8 2. Nxc6+ Qexc6 3. Qxe8+


Eelco

The two positions:
[D]3k2nq/2qqqP1P/2q1q3/3r4/2NN4/4Q3/Q3QQQQ/7K w
[D]8/2Pk4/8/8/8/8/8/4K3 w - -



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Last modified: Thu, 15 Apr 21 08:11:13 -0700

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